POLY(ARYLENE SULFIDE) AND PROCESS FOR ITS MANUFACTURING

Abstract

The present invention relates to a poly(arylene sulfide) (PAS), comprising recurring units p, q and r according of formula (I) wherein n.sub.p, n.sub.q and n.sub.r are respectively the mole % of each recurring units p, q and r; recurring units p, q and r are arranged in blocks, in alternation or randomly; 2≤(n.sub.q+n.sub.r)/(n.sub.p+n.sub.q+n.sub.r)≤9; n.sub.q is ≥0% and n.sub.r is ≥0%; j is zero or an integer varying between 1 and 4; R.sup.1 is selected from the group consisting of halogen atoms, C.sub.1-C.sub.12 alkyl groups, C.sub.7-C.sub.24 alkylaryl groups, C.sub.7-C.sub.24 aralkyl groups, C.sub.6-C.sub.24 arylene groups, C.sub.1-C.sub.12 alkoxy groups, and C.sub.6-C.sub.18 aryloxy groups.

##STR00001##

Claims

1-15. (canceled)

16. A poly(arylene sulfide) (PAS), comprising recurring units p, q and r according of formula (I): ##STR00007## n.sub.p, n.sub.q and n.sub.r are respectively the mole % of each recurring units p, q and r; recurring units p, q and r are arranged in blocks, in alternation or randomly; 2%≤(n.sub.q+n.sub.r)/(n.sub.p+n.sub.q+n.sub.r)≤9%; n.sub.q is ≤0% and n.sub.r is ≤0%; j is zero or an integer varying between 1 and 4; R.sup.1 is selected from the group consisting of halogen atoms, C.sub.1-C.sub.12 alkyl groups, C.sub.7-C.sub.24 alkylaryl groups, C.sub.7-C.sub.24 aralkyl groups, C.sub.6-C.sub.24 arylene groups, C.sub.1-C.sub.12 alkoxy groups, and C.sub.6-C.sub.18 aryloxy groups, wherein the PAS has a heat of fusion of more than 20 J/g, 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.

17. The PAS according to claim 16, wherein n.sub.p+n.sub.q+n.sub.r≤50%.

18. The PAS according to claim 16, consisting essentially of recurring units p, and recurring units q and/or r.

19. The PAS according to claim 16, wherein j is zero in formula (I).

20. The PAS according to claim 16, having a melt flow rate MFR (at 315.6° C. under a weight of 1.27 kg according to ASTM D1238, procedure B) of at most 700 g/10 min and/or of at least 1 g/10 min.

21. The PAS according to claim 16, having a melting point of at most 280° C. and/or of at least 252° 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.

22. A process for manufacturing the poly(arylene sulfide) (PAS) of formula (I) according to claim 16, comprising a step of oxidizing solid particles of a poly(arylene sulfide) (PAS-p) comprising recurring units p according to formula (VII): ##STR00008## j is zero or an integer varying between 1 and 4; R.sup.1 is selected from the group consisting of halogen atoms, C.sub.1-C.sub.12 alkyl groups, C.sub.7-C.sub.24 alkylaryl groups, C.sub.7-C.sub.24 aralkyl groups, C.sub.6-C.sub.24 arylene groups, C.sub.1-C.sub.12 alkoxy groups, and C.sub.6-C.sub.18 aryloxy groups, wherein said step of oxidation takes place in a liquid containing an oxidizing agent.

23. The process according to claim 22, wherein said liquid contains acetic acid.

24. The process according to claim 22, wherein said oxidizing agent is hydrogen peroxide.

25. The process according to claim 22, wherein the step of oxidizing the PAS-p is carried out at a temperature lower than 100° C. and/or higher than 10° C.

26. A polymer composition (C), comprising: the poly(arylene sulfide) (PAS) of formula (I) according to claim 16, up to 65 wt. %, based on the total weight of the polymer composition, of at least one additional component selected from the group consisting of fillers, reinforcing agents, elastomers, colorants, dyes, pigments, lubricants, plasticizers, flame retardants, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electomagnetic absorbers and combinations thereof.

27. The polymer composition (C) according to claim 26, comprising from 10 to 60 wt. % of glass fibers and/or carbon fibers.

28. A method for manufacturing the composition (C) according to claim 26, comprising mixing said poly(arylene sulfide) (PAS) of formula (I) and said at least one additional component.

29. An article, part or composite material comprising the poly(arylene sulfide) (PAS) of formula (I) according to claim 16.

