RIGID FOAMS

Abstract

A rigid foam comprising the reaction product of an (poly)isocyanate, and a polyethercarbonate polyol copolymer is described. The polyethercarbonate polyol copolymer is derived from the copolymerisation of one or more epoxides with CO.sub.2, wherein the total CO.sub.2 content of the polyethercarbonate polyol copolymer is between 1 and 40 wt %, the carbonate linkages are <95% of the total linkages from the copolymerisation, and the molecular weight is between 100 to 5000 g/mol. The foam is a polyurethane foam, more typically, a polyisocyanurate or a mixed polyisocyanurate/polyurethane foam. Methods, polyols and compositions for producing the foams are also described.

Claims

1. A rigid foam comprising the reaction product of an isocyanate or polyisocyanate, and a polyethercarbonate polyol copolymer wherein the polyethercarbonate polyol copolymer is derived from the copolymerisation of one or more epoxides with CO.sub.2, wherein the total-CO.sub.2 content of the polyethercarbonate polyol copolymer is between 1 and 40 wt %, the polyethercarbonate polyol copolymer has m carbonate linkages and n ether linkages, wherein m and n are integers, and m/(n+m) is from 0.2 to 0.7, and the molecular weight of the polyethercarbonate polyol copolymer is from 200 to 3000 g/mol.

2. The rigid foam according to claim 1, wherein one or more further polyols are optionally present during the reaction with isocyanate or polyisocyanate, wherein the polyethercarbonate polyol copolymer forms from 20 to 100 wt % of all the polyols present during the reaction with the isocyanate or polyisocyanate to produce the rigid foam, and optionally wherein the isocyanate or polyisocyanate has a functionality between 2 to 5.

3. The rigid foam according to claim 1, wherein the CO.sub.2 content in the polyether carbonate polyol copolymer is 5-35 wt %.

4. The rigid foam according to claim 1, wherein the ether linkage content of the polyethercarbonate polyol copolymer is at least 30%.

5. The rigid foam according to claim 1, wherein more than 95% of the chain ends of the polyethercarbonate polyol copolymer are OH groups.

6. The rigid foam according to claim 1, wherein the functionality of the polyol copolymer is between 2-6.

7. The rigid foam according to claim 1, wherein the OH content in the polyol is in the range 20-500 mg KOH/g.

8. The rigid foam according to claim 1, wherein the polyethercarbonate polyol which has m carbonate linkages and n ether linkages, wherein m and n are integers, and wherein m/(n+m) is from 0.3 to 0.7.

9. The rigid foam according to claim 1, wherein the polyethercarbonate polyol copolymer is prepared using a starter compound and an epoxide, and have the following formula (IV): ##STR00010## wherein the identity of Z and Z depends on the nature of the starter compound, the identity of R.sup.e1 and R.sup.e2 will depend on the nature of the epoxide used to prepare the polyethercarbonate polyol copolymer, and m and n define the amount of the carbonate and ether linkages in the polyethercarbonate polyol copolymer.

10. The rigid foam according to claim 9, wherein the starter compound is of the formula (III):
Z(R.sup.Z).sub.a(III) wherein Z is any group which can have 2 or more R.sup.Z groups attached to it, optionally, wherein Z is selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z is a combination of any of these groups; a is an integer which is at least 2; each R.sup.Z is independently selected from OH, NHR, SH, C(O)OH, P(O)(OR)(OH), PR(O)(OH).sub.2 or PR(O)OH, and R is H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl; each R.sup.e1 is independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl; each R.sup.e2 is independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl; or R.sup.e1 and R.sup.e2 together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms; and Z corresponds to R.sup.Z, except that a bond replaces the labile hydrogen atom; wherein although the polymer drawn in IV depicts Z bound to the carbon of an ethylene unit from the epoxide, R.sup.Z reacts first with CO.sub.2 if it is OH, SH, NHR, P(O)(OR)(OH), PR(O)(OH).sub.2 or PR(O)OH and in these instances, Z would correspondingly be OC(O)O, SC(O)O, NRC(O)O, P(O)(OR)OC(O)O, PR(O)(OH)OC(O)O or PR(O)OC(O)O.

11. The rigid foam according to claim 1, wherein the polyether carbonate polyol has n ether linkages and m carbonate linkages, and wherein the number of ether and carbonate linkages (n+m) in the polyether carbonate polyol defines the molecular weight of the polyethercarbonate polyol wherein n s 5 and m5, or n10 and m10, or n20 and m20 or n50 and m50, or wherein m+n10, or m+n20, or m+n100.

12. The rigid foam according to claim 1, wherein the polyethercarbonate polyol copolymer utilised has a PDI of from about 1 to less than about 2.

13. The rigid foam according to claim 1, wherein one or more further polyols are present during the reaction with isocyanate or polyisocyanate, and wherein the one or more further polyols form from 0 wt % up to 80 wt % of all the polyols present in the reaction with the isocyanate or polyisocyanate, optionally wherein the one or more further polyols are selected from polycarbonate polyols, polyester polyols, polyether polyols, polymer polyols, polyether-ester carbonate polyols, dendritic polyols, or natural oil polyols.

14. The rigid foam according to claim 1, wherein the rigid foam incorporates a prepolymer.

15. The rigid foam according to claim 1, wherein the flammability according to ASTM D3014 is in the range 40-100% of mass retained.

