NOVEL ANTIFOAMING AGENTS

Abstract

The invention relates to the use of a polymer P as antifoaming agent, the polymer P being a linear polymer prepared by polymerization of monomer chosen from monomer M1, monomer M2, or monomer M1 and monomer M2 monomer M1 having the following formula (I): wherein R.sup.1 and R.sup.2, independently of each other, is chosen from: —a benzyl, —a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, and —a (C.sub.3-C.sub.12)cycloalkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, monomer M2 having the following formula (II): wherein R4 represents: a (C.sub.1-C.sub.12)alkyl group or a —CH.sub.2—O—R.sup.5 group, wherein R.sup.5 is chosen from: a benzyl, a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O(C.sub.1-C.sub.12)alkyl, and a (C.sub.3-C.sub.12)cycloalkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, R.sup.3 represents a (C.sub.1-C.sub.12)alkyl group, or R.sup.3 and R.sup.4 form together, with the carbon atom bearing them, a ((C.sub.3-C.sub.12)cycloalkyl group.

##STR00001##

Claims

1. A method for defoaming and/or preventing foam formation in a medium wherein a polymer P as antifoaming agent is added to the medium, the polymer P being a linear polymer prepared by polymerization of monomer chosen from monomer M1, monomer M2, or monomer M1 and monomer M2 monomer M1 having the following formula (I): ##STR00057## wherein R.sup.1 and R.sup.2, independently of each other, is chosen from a benzyl, a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, and a (C.sub.3-C.sub.12)cycloalkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, monomer M2 having the following formula (II): ##STR00058## wherein R.sup.4 represents a (C.sub.1-C.sub.12)alkyl group or a —CH.sub.2—O—R.sup.5 group, wherein R.sup.5 is chosen from a benzyl, a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O(C.sub.1-C.sub.12)alkyl, and a (C.sub.3-C.sub.12)cycloalkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, R.sup.3 represents a (C.sub.1-C.sub.12)alkyl group, or R.sup.3 and R.sup.4 form together, with the carbon atom bearing them, a (C.sub.3-C.sub.12)cycloalkyl group.

2. The method according to claim 1, wherein R.sup.1 and R.sup.2, independently of each other, represent a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group.

3. The method according to claim 1, wherein monomer M2 is a monomer of formula M2′ as follows: ##STR00059## wherein R.sup.5 is chosen from a benzyl, a (C.sub.1-C.sub.12)alkyl group optionally substituted by a —O(C.sub.1-C.sub.12)alkyl, and a (C.sub.3-C.sub.12)cycloalkyl group optionally substituted by a —O—(C.sub.1-C.sub.12)alkyl group, R.sup.3 is as described in claim 1.

4. The method according to claim 1, wherein R.sup.4 represents a group —CH.sub.2—O—R.sup.5 and R.sup.1, R.sup.2, R.sup.3 and R.sup.5 represent, independently of each other, a (C.sub.1-C.sub.4)alkyl group.

5. The method according to claim 1, wherein polymer P is chosen from a statistic copolymer, a diblock copolymer with a structure B1-B2, a diblock copolymer with a structure B2-B1, a triblock copolymer with a structure B1-B2-B1 and a triblock copolymer with a structure B2-B1-B2, block B1 being prepared by polymerization of monomer M1 and block B2 being prepared by polymerization of monomer M2.

6. The method according to claim 1, wherein the polymer P has a number average molar mass Mn comprised from 400 g/mol to 30 000 g/mol.

7. The method according to claim 1, wherein the polymer P has a degree of polymerization DP comprised from 2 to 220.

8. The method according to claim 1, wherein the polymer P has a polydispersity index PDI comprised from 1 to 3.

9. The method according to claim 1, wherein the polymer P has a general formula (III)
R.sup.x—O-[CU]-R.sup.y  (III) wherein notation [CU] represents the constitutive units obtained by polymerization of monomer chosen from monomer M1, monomer M2, or monomer M1 and monomer M2, [CU] can further comprise at least one (C.sub.1-C.sub.12)alkylene group, —R.sup.DG—, linking two constitutive units, R.sup.x is chosen from a hydrogen atom, a —CO—(C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group —R.sup.z, wherein R.sup.z is chosen from a hydroxyl group (OH), a —O—(C.sub.1-C.sub.12)alkyl group, an aliphatic 5- or 6-membered heterocycle, and an aliphatic 5- or 6-membered carbocycle a phenyl, a benzyl, a (C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group —R.sup.z, wherein R.sup.z is as defined above. R.sup.y is chosen from: a hydrogen atom, a —CO—(C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group R.sup.v and a (C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group R.sup.v, wherein R.sup.v is chosen from a hydroxyl group (OH), a —O—(C.sub.1-C.sub.12)alkyl group, a phenyl, a benzyl, an aliphatic 5- or 6-membered heterocycle and an aliphatic 5- or 6-membered carbocycle, a halogen atom chosen from Cl, Br and F, —SO.sub.3H —NH.sub.2 or —NH—(C.sub.1-C.sub.6)alkyl group.

