POLY(ARYLENE SULFIDE) COPOLYMER

Abstract

The present invention relates to a poly(arylene sulfide) (PAS) copolymer (P) comprising: at least one block of poly(arylene sulfide) (PAS) having a weight-average molecular weight (Mw) of at least 40,000 g/mol as determined by gel permeation chromatography, and at least one block of polyorganosiloxane (POS) having a weight-average molecular weight (Mw) of at most 5,000 g/mol as determined by gel permeation chromatography, wherein the weight ratio of PAS:POS is from 95:5 to 99.5:0.5.

Claims

1. A poly(arylene sulfide) (PAS) copolymer (P) comprising: at least one block of poly(arylene sulfide) (PAS) having a weight-average molecular weight (Mw) of at least 40,000 g/mol as determined by gel permeation chromatography; and at least one block of polyorganosiloxane (POS) having a weight-average molecular weight (Mw) of at most 5,000 g/mol as determined by gel permeation chromatography; wherein the weight ratio of PAS:POS is from 95:5 to 99.5:0.5.

2. The PAS copolymer (P) of claim 1, comprising at least 1 ppm (wt) content of a polymer-bonded chlorine, based on the total weight of the PAS copolymer (P), as determined by means of X-ray Fluorescence (XRF) analysis calibrated with standards of known chlorine content as determined via Combustion and Ion Chromatography according to BS EN 14582.

3. The PAS copolymer (P) of claim 1, wherein the at least one block of PAS comprises at least 50 mol. % of a recurring PAS unit (R.sub.PAS) according to formula (I), based on the total number of moles of recurring units in the block of PAS: ##STR00006## wherein R is independently selected from the group consisting of halogen atoms, C1-C12 alkyl groups, C7-C24 alkylaryl groups, C7-C24 aralkyl groups, C6-C24 arylene groups, C1-C12 alkoxy groups, and C6-C18 aryloxy groups, and i is independently zero or an integer from 1 to 4.

4. The PAS copolymer (P) of claim 1, wherein the at least one block of the PAS has a calcium content of less than 200 ppm, as measured by X-ray Fluorescence (XRF) analysis calibrated with standards of known calcium content as determined via ICP-OES according to ASTM UOP714-07.

5. The PAS copolymer (P) of claim 1, wherein the at least one block of POS is according to formula (II): ##STR00007## wherein: R.sub.1, R.sub.2 and R.sub.3 and R.sub.4, equal to or different from each other, are selected from C.sub.1-C.sub.10 alkyl groups and C.sub.6-C.sub.10 aromatic groups; n varies between 2 and 70; and p is zero or 1.

6. The PAS copolymer (P) of claim 1, wherein R.sub.1 and R.sub.2 are methyl groups, R.sub.3 is a propylene group, p is 1 and R.sub.4 is a methylene group.

7. The PAS copolymer (P) of claim 1, wherein the weight-average molecular weight (Mw) of the PAS copolymer (P) ranges from 40,000 g/mol to 120,000 g/mol.

8. The PAS copolymer (P) of claim 1, wherein the melting point (T.sub.m) of the PAS copolymer (P) is of at least 230° C., when determined on the 2.sup.nd heat scan in differential scanning calorimeter (DSC) according to ASTM D3418, using heating and cooling rates of 20° C./min.

9. The PAS copolymer (P) of claim 1, wherein the glass transition temperature (T.sub.g) of the PAS copolymer (P) is of at least 50° C., when determined on the 2.sup.nd heat scan in differential scanning calorimeter (DSC) according to ASTM D3418, using heating and cooling rates of 20° C./min.

10. A process for preparing a poly(arylene sulfide) (PAS) copolymer (P) comprising blending at a temperature of at least T.sub.m+10° C. a reaction mixture comprising: at least one poly(arylene sulfide) (PAS) polymer having a weight-average molecular weight (Mw) of at least 40,000 g/mol as determined by gel permeation chromatography; and at least one polyorganosiloxane (POS) macromer having epoxy groups at each end of its chain and having a weight-average molecular weight (Mw) of at most 5,000 g/mol as determined by gel permeation chromatography, wherein: T.sub.m is the melting point of the reaction mixture; the weight ratio between the PAS polymer and the POS macromer is from 95:5 to 99.5:0.5; and the process is carried out in the absence of an added solvent or in the presence of an amount of less than 2 wt. % of the added solvent based on the total weight of the reaction mixture.