16. The rigid foam according to claim 1, wherein the rigid foam has a flammability according to ASTM D3014 of less than 20% mass lost, wherein the rigid foam is formed from a reaction mixture comprising the isocyanate or polyisocyanate and the polyethercarbonate polyol copolymer, and wherein the content of the isocyanate or polyisocyanate in the reaction mixture is from 30 wt % to 99 wt %.

17. The rigid foam according to claim 1, wherein the rigid foam has a compression strength in the range 10-700 kPa according to ASTM D1621.

18. The rigid foam according to claim 1, wherein the rigid foam comprises one or more suitable flame retardants, optionally wherein the one or more suitable flame retardants are present in amounts from 0-60 parts of the rigid foam.

19. A polyethercarbonate polyol copolymer derived from the copolymerisation of one or more epoxides with CO.sub.2, wherein the polyethercarbonate polyol copolymer has a functionality of greater than 2 and wherein the total CO.sub.2 content of the polyethercarbonate polyol copolymer is between 10 and 35 wt %, the polyethercarbonate polyol copolymer has m carbonate linkages and n ether linkages, wherein m and n are integers, and m/(n+m) is from 0.2 to 0.7, and the molecular weight of the polyethercarbonate polyol copolymer is less than 1500 g/mol.

20. A polyethercarbonate polyol copolymer derived from the copolymerisation of one or more epoxides with CO.sub.2, wherein the molecular weight of the polyethercarbonate polyol copolymer is less than 1000 g/mol, the polyethercarbonate polyol copolymer has m carbonate linkages and n ether linkages, wherein m and n are integers, and m/(n+m) is from 0.2 to 0.7, and the total CO.sub.2 content is between 20 and 35 wt %.

21. A composition forming one part of a two part composition for producing a rigid foam, said composition comprising a polyethercarbonate polyol copolymer and a blowing agent, wherein the polyethercarbonate polyol copolymer is derived from the copolymerisation of one or more epoxides with CO.sub.2, wherein the total CO.sub.2 content of the polyethercarbonate polyol copolymer is between 1 and 40 wt %, the polyethercarbonate polyol copolymer has m carbonate linkages and n ether linkages, wherein m and n are integers, and m/(n+m) is from 0.2 to 0.7, and the molecular weight of the polyethercarbonate polyol copolymer is between 100 to 5000 g/mol, and wherein the blowing agent is a hydrocarbon optionally selected from the group consisting of: butane, isobutane, 2,3-dimethylbutane, n-pentane, n- and iso-pentane isomers, hexane isomers, heptane isomers, and cycloalkanes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0209] Embodiments of the invention will now be described by way of example only and with reference to the accompanying figures in which:

[0210] FIG. 1 shows the mass retained and extinguish time for a PEC foam according to the invention;

[0211] FIG. 2 shows the mass retained and extinguish time for a further PEC foam according to the invention;

[0212] FIG. 3 shows the Effect of TCPP content on mass retention after burning on rigid foams made with a PEC polyol and an APP benchmark polyol;

[0213] FIG. 4 shows mass retention vs. time during rigid foam sample burning;

[0214] FIG. 5 shows rate of heat emission from rigid foams during burning;

[0215] FIG. 6 shows rate of heat emission vs. time of burning for rigid foam samples produced with PEC and APP benchmark polyols;

[0216] FIG. 7 shows Gas emissions during burning of rigid foams made using a PEC polyol and an APP benchmark polyol;

[0217] FIG. 8 shows the rate of smoke production in burning rigid foam samples made from PEC polyol and APP benchmark polyol;

[0218] FIG. 9 shows mass retention of rigid foams after burning as a function of MDI content of formulation;

[0219] FIG. 10 shows PIR foams formed;

[0220] FIG. 11 shows FT-IR spectrum of PIR foams formed by alternating PPC polyol and random polyethercarbonate polyol;

[0221] FIG. 12 shows rigid foam samples after the Buttler Chimney test;

[0222] FIG. 13 shows rigid foam samples after burning for cone calorimetry;

[0223] FIG. 14 shows the mass retained for rigid foam samples measured on the cone calorimeter;

[0224] FIG. 15 shows the average rate of heat release inside 3 minutes for rigid foam samples measured on the cone calorimeter;

[0225] FIG. 16 shows the fire growth rate for rigid foam samples measured on the cone calorimeter.

[0226] FIG. 17 shows the specific extinction area for rigid foam samples measured on the cone calorimeter;

[0227] FIG. 18 shows the carbon monoxide yield for rigid foam samples measured on the cone calorimeter;

[0228] FIG. 19 shows side on images of rigid foam samples after cone calorimetry testing;

[0229] FIG. 20 shows the viscosity of pentane-polyol mixtures at different addition levels; and

[0230] FIG. 21 shows images of polyol-pentane (100 parts: 10) mixtures.

METHODS

[0231] The following measurements were made according to ASTM standards as described in Table 1.