10. The method according to claim 9, wherein R.sup.x and R.sup.y are each a hydrogen atom.

11. The method according to claim 9, wherein R.sup.x is chosen from a —CO—(C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group —R.sup.z, wherein R.sup.z is as defined in claim 9, and a (C.sub.1-C.sub.20)alkyl group optionally substituted by at least one group —R.sup.z, wherein R.sup.z is as defined in claim 9.

12. An antifoam composition, under the form of an emulsion, comprising a polymer P as described in claim 1.

13. The antifoam composition according to claim 12, comprising in wt. % compared to the total weight of the antifoam composition: from 0.01 to 100 of the polymer P, from 0 to 99.99 of a substance chosen among stabilator, emulsifier, antioxidant agent, preservative, thickener, and mixture thereof, the remaining, if any, being water.

14. A polymer prepared by copolymerization of monomer M1 and monomer M2, M1 and M2 being as defined in claim 1 wherein the number average molar mass Mn of polymer P′ is comprised from 400 g/mol to 30 000 g/mol and polymer P′ is not prepared by copolymerization of monomer M1, monomer M2 and THF.

15. The polymer P′ according to claim 14 manufactured according to a process comprising the steps of: (a1) mixing a catalyst and an initiator chosen from an initiator of formula R.sup.xOH, wherein R.sup.x is as defined in claim 9, or an oxetane, (b1+c1) adding to the mixture obtained after step (a1) a monomer chosen from monomer M1, monomer M2 and combinations thereof, (d) then, adding a terminating agent.

16. The method according to claim 8, wherein the polymer P has a polydispersity index PDI comprised from 1.0 to 1.5.

Description

EXAMPLES

[0403] DMO: monomer M2 of formula (II) wherein R.sup.3=R.sup.4=—CH.sub.3 [0404] BMMO: monomer M1 of formula (I) wherein R.sup.1=R.sup.2=—CH.sub.3 [0405] EMMO: monomer M2 of formula (IIa) wherein R.sup.3=—C.sub.2H.sub.5 and R.sup.5=—CH.sub.3 [0406] EBMO: monomer M2 of formula (IIa) wherein R.sup.3=—C.sub.2H.sub.5 and R.sup.5=—C.sub.4H.sub.9 [0407] EOMO: monomer M2 of formula (IIa) wherein R.sup.3=—C.sub.2H.sub.5 and R.sup.5=—C.sub.8H.sub.1 [0408] Th=theoretical [0409] Exp=experimental [0410] DPn=degree of polymerisation [0411] PDi=index of polydispersity

Preparation of Monomers:

[0412] In a 0.5 L flask equipped with a water cooler, polyol (1 equivalent), diethyl carbonate (1.1 equivalent) and KOH (1.5 mol %) were heated at 140° C. After distillation of diethyl carbonate, the media was heated during 2 h at 190° C. Oxetane was purified under vacuum distillation.

Alkylation of Hydroxy Function of Oxetanes:

[0413] NaOH (1.5 eq./OH) was dissolved in water (2 mL/g), then cold down in an ice bath. Oxetane (1 eq.) was introduced in a 0.5 L 2 neck flask and NaOH solution was added dropwise with a dropping funnel. After 1 h in an ice bath under agitation, alkyl iodide (1.5 eq) is added dropwise. Reaction is heated at 100° C. during 5 h. After cooling down, organic phase is extracted with EtOAc. Aqueous phase is neutralized with sulfuric acid and extracted 3 times with EtOAc. Organic phases are combined and wash with NaCl saturated solution, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure. Oxetane is purified by distillation under vacuum.