11. The process of claim 10, wherein the PAS polymer comprises at least one functional group at at least one of its chain ends and the functional groups are according to formula (IV): ##STR00008## wherein Z is selected from the group consisting of halogen atoms, carboxyl group, amino group, hydroxyl group, thiol group, acid anhydride group, isocyanate group, amide group, and derivatives thereof.

12. The process of claim 10, wherein the POS macromer is according to formula (VI): ##STR00009## wherein: Q is an epoxy group; R.sub.1, R.sub.2 and R.sub.3 and R.sub.4, equal to or different from each other, are selected from C.sub.1-C.sub.10 alkyl groups and C.sub.6-C.sub.10 aromatic groups; n varies between 2 and 70; and p is zero or 1.

13. A composition (C) comprising: the poly(arylene sulfide) (PAS) copolymer (P) of claim 1; and up to 60 wt. % of at least one filler, based on the total weight of the composition (C).

14. An article, part or composite material comprising the poly(arylene sulfide) (PAS) copolymer (P) of claim 1 or a composition (C) comprising the poly(arylene sulfide) (PAS) and up to 60 wt % of at least one filler.

15. A method of manufacturing a three-dimensional (3D) object comprising: depositing the poly(arylene sulfide) (PAS) copolymer (P) of claim 1 or a composition (C) comprising the poly(arylene sulfide) (PAS) and up to 60 wt % of at least one filler via additive manufacturing.

Description

EXPERIMENTAL SECTION

[0139] Materials

[0140] Ryton® QA200N is a poly(phenylene sulfide) commercially available from Solvay Specialty Polymers USA, LLC.

[0141] Ryton® QA321N is a poly(phenylene sulfide) commercially available from Solvay Specialty Polymers USA, LLC.

[0142] DMS-E12 is an epoxypropoxypropyl terminated PDMS macromer (Mw 1,200 g/mol) commercially available from Gelest Inc. DMS-E12 will be referred to below as Ep-PDMS 1200.

[0143] DMS-E21 is an epoxypropoxypropyl terminated PDMS macromer (Mw 5,000 g/mol) commercially available from Gelest Inc. DMS-E21 will be referred to below as Ep-PDMS 5000.

[0144] Methods

[0145] DSC/Heat of Fusion

[0146] DSC analyses were carried out on a TA Q20 Differential Scanning calorimeter according to ASTM D3418 and data was collected through a two heat-one cool method. The protocol used is the following: 1.sup.st heat cycle from 30.00° C. to 350.00° C. at 20.00° C./min; isothermal for 5 minutes; 1.sup.st cool cycle from 350.00° C. to 100.00° C. at 20.00° C./min; 2.sup.nd heat cycle from 100.00° C. to 350.00° C. at 20.00° C./min. The melting temperature (T.sub.m) is recorded during the 2.sup.nd heat cycle and the melt crystallization temperature (T.sub.mc) is recorded during the cool cycle.

[0147] GPC

[0148] The weight-average molecular weight (Mw) of the poly(phenylene sulfide) copolymers was determined by gel permeation chromatography (GPC) at 210° C. using a PL 220 high temperature GPC with a 1-chloronaphtalene mobile phase.

[0149] Mechanical Testing

[0150] Test specimens according to Examples 1 to 3 (E1 to E3) and Comparative Examples 5 and 6 (CE5, CE6) were injection molded into Type V tensile bars according to ASTM D3641 (using a barrel temperature set at T.sub.m+30° C. in a mold regulated at 130° C.) and tested at ambient temperature according to ASTM D638 at a speed of 0.05 in/min.

[0151] Test specimens according to Example 7 (E7) and Comparative Example 9 (CE9) were injection molded into ISO bars on a Toshiba ISG 150 Injection Molder and tested at ambient temperature according to ISO 527-2 at a speed of 1 mm/min.