TABLE-US-00001 TABLE 1 ASTM standards. Test method Result used Description Hydroxyl Value ASTM D4274 Esterification of hydroxyl groups using phthalic anhydride in pyridine. Viscosity ASTM D4878 Multiple shear rates used. Isocyanate index N/A Calculated using isocyanate index and hydroxyl number. Density ASTM D1622 Apparent density measurement. Compression strength ASTM D1621 4 mm cubes compressed in the direction of the foam rise. 4 mm/min crosshead rate Fire retardance by Butler ASTM D3014 Specimens 2 2 cm 25 cm Chimney long burned for 10 s using butane-powered blowtorch. Mass retention and extinguish time measured. Fire retardance by Cone ISO 5660-1 Speciments 10 10 5 cm Calorimetry subjected to a heat flux of 50 kW m.sup.2 and allowed to burn. Various measurements of contribution to fire situation recorded.

Example 1: Polyisocyanurate Rigid Foam Formulations

[0232] Polyethercarbonate polyols were synthesised according to the process described in WO2017/037441A9, with a variety of molecular weights and 002 contents, as described in Table 2.

[0233] The benchmark chosen for comparison was a commercially available aromatic polyester polyol (APP) based on phthalic anhydride and diethylene glycol, with a molecular weight of 350 g/mol. APPs are used in isocyanurate foams due to their enhanced fire retardance when compared to polyether polyols.

TABLE-US-00002 TABLE 2 Relevant information on Polyols CO.sub.2 Hydroxyl content/ Value/ Molecular Viscosity at Polyol name mass % mgKOH/g weight/g/mol 25 C./cP APP benchmark 0 322 350 2200 PEC 1 11.8 153 730 200 PEC 2 14.3 134 840 420 PEC 3 18.8 114 990 1230 PEC 4 23.6 142 790 3200 PEC 5 19.5 167 670 800 PEC 6 19.9 161 700 1150 PPC1 32 204 550 15,500

Polyisocyanurate Foam Formulations

[0234] Polyisocyanurate (PIR) rigid foam formulations were made according to the foam formulation in Table 3, which represents a standard industry formulation for such as foam, with the exception that no flame retardant was added, so the dependence of the flammability of the foam on polyol choice could be more clearly observed. Pentane was chosen as the blowing agent and the levels were kept low for the same reason. A standard mixture of potassium acetate and potassium octanoate were used as trimerization catalysts to ensure isocyanurate formation. Suprasec 5025, a polymeric methylene diisocyanate with a functionality of 2.7 was used as a standard diisocyanate. The same mass of polyol and isocyanate were used for each formulation, but due to the different polyol molecular weights the index was different for each formulation.

[0235] PIR foams were synthesised by the following method:

[0236] Components 4 and 5 (trimerization catalysts) were individually pre-mixed and heated in an oven at 80 C. until homogeneous. These were allowed to cool prior to next step. Components 1-6 were mixed by hand in a beaker until homogeneous. Component 7 (pentane, blowing agent) was added and mixed in by hand until the correct amount was obtained. Without delay, component 8 (polymeric MDI) was added to the mixture and mixed for 10-15 s using an overhead stirrer with paddle blade at 2200 rpm. Without delay, this mixture was poured into a lined tray which was pre-heated to 80 C. The dimensions of the tray were 25256 cm. The foam was allowed to free-rise. Rise time, gelation time and tack-free time were measured and within 2-3 minutes for all formulations.

TABLE-US-00003 TABLE 3 Polyisocyanurate foam formulation. Component Mass/% 1 Polyol 30.64 2 Water 0.10 3 Surfactant: Struksilon 8032 0.52 4 Potassium acetate 15% in DEG 0.42 5 Potassium octanoate 15% in DEG 2.54 6 1,1,4,7,7-pentamethylene diethylene triamine 0.05 7 n-pentane 2.50 8 Polymeric MDI: Suprasec 5025 63.23 Total 100.00

Results

TABLE-US-00004 TABLE 4 Results. Compression Mass Exper- Isocyanate Density/kg strength/ retained on iment Polyol index/% m.sup.3 MPa burning/% 1 PEC 1 330 54.2 0.311 61.2 2 PEC 2 355 62.4 0.378 67.2 3 PEC 3 389 56.1 0.376 56.9 4 PEC 4 348 65.5 0.452 61.7 5 APP 200 46.6 0.311 47.4 benchmark

[0237] FIG. 1 demonstrates the improved flammability performance. It can also be seen from Table 4, PEC based PIR foams provided an increase of 10-15% mass retention when compared to the APP benchmark. The charring effect was greater when PEC polyols were used, and the fire was not able to penetrate the foam as easily. In the absence of a flame-retardant, the presence of CO.sub.2 in the polyols reduced the flammability of PIR foam significantly versus the aromatic benchmark. The improvement vs. aliphatic polyether polyols is therefore even more dramatic, even at relatively low CO.sub.2 contents.

Example 2: Polyisocyanurate Rigid Foam Formulations with Higher MDI Content

[0238] Example 1 was repeated, except the formulation was changed to alter the MDI content.