Example 1—Preparation of Homopolymers without Initiator

[0414] In a 25 mL Schlenk tube purged with Argon, 1 equivalent of monomer oxetane was introduced with dichloromethane (2 mL) and 0.2 equivalent of catalyst (BF.sub.3Et.sub.2O) was added. The reaction is conducted at ambient temperature (about 21° C.). After 10 minutes, reaction was stopped by adding water. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure.

[0415] Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00001 TABLE 1 Monomer Conversion Yield Mn* PDi DMO 99% >90% 19 000 1.01 BMMO 99% >90% 21 500 1.05 EMMO 99% >90% 18 700 1.04 EOMO (6) 99% >90% 22 600 1.01 *determined by SEC

[0416] Very good yields as well as very low PDI are obtained. A short reaction time coupled with a very low PDI is coherent with the mechanism of a living CROP. An average Mn of 20,000 g/mol is obtained for the homopolymerization of the disubstituted 3,3 oxetanes.

Example 2—Preparation of Diblocs without Initiator

[0417] In a 25 mL Schlenk tube purged with Argon, n equivalent of EMMO (first monomer oxetane) was introduced with dichloromethane (2 mL) and 20 mol % of catalyst (BF.sub.3Et.sub.2O) was added. The reaction is conducted at ambient temperature (about 21° C.). After 10 minutes, m equivalent of BMMO (second monomer oxetane) was introduced. The reaction is conducted at ambient temperature (about 21° C.). After 10 minutes, reaction was stopped by adding water. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure.

[0418] Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00002 TABLE 2 Ratio Mn.sub.sec n.sub.equivalentEMMO n.sub.equivalentsBMMO Conversion RMN* PDi (g/mol) Yield 1 0 99% 1:0 1.01 18 000 90% 2 1 96% 2:1 1.01 26 600 85% 4 1 98% 4:1 1.04 18 400 75% 8 1 99% 7.5:1.sup.  1.04 19 250 95% 16 1 98% 23:1  1.01 25 600 95% *the ratio of each block is determined by NMR.

[0419] With a methoxy function and an ethyl chain, the EMMO monomer is more hydrophobic than the BMMO monomer (which carries 2 methoxy functions but does not carry an ethyl chain). Adding BMMO repeating units to the copolymer provides hydrophilicity. The addition of ⅓ of hydrophilic monomer, ie a final ratio of 2:1 between the hydrophobic monomer and the hydrophilic monomer makes it possible to obtain a copolymer of 26,600 g/mol with 85% yield. The ratio between each monomer is confirmed by NMR. Similarly, the reduction of the hydrophilic part by 20%, then 10% and finally 5% makes it possible to obtain copolymers with excellent yields (75%-95%) and molecular weights of 18,400 to 25,600 g/mol. In accordance with the observations made during the homopolymerization (Example 1), the polydispersity of the copolymers obtained is very low. Living copolymerization provides access to amphiphilic polyethers with very good yields and Mn between 18,000 g/mol and 25,600 g/mol.

Example 3—Homopolymerisation of EMMO Under Different Polymerisation Conditions without Initiator

[0420] In a 25 mL Schlenk tube purged with Argon, 1 equivalent of EMMO (monomer oxetane) was introduced with dichloromethane (X mL) and Y equivalent of catalyst was added. After Z minutes, reaction was stopped by adding water. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure.

With Different Catalysts

[0421] The general procedure disclosed above was followed. 1 equivalent of EMMO was introduced with dichloromethane (2 mL). 20 mol % of catalyst is added; the nature of the catalyst varied. The reaction is conducted at ambient temperature (about 21° C.). The reaction is stopped after 10 min. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00003 TABLE 3 Catalyst Conversion Yield Mn (g/mol) PDi H.sub.2SO.sub.4 99% >90% 29 500 1.05 BF.sub.3Et.sub.2O 99% >90% 18 700 1.04 BF.sub.3AcOH 99% >90% 19 000 1.04 AlCl.sub.3 99% >90% 40 100 1.02

Catalyst Concentration

[0422] The general procedure disclosed above was followed. 1 equivalent of EMMO was introduced with dichloromethane (2 mL) The concentration of catalyst (BF.sub.3Et.sub.2O) varied. The reaction is conducted at ambient temperature (about 21° C.). The duration of reaction was also increased when the catalyst concentration was low. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00004 TABLE 4 Catalyst amount Reaction Mn (X mol %) duration Conversion.sup.b Yield (g/mol) PDi 5 10 min 99 >90% 18 400 1.01 10 10 min 99 >90% 19 200 1.01 20 10 min 99 >90% 18 700 1.04 0.1 14 hours 99 >90% 28 700 1.01 1 14 hours 99 >90% 23 100 1.01 .sup.bCalculated by NMR