[0152] The ISO bar of Example 7 (E7) was also subjected to fracture toughness testing according to ASTM 5045. Force and displacement, applied through a Zwick tensile strain machine at a speed of 1 mm/min, were recorded and toughness was evaluated according to ASTM 5045.

Synthesis Examples

[0153] Poly(phenylene sulfide) copolymers according to Examples 1 to 3 (E1 to E3), Comparative Examples 4 to 6 (CE4 to CE6), Example 7 (E7) and Comparative Examples 8 to 10 (CE8 to CE10) were obtained from corresponding reactive blends containing a poly(phenylene sulfide) selected from Ryton® QA200N and Ryton® QA321N and an epoxypropoxypropyl terminated PDMS macromer selected from Ep-PDMS 1200 and Ep-PDMS 5000. Tables 1 and 2 below show the compositions of the reactive blends as well as the weight-average molecular weight (Mw) of the respective copolymers.

[0154] The reactive blends shown in Table 1 were made in a DSM Xplore Micro-compounder equipped with a Micro Injection Molding Machine 10 cc. The processing conditions used for making the blends are the following:

[0155] Recirculation time=15 minutes;

[0156] DSM speed=200 rpm;

[0157] Temperature=340° C.;

[0158] Target melt temperature=320° C.

TABLE-US-00001 TABLE 1 Ryton ® Ryton ® Ep-PDMS Ep-PDMS QA200N QA321N 1200 5000 Mw [wt. %] [wt. %] [wt. %] [wt. %] [g/mol] E1 99.4 — 0.6 — 62,600 E2 98.4 — 1.6 — 61,800 E3 97.5 — — 2.5 74,800 CE4 93.6 — — 6.4 61,600 CE5 — 98.8 1.2 — n/a CE6 — 96.9 3.1 — n/a

[0159] The reactive blends shown in Table 2 were made by blending the components in a Coperion ZSK-26 twin screw extruder, which is provided with 12 barrel zones and a heated exit die operating at up to 450° and is capable of mass throughputs higher than 30 kg/hour.

[0160] The components were initially mixed in a plastic bucket and sealed. The bucket was placed on a vibratory shaker for 2-3 minutes to assure homogeneity. The so obtained mixture was then placed in a K-TronT-35 gravimetric feeder and fed into the Coperion ZSK-26 twin screw extruder, melted, and mixed with screws designed to achieve a homogeneous melt composition. The melt stream was cooled and fed into a Maag Primo 60E pelletizer. The pellets were collected and kept in sealed plastic buckets until used for injection molding.

TABLE-US-00002 TABLE 2 Ryton ® Ryton ® Ep-PDMS Ep-PDMS QA200N QA321N 1200 5000 Mw [wt. %] [wt. %] [wt. %] [wt. %] [g/mol] E7 98.4 — 1.6 — 58,000 CE8 — 98.4 1.6 — n/a CE9 93.6 — — 6.4 57,600 CE10 — 93.6 — 6.4 n/a

[0161] Results

[0162] Table 3 shows the DSC values obtained for the poly(phenylene sulfides) copolymers according to the invention (E1-E3 and E7) in comparison to those of Ryton® QA200N.

TABLE-US-00003 TABLE 3 T.sub.m (° C.) ΔH (J .Math. g.sup.−1) Ryton ® QA200N (Type V bar) 285 42.0 E1 (Type V bar) 285 40.8 E2 (Type V bar) 284 37.6 E3 (Type V bar) 281 37.1 Ryton ® QA200N (ISO bar) 282 44.5 E7 (ISO bar) 283 42.7

[0163] The data reported in Table 3 show that the melting point (T.sub.m) as well as the heat of fusion (ΔH) and, therefore, the degree of crystallinity, of the PDSM-modified poly(phenylene sulfides) according to the invention are substantially unaltered with respect to the unmodified poly(phenylene sulfides), namely Ryton® QA200N.

[0164] Table 4 reports the mechanical properties of the poly(phenylene sulfide) copolymers according Examples 1 to 3 (E1 to E3) in comparison to those of Ryton® QA200N and those of the poly(phenylene sulfide) copolymers according to Comparative Examples 4 to 6 (CE4 to CE6).