TABLE-US-00005 TABLE 5 Polyisocyanurate foam formulation. Component Mass/% 1 Polyol 19.74 2 Water 0.12 3 Surfactant: Struksilon 8032 0.60 4 Potassium acetate 15% in DEG 0.49 5 Potassium octanoate 15% in DEG 2.96 6 1,1,4,7,7-pentamethylene diethylene triamine 0.06 7 n-pentane 2.50 8 Polymeric MDI: Suprasec 5025 73.52 Total 100.00

Results

TABLE-US-00006 TABLE 6 Results. Compression Mass Exper- Isocyanate Density/kg strength/ retained on iment Polyol index/% m.sup.3 MPa burning/% 1 PEC 1 446 49.4 0.304 81.6 2 PEC 2 474 61.6 0.417 84.9 3 PEC 3 502 59.0 0.434 79.0 4 PEC 4 463 63.6 0.477 78.3 5 APP 300 58.6 0.534 73.1 benchmark

[0239] FIG. 2 demonstrates the improved flammability performance. It can also be seen from Table 6, PEC based PIR foams provided an increase of 5-10% mass retention when compared to the APP benchmark. Due to the higher isocyanate content than the previous example, the values of mass retained are all of higher value than previously. The charring effect was greater when PEC polyols were used, and the fire was not able to penetrate the foam as easily. In the absence of a flame-retardant, the presence of CO.sub.2 in the polyols reduced the flammability of PIR foam significantly versus the aromatic benchmark.

Example 3: Polyisocyanurate Rigid Foam Formulations Containing TCPP Flame Retardant Additive

[0240] Further examples were produced with varying addition levels of the flame retardant additive Tris(1,3-dichloro-2-propyl)phosphate to demonstrate the differing performance of the PEC polyols vs. the APP benchmark polyol.

TABLE-US-00007 TABLE 7 Polyisocyanurate foam formulation. Component Mass/% 1 Polyol 30.00 2 Water 0.10 3 Surfactant: Struksilon 8032 0.64 4 Potassium acetate 15% in DEG 0.42 5 Potassium octanoate 15% in DEG 2.54 6 1,1,4,7,7-pentamethylene diethylene triamine 0.06 7 n-pentane 4.00 8 Polymeric MDI: Suprasec 5025 62.24 9 Tris(1,3-dichloro-2-propyl)phosphate 0.75-3.00 variable Total 100.75-103.00

Results

TABLE-US-00008 TABLE 8 Results. Mass retained Isocyanate TCPP Compression on index/ content/ Density/ strength/ burning/ Expt Polyol % % kg m.sup.3 MPa % 1 PEC 5 313 0.75 36.9 0.177 75.6 2 PEC 6 319 0.75 42.6 0.230 80.2 3 APP 200 0.75 36.7 0.274 68.1 benchmark 4 PEC 5 313 1.50 81.0 5 APP 200 1.50 37.5 0.264 81.4 benchmark 6 PEC 5 313 3.00 36.9 0.182 88.7 7 APP 200 3.00 37.8 0.268 87.4 benchmark

[0241] The formulations were made with 0.75, 1.5 and 3 wt % TCPP with the same isocyanate content in the formulations. Table 8 and FIG. 3 show comparison of the flammability at 1.5 and 3.0 wt % TCPP demonstrates the performance is roughly equivalent for both the APP benchmark formulations and the PEC polyols, which demonstrates that in these formulations the flammability is governed by the isocyanate content and flame retardant contentthat is the polyol choice makes little difference to the flammability of these specific formulations. However, when the flame retardant content is decreased to 0.75 wt % both PEC5 and PEC6 (formulations 1 & 2) demonstrating similar mass retention to the formulations with 1.5 wt % TCPP. The APP benchmark (formulation 3) shows significant degradation in its flammability performance with reduced flame retardant content. FIG. 11 shows the samples burnt in the Buttler Chimney test for formulations 2 (bottom) & 3 (top), which visually demonstrate the decreased flammability of the rigid foam formulations using PEC polyols. This demonstrates that PEC polyols can be used to reduce flame retardant loadings whilst keeping similar flammability performance, which is a benefit for cost and environmental reasons.

TABLE-US-00009 TABLE 9 Results of cone calorimetry experiment. Benchmark PEC 6 (3) (2) Time to ignition/s 1 1 Test duration/s 255 407 Mass loss/% 63 44 Mass retained/% 37 56 Peak rate of heat release/kW m.sup.2 278.6 231.2 Total heat released/MJ m.sup.2 32.9 31.5 Fire performance index/m.sup.2s kW.sup.1 0.004 0.004 Smoke parameter/MW kg.sup.1 187.18 79.83 Maximum average rate of heat 191.17 133.56 emission/kW m.sup.2 Fire growth rate/W s.sup.1 5791.7 4294.1 Average rate of heat release within 3 155.3 107.8 min/kW m.sup.2 Average rate of heat release within 5 89.4 min/kW m.sup.2 Effective heat of combustion/MJ kg.sup.1 27.6 32.62 Specific Extinction Area/m.sup.2 kg.sup.1 671.87 345.29 CO Yield/kg kg.sup.1 0.0521 0.0282 CO.sub.2 Yield/kg kg.sup.1 0.06 0

[0242] Formulations 2 & 3 were subjected to cone calorimetry tests to further demonstrate the improved flammability performance of the PEC polyols, the results are summarised in table 9. FIG. 4 demonstrates that once more, the PEC polyol demonstrated a higher mass retention in comparison to the APP benchmark. The rate of heat release and the total heat released were also less when the PEC polyol was used (see FIGS. 5 & 6. Furthermore, the levels of smoke were significantly reduced when the PEC polyols was used (see FIG. 8) and the emissions of both CO and CO.sub.2 were dramatically reduced (see FIG. 7). These factors demonstrate that the PEC-containing foam would contribute less to the propagation of a fire in a developed fire situation and would emit a smaller amount of smoke and toxic fumes in a fire situation than the APP benchmark polyol.