Monomer Concentration

[0423] The general procedure disclosed above was followed. 20 mol % of catalyst (BF.sub.3Et.sub.2O) is added. The solvent content varied so that the monomer concentration varied. The reaction is conducted at ambient temperature (about 21° C.). The reaction is stopped after 10 min. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00005 TABLE 5 Monomer concentration [C] (mol/L) 1.8 mol/L 1 mol/L 0.1 mol/L* 0.05 mol/L* Mn (g/mol) 29000 27800 33100 33100 *After total conversion of the monomer (reaction time = 16 h) No correlation between monomer concentration and Mn of the polymer is noted.

Reaction Time

[0424] The general procedure disclosed above was followed. 1 equivalent of EMMO was introduced with dichloromethane (2 mL). 20 mol % of catalyst (H.sub.2SO.sub.4) is added. The reaction is conducted at ambient temperature (about 21° C.). Reaction lasted from 1 min to 1 day. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00006 TABLE 6 Reaction Mn duration Conversion Yield (g/mol) PDi 2 min 90 — — — 10 min 99 >90 29 100 1.01 1 h 99 >90 29 900 1.01 3 h 99 >90 29 900 1.01 24 h 99 >90 31 800 1.01

Temperature

[0425] The general procedure disclosed above was followed. 1 equivalent of EMMO was introduced with dichloromethane (2 mL). 20 mol % of catalyst (BF.sub.3Et.sub.2O) is added. The temperature varied. The duration of reaction was also increased when the temperature was negative. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00007 TABLE 7 Temperature Reaction (° C.) duration Conversion Yield Mn (g/mol) PDi 20 10 min 99 >90 18 700 1.04 50 10 min 99 >90 17 700 1.04 80 10 min 99 >90 19 100 1.01 −10 17 hours 97 >90 24 200 1.01

[0426] When the temperature decreases, the reaction is slower, but without significant impact on Mn of the polymer.

Example 4—Polymerisation with Initiator

[0427] In a 25 mL Schlenk tube purged with Argon, X mmol of initiator and X mmol of catalyst (1 eq./OH function) were introduced with 2 mL of solvent (dichloromethane). After 1 hour, Y mmol of monomer oxetane solubilized in solvent (dichloromethane) was added. After Z min, reaction was stopped by adding termination agent. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure.

[0428] Theorical polymerization degree is

[00001]$n=\frac{Y}{X}.$

[0429] Molecular weight is calculated following the equation: Mn.sub.experimental=M.sub.initiator+DP.sub.experimental×M.sub.monomer+M.sub.terminaison.

[0430] Experimental polymerization degree is determined by NMR: [0431] Protons corresponding to group CH.sub.3=3H [0432] Protons corresponding to initiator CH.sub.2=2H

[00002]$\mathrm{Number}\mathrm{of}\mathrm{repetition}\mathrm{units}=\{\frac{3*2}{\mathrm{integration}\mathrm{of}CH2\mathrm{of}\mathrm{initiator}})/3$

[0433] Here the monomer oxetane was DMO (n equivalents), the initiator was benzylic alcohol (1 equivalent), the catalyst was BF.sub.3Et.sub.2O (1 equivalent) and the terminating agent was water.

[0434] The reaction is stopped after 10 min.

[0435] Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00008 TABLE 8 Mn exp n equivalent Conversion Yield DPn th DPn exp (g/mol) 9 99% >90% 9 8 820 15 99% >90% 15 15 1400 16 99% >90% 16 17 1600 27 99% >90% 27 26 2400 36 99% >90% 36 36 3200

[0436] Very good conversions and very good yields are obtained. The Mn expected and measured by NMR are in agreement. The end of the chain from the initiator is characteristic on the NMR spectrum thanks to the aromatic group.

[0437] Similarly, the following polymers have been synthetized.