TABLE-US-00004 TABLE 4 Tensile stress at Tensile Modulus of break (MPa) elongation (%) elasticity (GPa) Ryton ® QA200N 92.4 4.9 3.77 (Type V bar) E1 (Type V bar) 84.8 7.7 3.83 E2 (Type V bar) 81.4 7.2 3.81 E3 (Type V bar) 75.2 8.9 3.61 CE4 — — — CE5 (Type V bar) 57.6 1.5 4.49 CE6 (Type V bar) 44.5 1.2 4.21

[0165] The data reported in Table 4 show that the bars according to E1 to E3 have a significantly higher tensile elongation than Ryton® QA200N, which means that the PDMS-modified poly(phenylene sulfides) of E1 to E3 have a higher elongation at break and a higher impact resistance than the unmodified poly(phenylene sulfide). Therefore, the PDMS-modified poly(phenylene sulfides) of the present invention are more ductile and tougher than Ryton® QA200N.

[0166] The improvement in ductility and toughness goes without significantly altering the tensile stress at break. Interestingly the modulus of elasticity of the bars according to E1 and E2 is slightly improved.

[0167] The data reported in Table 4 also demonstrate that the copolymers according the invention (E1 to E3) show a significantly improved set of mechanical properties than the copolymers according to the comparative examples (CE4 to CE6). In particular, the bars according to E1 to E3 have a much higher tensile elongation and a higher tensile stress at break than the bars according to CE5 and CE6, while exhibiting only a slightly lower modulus of elasticity. Tensile tests could not be performed on the copolymer of the comparative example CE4 because, due to its poor moldability, it could not be injection molded into tensile bars.

[0168] Table 5 reports the mechanical properties of the poly(phenylene sulfide) copolymer according Example 7 (E7) in comparison to those of Ryton® QA200N and those of the poly(phenylene sulfide) copolymers according to Comparative Examples 8 to 10 (CE8 to CE10).

TABLE-US-00005 TABLE 5 Tensile stress at Tensile Modulus of break (MPa) elongation (%) elasticity (GPa) Ryton ® QA200N 85.3 5.1 3.69 (ISO bar) E7 (ISO bar) 72.1 17 3.56 CE8 — — — CE9 (ISO bar) 65.5 6.1 3.27 CE10 — — —

[0169] The data reported in Table 5 demonstrate that the bar according to E7 shows a significant increase in the elongation at break (higher than 300%) compared to Ryton® QA200N, while showing a very slight decrease in the modulus of elasticity and the tensile stress at break.

[0170] Furthermore, it is evident from the data of Table 5 that the bar according to E7 shows a notably higher elongation break and higher tensile stress at break and modulus of elasticity than the bar according to CE9.

[0171] Tensile tests could not be performed on the copolymers of the comparative examples CE8 and CE10 because they could not be injection molded into tensile bars, due to their poor moldability.

[0172] Therefore, as evident from Tables 4 and 5, the bars according to E1-E3 and E7 show a significantly improved balance between tensile stress at break, modulus of elasticity and tensile elongation, namely an improved balance between ductility, toughness and tensile strength. Said properties make the copolymer according to the invention suitable for different applications including injection molded articles, extrusion molded articles, 3D printed articles and thermoplastic composites.

[0173] Table 6 reports the fracture toughness results of the poly(phenylene sulfide) copolymer according Example 7 (E7) in comparison to those of Ryton® QA200N.

TABLE-US-00006 TABLE 6 Displacement Toughness F max (N) max (mm) (MPa .Math. m.sup.1/2) Ryton ® QA200N 154 0.8 3.88 (ISO bar) E7 (ISO bar) 170 >3 No break

[0174] The data reported in Table 6 demonstrate that the bar according to E7 shows an increase of the maximal force and a huge improvement of the maximum displacement before break with respect to Ryton® QA200N. Furthermore, no break of the bar according to E7 was observed. Fracture toughness of the bar according to E7 was so high that it could not be measured with this methodology. Accordingly, only fracture toughness of Ryton® QA200N was measured.