Example 4Formulations with Further Reduced MDI Content

[0243] Further formulations were developed with a reduced isocyanate content, to demonstrate the improved flammability performance of the PEC polyols, even at reduced isocyanate content. Whilst the aromatic isocyanates benefit the flammability performance of rigid foams, it is beneficial to reduce the isocyanate content from a cost perspective.

TABLE-US-00010 TABLE 10 Formulations with reduced isocyanate content Component Mass/% 1 Polyol 29.09 33.74 38.23 2 Water 0.10 0.11 0.13 3 Surfactant: Struksilon 8032 0.62 0.72 0.82 4 Potassium acetate 15% in DEG 0.41 0.47 0.54 5 Potassium octanoate 15% in DEG 2.46 2.86 3.24 6 1,1,4,7,7-pentamethylene diethylene triamine 0.06 0.07 0.08 7 n-pentane 4.00 4.00 4.00 8 Polymeric MDI: Suprasec 5025 60.36 55.11 50.08 9 Tris(1,3-dichloro-2-propyl)phosphate 2.91 2.91 2.91 Total 100.00 100.00 100.00

[0244] Three different formulations with isocyanate indexes of 60, 55 and 50 were used with both PEC polyols and the benchmark polyols.

TABLE-US-00011 TABLE 11 Results from formulations with reduced isocyanate contents Mass retained MDI Compression on Isocyanate content/ Density/ strength/ burning/ Expt Polyol index/% % kg m.sup.3 MPa % 1 PEC 5 313 60 36.9 0.182 88.7 2 APP 200 60 37.8 0.268 87.4 benchmark 3 PEC 6 252 55 34.7 0.160 89.3 4 APP 158 55 37.4 0.224 72.0 benchmark 5 PEC 6 202 50 35.8 0.109 59.6 6 APP 127 50 41.6 0.214 62.8 benchmark

[0245] Table 11 and FIG. 9 show the flammability results of these formulations. At an isocyanate content of 60%, the PEC polyol (formulation 1) delivers a marginal improvement in flammability performance on the APP benchmark (formulation 2). Once the MDI content is reduced to 55%, the PEC polyol (formulation 3) retains the same flammability performance and a similar density and compression strength to formulation 1. However, at 55% isocyanate content formulation 4, using the APP benchmark, shows a 15% decrease in mass retained on burning. This demonstrates that the same flammability performance can be gained using PEC polyols with a 5% reduction in isocyanate content compared to the benchmark polyol. If the isocyanate content is reduced to 50%, both foams have significantly reduced flame retardance. At this index, the foams are expected to be predominantly polyurethane foams without significant trimerization and so would not be expected to have good flammability performance.

Example 5PIR Foam Formulations with an Alternating Polycarbonate Polyol

[0246] A comparative PIR formulation was attempted using an alternating polycarbonate diol, PPC-1. The formulation was very similar to those used for PEC polyols in example 1, with an index of 300.

TABLE-US-00012 TABLE 12 PPC-1 PIR foam formulation. Component Mass/% 1 Polyol 28.95 2 Water 0.12 3 Surfactant: Struksilon 8032 0.58 4 Potassium acetate 15% in DEG 0.35 5 Potassium octanoate 15% in DEG 2.43 6 1,1,4,7,7-pentamethylene diethylene triamine 0.06 7 n-pentane 2.50 8 Polymeric MDI: Suprasec 5025 65.03 Total 100.00

[0247] PPC-1 has a viscosity of 15,500 cP at 25 C. (see table 2), approximately seven times higher than the APP benchmark, and five times higher than PEC-4 which contains 10% less CO.sub.2. This made it considerably harder to mix in the rigid foam formulation, which was very viscous.

[0248] A large exotherm was observed in the centre of the foam during formation, with the internal temperature peaking at 134 C., causing the foam to split during rise (see FIG. 10). In comparison the internal temperature of the foam made using PEC-4 only reached 103 C. during foam formation. Similar foams made using polypropylene glycol (PPG) polyols have shown internal temperatures around 100 C., indicating the PEC foam formation proceeded as expected.

[0249] An FT-IR spectrum was taken of the PIR foam made using PPC-1 and also of a foam made using PEC-4. FIG. 11 shows the foam made using PPC-1 contains a significant quantity of cyclic propylene carbonate, as observed by the strong band at 1790 cm.sup.1. PPC-1 did not contain any significant traces of cyclic propylene carbonate (<0.5 wt %), thus the cyclic propylene carbonate must have been formed as a degradation product of the PPC polyol during the foaming formation. This is most probably due to the combined sensitivity of PPC polyols to basic catalysts (such as the potassium acetate, potassium octanoate and amine catalysts used in PIR formation), and to temperature. In comparison, the foam made with random PEC-4 doesn't show any propylene carbonate formation in the IR spectrum, indicating the polyol is stable to both the basic catalysts and temperature and forms a foam correctly.

[0250] The results demonstrate that, unlike highly alternating PPC polyols, random polyethercarbonate polyols can be made to have similar (or lower) viscosities to the benchmark polyol, enabling easy processing and their use without the need for blending with other polyols. They also exhibit stability to both basic catalysts and elevated temperature during the foaming process, allowing controlled foam formation, while the alternating PPC polyol is not stable under these conditions. The larger exotherm observed during PPC foaming is thought to be due to the PPC polyol degradation process, or due to the formation of hotspots caused by the extremely high viscosity of the mixture.