Monomers Screening

[0438] The general procedure disclosed above was followed. Here the nature of the monomer oxetane (15 equivalent) varied, the initiator was butan-1-ol (1 equivalent), the catalyst was BF3Et2O (1 equivalent) and the terminating agent was water. The reaction is stopped after 10 min. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00009 TABLE 9 Monomer Conversion Yield Mn th Mn exp DMO 99% >90% 1400 1400 BMMO 99% >90% 2200 2000 EMMO 99% >90% 2100 1800 EOMO 99% >90% 2900 2700

[0439] The results obtained show total conversions to monomers (90-99%) and high yields (>90%) The chain ends from the butanol initiator are identified by NMR and allow the DPn to be estimated with precision. The final Mn are in agreement with the expected Mn.

Degree of Polymerisation

[0440] The general procedure disclosed above was followed. Here monomer oxetane was EMMO (n equivalent), the initiator was butan-1-ol (1 equivalent, 1 mmol), the catalyst was BF.sub.3Et.sub.2O (1 equivalent, 1 mmol) and the terminating agent was water. The reaction is stopped after 10 min. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00010 TABLE 10 n Mn.sub.exp equivalent Conversion Yield DPn.sub.th DPn.sub.exp (g/mol) 3 99% >90% 3 3 476 4 96%  87% 4 4 610 15 99% >90% 15 13 1800 25 99% >90% 25 25 3400 50 97%  89% 50 52 7000

[0441] NMR spectra make it possible to determine the chain size of the polymer using the chain end of the butanol initiator. For chain sizes>30 units, a 500 MHz spectrometer is used to properly view the end of the polymer chain from the initiator

[0442] In addition to having obtained a total conversion of the monomers (>95%) and very good yields (>85%), the PD calculated by NMR are in agreement with the expected PD. It is possible to selectively prepare the dimer, trimer or tetramer.

[0443] Screening of Initiator

[0444] The general procedure disclosed above was followed. Here monomer oxetane was EMMO (12 equivalents), the initiator varied (1 equivalent, 1 mmol), the catalyst was BF.sub.3Et.sub.2O (1 equivalent, 1 mmol) and the terminating agent was water. The reaction is stopped after 3 hours. Following this procedure, the polymers disclosed in the table below have been prepared.

TABLE-US-00011 TABLE 11 n Con- Mn.sub.exp Initiator .sub.equivalent version yield DP.sub.th DP.sub.exp .sub.(g/mol) MeOH 15 99% >90% 15 17 2200 [00020] 15 99% >90% 15 13 1800 [00021] 15 99% >90% 15 16 2200 [00022] 15 97%   89% 15 16 2200 [00023] 15 97% >90% 15 16 2200 [00024] 15 99% >90% 15 13 1800 [00025] 13 98% >90% 13 11 1600 [00026] 12 99% >90% 12 12 1700 [00027] 4 98% >90% 4 4 628

[0445] Initiating with different sizes of carbon chains makes it possible to provide hydrophobic properties without influencing the final yield of the polymer or the final Mn. The DPn is checked and the yields obtained are very good.

Example 5—Copolymerisation with Initiator

[0446] In a 25 mL Schlenk tube purged under Argon, X mmol of initiator and X mmol of catalyst (1 eq./OH function) were introduced with 2 mL of solvent (dichloromethane). After 1 hour, Y mmol (n1 equivalent) of the first monomer oxetane solubilized in solvent (dichloromethane) were added. After 2 hours, Z mmol (n2 equivalent) of the second monomer oxetane were introduced. After 2 hours, reaction was stopped by adding termination agent. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4 filtrated, and concentrated under reduce pressure. Theorical DP of bloc monomer 1: Y/X and theorical DP of block monomer 2: Z/X. Mn.sub.total=M.sub.initiator+DP.sub.1×M.sub.monomer 1+DP.sub.2×M.sub.monomer 2.

[0447] Here, 1 mmol of butan-1-ol was added to 1 mmol BF.sub.3Et.sub.2O, the termination agent is water.

TABLE-US-00012 TABLE 12 n.sub.equivalent 1 n.sub.equivalents 2 Conversion DPn.sub.th DPn.sub.expl Mn.sub.exp (g/mol) Yield 13 0 99% 13 13 2000 97% 12 1 96% 12:1  11:1  2000 80% 10 2 98% 10:2  9:2 1700 82% 8 5 99% 8:5 8:5 1900 97% 6 6 98% 6:6 5:6 1600 92% 4 8 98% 4:8 4:8 1700 92% 0 13 99%  0:13 13 1800 >90% 

[0448] The copolymer obtained is diblock. The variation in the percentage between each block of the copolymer has no impact on the conversion, the yield or the final DPn.