[0251] It was not possible to measure any meaningful performance data from the foam produced by PPC-1 as the foam did not form correctly and the mechanical integrity was compromised.

Example 6Cone Calorimetry of the Formulations of Examples 3 and 4

[0252] Cone calorimetry was used to further exemplify the results in examples 3 and 4. Only selected formulations were carried forwardthe reduced TCPP version at 0.75%; and the reduced MDI version at 55%, alongside a full fire-resistant formulation. The formulations are listed in table 13:

TABLE-US-00013 TABLE 13 Polyisocyanurate foam formulations. Mass/% Reduced Reduced Component Full FR TCPP MDI 1 Polyol 29.09 30.00 33.74 2 Water 0.10 0.10 0.11 3 Surfactant: Struksilon 8032 0.62 0.64 0.72 4 Potassium acetate 15% in DEG 0.41 0.42 0.47 5 Potassium octanoate 15% in DEG 2.46 2.54 2.86 6 1,1,4,7,7-pentamethylene diethylene 0.06 0.06 0.07 triamine 7 n-pentane 4.00 4.00 4.00 8 Polymeric MDI Suprasec 5025 60.36 62.24 55.11 9 Tris(1,3-dichloro-2-propyl)phosphate 2.91 0.75 2.91 Total 100.00 100.75 100.00

[0253] A second APP benchmark was added to the experiment. The hydroxyl value of this benchmark was 240 mgKOH g.sup.1.

[0254] The results are shown in table 14:

TABLE-US-00014 TABLE 14 Results. Mass Isocy- Com- retained anate TCPP MDI pression on index/ content/ content/ Density/ strength/ burning/ Expt Polyol % % % kg m.sup.3 MPa % 1 APP 1 200 3 60 37.8 0.268 87.4 2 APP 2 247 3 60 40.4 0.357 93.2 3 PEC 313 3 60 36.9 0.182 88.7 4 APP 1 200 0.75 60 36.7 0.274 68.1 5 APP 2 247 0.75 60 40.1 0.322 81.8 6 PEC 313 0.75 60 36.9 0.177 80.2 7 APP 1 158 3 55 37.4 0.224 72.0 8 APP 2 195 3 55 38.1 0.277 87.6 9 PEC 252 3 55 34.7 0.160 89.3

[0255] The following conclusions are drawn from the results of the cone calorimetry experiment (see Table 15). In a fully fire resistant formulation, the performance is good for all three of the polyols used. However, when the TCPP additive and MDI quantity were reduced, only the PEC based foam was able to maintain its high performance, with the two APP benchmarks losing performance in varying amounts (APP 2 being superior to APP 1).

[0256] The PEC based foams demonstrated greater mass retention than the benchmarks when the additive levels were reduced, demonstrating the foams to be more fire resistant (see FIG. 14). They also showed lower rates of heat emission and fire growth rates than the benchmarks, meaning they contribute less to the growth of a fire than the APP examples (see FIGS. 15 and 16). Vast reductions in smoke (specific emission) and carbon monoxide emissions were found when compared to the benchmarks, even in the highly fire-resistant formulations, indicating they can decrease the risks of smoke inhalation during a fire (see FIGS. 17 and 18).

[0257] Side on images of samples after cone calorimetry testing are shown in FIG. 19 for APP 1, Full FR (top left), APP 1, reduced MDI (top right), and PEC Full FR (bottom left) and PEC reduced MDI (bottom right). These images demonstrate enhanced resistance to the burn through of the sample in the PEC based foam.

[0258] A further benefit of PEC over APP was observed when blending the formulations. The blowing agent n-pentane was added and stirred in by hand. This process was visibly easier with PEC when compared to APP. This was verified by mixing varying amounts of pentane with 100 parts polyol and measuring the viscosity (see FIG. 20). The viscosity was observed to decrease when PEC was mixed with pentane, indicating good miscibility. The same was not observed with either APP benchmark.

[0259] FIG. 21 shows still images of polyol-pentane (100 parts: 10) mixtures. The PEC sample (shown in the rear) shows much better flow and a clear liquid, indicating good miscibility when compared to the APP sample (shown in the front).

Example 7: Synthesis of Polyols with Functionality >2

[0260] Polyols were synthesised as per the teaching of WO2017/037441A9

Synthesis of PEC 7:

[0261] 17.2 mg of a DMC catalyst according to example 1 of WO2018/158370A1 was taken into a 100 mL reactor along with hexanediol (4.8 g) and trimethylolpropane ethoxylate 450 (TMPEO-450) (3.0 g). The mixture was dried at 120 C. under vacuum for 1 hour. Catalyst 2 of WO2017/037441A9 (172 mg) was dissolved in PO (50 mL) and injected into the vessel. The vessel was heated to the desired temperature (73 C.) for 4 hours at 10 bar. The temperature was then raised to 85 C. After reaction completion, the reactor was cooled to below 10 C. and the pressure was released. NMR and GPC were measured immediately.

Synthesis of PEC 8:

[0262] Synthesis was carried out according to PEC 7 except with hexanediol (5.3 g) and TMPEO-450 (3.3 g).

Synthesis of PEC 9:

[0263] Synthesis was carried out according to PEC 7 except with hexanediol (5.3 g) and TMPEO-450 (3.3 g).

Synthesis of PEC 10:

[0264] Synthesis was carried out according to PEC 7 except on a 2 L reactor using the following quantities: 206 mg of DMC catalyst, hexanediol (18 g), TMPEO-450 (68 g), EtOAc (240 g), Catalyst 2 of WO2017/037441A9 (2.06 g) and PO (498 g)

Synthesis of PEC 11:

[0265] Synthesis was carried out according to PEC 10, except at 5 bar pressure.

TABLE-US-00015 TABLE 15 Results of cone calorimetry experiments. Experiment number 1 2 3 4 5 6 7 8 9 Time to ignition/s 1 1 1 1 1 1 1 1 1 Test duration/s 343 597 402 255 445 407 355 494 293 Mass loss/% 43 35 43 63 58 44 62 49 43 Mass retained/% 57 65 57 37 42 56 38 51 57 Peak rate of heat 203.1 166.5 193.7 278.6 236.6 231.2 223.8 205.3 188 release/kW m.sup.2 Total heat released/ 24.9 21.7 25.9 32.9 40.7 31.5 30.2 29.4 19.8 MJ m.sup.2 Fire performance 0.005 0.006 0.005 0.004 0.004 0.004 0.004 0.005 0.005 index/m.sup.2s kW.sup.1 Smoke parameter/ 87.62 61.92 43.85 187.18 149.55 79.83 124.65 68.11 42.44 MW kg.sup.1 Maximum average 135.22 92.51 124.12 191.17 158.5 133.56 164.46 126.04 123.54 rate of heat emission/ kW m.sup.2 Fire growth rate/W s.sup.1 4366.6 3037.5 4022.1 5791.7 5064.1 4294.1 5187.9 4135.1 4012.7 Average rate of heat 96.3 55.1 93.3 155.3 130.4 107.8 118.9 92.3 88.2 release within 3 min/kW m.sup.2 Average rate of heat 77.6 47.9 75.7 113.5 89.4 95.6 75.6 release within 5 min/kW m.sup.2 Effective heat of 28.2 28.6 27.89 27.6 30.99 32.62 23.76 30.23 23.53 combustion/MJ kg.sup.1 Specific Extinction 431.42 371.88 226.39 671.87 632.09 345.29 556.99 331.78 225.72 Area/m.sup.2 kg.sup.1 CO Yield/kg kg.sup.1 0.0445 0.134 0.0299 0.0521 0.042 0.0282 0.0575 0.0533 0.0241 CO.sub.2 Yield/kg kg.sup.1 0.27 0 0.28 0.06 0 0 0.87 0 0.6

Synthesis of PEC 12:

[0266] Synthesis was carried out according to PEC 11, except using 57.8 g hexanediol and 36.3 g TMPEO-450

Synthesis of PEC 13:

[0267] Synthesis was carried out according to PEC 11, except using 63.6 g hexanediol and 39.9 g TMPEO-450, at 10 bar pressure.

Synthesis of PEC 14:

[0268] Synthesis was carried out according to PEC 10, except with 118 g hexanediol and no TMP-EO-450 at 10 bar pressure.

TABLE-US-00016 TABLE 16 Low molecular weight polyols with >2 functionality CO.sub.2 wt Mn-GPC Mn- PEC Functionality % (g/mol) PDI OH Value OHv 7 2.2 17.1 1050 1.19 8 2.2 14.5 940 1.18 9 2.2 14.2 840 1.17 10 2.5 26.9 1900 1.55 71.7 1955 11 2.5 20.1 1800 1.48 70.2 2002 12 2.2 17.0 1030 1.17 123.9 996 13 2.2 16.1 910 1.19 137.9 895 14 2.0 25.0 620 1.14 167.4 670

[0269] PEC Examples 7-14 demonstrate the synthesis of low molecular weight polyols containing a range of functionalities and CO.sub.2 contents as produced by this method. Polyols with increased functionality are particularly useful in PIR and PUR rigid foam formulations as they increase the cross-linking ability of the polyol.

Example 8: Spray Polyurethane (PUR) Rigid Foam Formulation Made from Polyethercarbonate Polyols

[0270] A rigid polyurethane spray foam system was formulated using polyethercarbonate polyols. The polyols used are shown in table 17:

TABLE-US-00017 TABLE 17 Polyols used in spray foam formulations Hydroxyl CO.sub.2 Value/ Molecular Viscosity at Polyol name content/mass % mgKOH/g weight/g/mol 25 C./cP APP 0 322 350 2200 benchmark APP 0 235 480 2400 benchmark 2 PEC 15 17.6 157 715 782 PEC 14 25.0 167.4 670 2900 Propoxylated 0 490 515 6050 sorbitol polyol Mannich base 0 450 623 5550 polyol

[0271] The spray foam formulations used are shown in table 18:

TABLE-US-00018 TABLE 18 Spray foam formulations Component Mass/% 1 APP or PEC polyol 16.40 2 Propoxylated sorbitol polyol 5.00 3 Mannich base polyol 21.62 4 Surfactant: Struksilon 8032 0.60 5 Water 0.70 6 Potassium octanoate 15% in DEG 0.50 7 Triethylene diamine 33% in DEG (LV 33) 0.13 8 Tibkat 214 tin catalyst 0.05 9 Solstice LBA 5.00 10 Tris(1,3-dichloro-2-propyl)phosphate 5.00 11 Lupranat M20S PMDI 50 Total 105

[0272] The four foams made from these formulations had densities in the range 37.9-40.6 kg m.sup.3. This exemplifies the use of PEC polyols in PUR foams in addition to PIR foams. All foams had a cure time of 45-50 s.