[0449] Increasing the percentage of the hydrophobic block does not affect the final yield. The copolymers obtained have DPn between 11 and 13 units (or Mn from 1700 to 2000 g/mol).

[0450] The percentage of each monomer can be calculated by NMR by integrating the CH.sub.3 of the ethyl group of the EMMO monomer. Similarly, the length of the copolymer chain is calculated by integrating the end of the butanol initiator chain.

Example 6—Sequential Copolymerisation with Initiator

[0451] To 1 mmol of propanediol is added 2 mmol of BF3Et2O. After 1 h at 21° C. under argon, “n” equivalents of the 1st monomer are added. After complete conversion, the chain is terminated by adding methanol. The polymer is purified and isolated. The NMR analysis reveals the end of the chain originating from the propanediol initiator, carrying a hydroxyalkyl function.

[0452] 1 mmol of the homopolymer is added in the presence of 1 mmol of BF.sub.3Et.sub.2O. After 1 h at 21° C. under argon, “n” equivalents of the monomer are added. After complete conversion, the reaction is terminated by adding water. The final polymer is purified and isolated. NMR analysis reveals the disappearance of the hydroxyalkyl group. The chain growth on the end of the 1st homopolymer is effective. The DP of the second chain is calculated by making the integration difference between the total of the polymer and the 1st chain.

Example 7—Polymerisation of EMMO with Sulfuric Acid as Catalyst without Solvent

[0453] In a 25 mL Schlenk tube purged with Argon, 1 molar equivalent of butan-1-ol and 1 molar equivalent of H.sub.2SO.sub.4 were introduced. After 1 hour, 21° C., 7 molar equivalent of monomer oxetane (EMMO) was added. After 3 hours, reaction was stopped by adding water. Organic phase was extracted 3 times with dichloromethane, dried over MgSO.sub.4, filtrated, and concentrated under reduce pressure.

[0454] The homopolymer is obtained with a yield of 92%. The conversion is 93%. The polymer has a DPn of 7 and Mn of 1024 g/mol.

Example 8—Antifoaming Tests

[0455] The general procedure disclosed in the examples above was followed and homopolymers, diblocks have been prepared.

[0456] 50 ml of a 0.1 g/L Sodium lauryl ether sulfate (SLES) solution is introduced into a glass container. After magnetic stirring for 2 minutes, we note the appearance of 150 mL of foam. After adding 0.2% by mass of active material (antifoaming agent) and stirring, the volume of remaining foam is measured. The results are presented in the following table. The antifoam effect corresponds to the reduction of foam volume (in % by volume).

TABLE-US-00013 TABLE 13 Mn Antifoam Antifoaming agent formula (g/mol) method effect [00028] 18000 Homopolymerization without initiator −70% [00029] 21500 Homopolymerization without initiator −70% [00030] 17500 Homopolymerization without initiator −60% [00031] 19000 Homopolymerization without initiator −80% [00032] 25600 Copolymerization without initiator −60% [00033] 19250 Copolymerization without initiator −60% [00034] 18400 Copolymerization without initiator −50% [00035] 26600 Copolymerization without initiator −60% [00036] 476 Homopolymerization with initiator −50% [00037] 610 Homopolymerization with initiator −60% [00038] 1800 Homopolymerization with initiator −60% [00039] 3400 Homopolymerization with initiator −60% [00040] 7000 Homopolymerization with initiator −50% [00041] 2200 Homopolymerization with initiator −40% [00042] 2200 Homopolymerization with initiator −70% [00043] 2200 Homopolymerization with initiator −70% [00044] 2200 Homopolymerization with initiator −50% [00045] 1800 Homopolymerization with initiator −60% [00046] 1600 Homopolymerization with initiator −80% [00047] 628 Homopolymerization with initiator −60% [00048] 1700 Homopolymerization with initiator −60% [00049] 810 Homopolymerization with initiator −50% [00050] 1700 Copolymerization with initiator −80% [00051] 1600 Copolymerization with initiator −70% [00052] 1900 Copolymerization with initiator −80% [00053] 1700 Copolymerization with initiator −60% [00054] 2000 Copolymerization with initiator −80% [00055] 2000 Copolymerization with initiator −85% [00056]

[0457] Homopolymers have an anti-foaming character of −70% on average.

[0458] The amphiphilic copolymers all have an anti-foaming character of approximately −60%.