Example 9: Polyisocyanurate Foam Formulation Made from Polyethercarbonate Polyols with Functionality Greater than 2

[0273] The polyols used are shown in table 19:

TABLE-US-00019 TABLE 19 Polyol with functionality >2 used in PIR foam formulations CO.sub.2 Hydroxyl Molecular Viscosity Polyol content/ Value/ Functionality/ weight/ at name mass % mgKOH/g eq./mol g/mol 25 C./cP PEC 13 16.1 138 2.2 895 NM

[0274] The formulation outlined in table 13 (full FR) was successfully used to make the PIR foam using PEC 13. The foam had a tack-free time of 100 s.

Example 10: Polyisocyanurate Foam Made from Combination of Polyethercarbonate and Other Polyols

[0275] PEC 15 was used in conjunction with other polyols according to the following formulations.

TABLE-US-00020 TABLE 20 Formulations for PIR foams using polyol blends Mass/% Component A B C D E 1 PEC Polyol 21.09 27.63 26.93 29.09 29.09 2 Mannich base polyol 8.00 3 Glycerol 1.45 4 Trimethylolpropane 215 3 Water 0.10 0.10 0.10 0.10 0.10 4 Surfactant: Struksilon 0.62 0.62 0.62 0.62 0.62 8032 5 Potassium acetate 0.41 0.41 0.41 0.41 0.41 15% in DEG 6 Potassium octanoate 2.46 2.46 2.46 2.46 2.46 15% in DEG 7 1,1,4,7,7- 0.06 0.06 0.06 0.06 0.06 pentamethylene diethylene triamine 8 n-pentane 4.00 4.00 4.00 4.00 4.00 9 Polymeric MDI: 60.36 60.36 60.36 60.36 60.36 Suprasec 5025 10 Tris(1-chloro-2- 2.91 2.91 2.91 2.91 2.91 propyl)phosphate Total 100.00 Cure time (80 C. 52 90 mould) Cure time (unheated 70 120 300 mould)

[0276] The PEC was used in the above formulation to successfully make a PIR foam, demonstrating a blend of polyols can be used should it be desired for the final application. The blend of polyols had a hydroxyl value of 240. This enables the formulator to select the isocyanate index according to what blend of polyols is used, in addition the cure speed can be controlled both with and without the use of a heated mould.

Example 11: Polyisocyanurate Foams Made from Combination of Polyether Carbonate Polyols and Aromatic Polyester Polyols

[0277] PIR foams were made using blends of polyethercarbonate polyol and APP benchmark polyols. The formulations are shown in table 21:

TABLE-US-00021 TABLE 21 formulations of PIR foams using blends of PEC polyols and APP benchmarks. Component Mass/% 1 PEC 15 14.54 2 APP 2 14.55 3 Water 0.10 4 Surfactant Struksilon 8032 0.62 5 Potassium acetate 15% in DEG 0.41 6 Potassium octanoate 15% in DEG 2.46 7 1,1,4,7,7-pentamethylene diethylene triamine 0.06 8 n-pentane 4.00 9 Polymeric MDI: Suprasec 5025 60.36 10 Tris(1-chloro-2-propyl)phosphate 2.91 Total 100.00

[0278] The foam made from the formulation above showed physical properties which demonstrates that PEC polyols can be used alongside APP polyols if this was to be desired.

Example 12: Performance Improvements of Rigid Foams Catalysed by Bismuth Catalysts

[0279] Bismuth neodecanoate was employed in order to enhance the cure speed of the PIR foam based on PEC polyol, which contains a substantial amount of secondary hydroxyls. As such, performance enhancements in lower thermal conductivity (lambda) and higher compression strength were observed.

TABLE-US-00022 TABLE 22 Formulations of PIR foams using bismuth neodecanoate as added catalyst Mass/% Component A B C 1 PEC 15 29.09 29.09 2 APP 2 29.09 3 Water 0.10 0.10 0.10 4 Surfactant Struksilon 8032 0.62 0.62 0.62 5 Potassium acetate 15% in DEG 0.41 0.41 0.41 6 Potassium octanoate 15% in DEG 2.46 2.46 2.46 7 1,1,4,7,7-pentamethylene diethylene 0.06 0.06 0.06 triamine 8 n-pentane 4.00 4.00 4.00 9 Bismuth neodecanoate 0.35 10 Polymeric MDI: Suprasec 5025 60.36 60.36 60.36 11 Tris(1-chloro-2-propyl)phosphate 2.91 2.91 2.91 Total 100.00 100.00 100.00 Cure time (80 C. mould) 90 70 65 Free-rise density (kg m.sup.3) 34.7 40.4 38.1 Compression strength (kPa) 160 231 277 Thermal conductivity (mW m.sup.1 27.4 24 24.5 K.sup.1)

[0280] This exemplifies that the reaction speed of PEC polyol in PIR foam can be altered with use of selected catalysts in order to provide the desired foam formation properties and subsequent physical properties of the foam, as desired by the formulator.

[0281] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0282] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0283] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0284] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.