30. A method for using the article, part or composite material of claim 29, the method comprising using the article part or composite material in oil and gas applications, automotive applications, electric and electronic applications, aerospace and consumer goods.

Description

EXPERIMENTAL SECTION

[0110] Materials

[0111] Ryton® QA281N is a poly(phenylene sulfide) commercially available from Solvay Specialty Polymers USA.

[0112] Hydrogen peroxide 30% w/w aqueous solution was purchased from Fischer.

[0113] Acetic acid with purity of 99% was purchased from VWR.

[0114] Methods

[0115] DSC/Heat of Fusion

[0116] DSC analyses were carried out on DSC Q200-5293 TA Instrument 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.

[0117] GPC

[0118] Mn and Mw were determined by gel permeation chromatography (GPC) at 210° C. using a PL 220 high temperature GPC with a 1-chloronaphtalene mobile phase.

[0119] Melt Flow Index

[0120] The melt flow index was determined according to ASTM D1238 at 315.6° C. with a 1.27 kg weight.

[0121] Mechanical Testing

[0122] Test specimens were injection molded into Type V tensile bars according to ASTM D3641, using a barrel temperature set at Tm+30° C. in a mold regulated at 130° C. Mechanical tests were performed on injection molded test specimens with a gauge length of 0.3 inch using the Instron 5569 machine and according to ASTM D638 at 23.2° C. with 54.7% humidity.

SYNTHESIS EXAMPLES

Example 1 (Ex. 1)

[0123] Ryton® QA281N (200 g, 1.0 eq) was suspended in acetic acid (400 mL) under a nitrogen atmosphere inside a 1 L reactor equipped with an inclined quadripale type stirrer, a condenser, a double jacket for heating and a syringe pump.

[0124] The resulting suspension was stirred at room temperature and hydrogen peroxide 30% w/w (6.0 g, 0.03 eq) was added via syringe pump over a period of 15 minutes.

[0125] The temperature was raised to 70° C. (double jacket set at 75° C.) and the reaction mixture was stirred for 3 hours at this temperature. The stirring speed was set to 300 rpm. Then, an analysis of the supernatant with Quantofix peroxide test sticks confirmed the absence of peroxide.

[0126] The reaction mixture was then cooled to room temperature and filtered. The recovered solids were washed twice with acetic acid at room temperature (2×100 mL). The solids were then dried in a rotating evaporator under a pressure of 20 mbar and at a temperature of 50° C. for 2 hours. The recovered solids were than dried under vacuum (˜20 mbar) at 120° C. for 7 hours.

[0127] The obtained product is a poly(phenylene sulfide) of formula (I), wherein j=0, n.sub.p=97%, n.sub.q+n.sub.r=3%. Accordingly, under these conditions 3 mol. % of the sulfide moieties of Ryton® QA281N have been oxidized into sulfoxide and sulfone moieties.

Example 2 (Ex. 2)

[0128] Ryton® QA281N (200 g, 1.0 eq) was suspended in acetic acid (400 mL) under a nitrogen atmosphere inside a 1 L reactor equipped with an inclined quadripale type stirrer, a condenser, a double jacket for heating and a syringe pump.

[0129] The resulting suspension was stirred at room temperature and hydrogen peroxide 30% w/w (10.0 g, 0.05 eq) was added via syringe pump over a period of 15 minutes.

[0130] The temperature was raised to 70° C. (double jacket set at 75° C.) and the reaction mixture was stirred for 3 hours at this temperature. The stirring speed was set to 300 rpm. Then, an analysis of the supernatant with Quantofix peroxide test sticks confirmed the absence of peroxide.

[0131] The reaction mixture was then cooled to room temperature and filtered. The recovered solids were washed twice with acetic acid at room temperature (2×100 mL). The solids were then dried in a rotating evaporator under a pressure of 20 mbar and at a temperature of 50° C. for 2 hours. The recovered solids were than dried under vacuum (˜20 mbar) at 120° C. for 7 hours.

[0132] The so obtained product is a poly(phenylene sulfide) of formula (I), wherein j=0, n.sub.p=95%, n.sub.q+n.sub.r=5%. Accordingly, under these conditions 5 mol. % of the sulfide moieties of Ryton® QA281N have been oxidized into sulfoxide and sulfone moieties.

Comparative Example (Ex. 3C)

[0133] Ryton® QA281N (200 g, 1.0 eq) was suspended in acetic acid (400 mL) under a nitrogen atmosphere inside a 1 L reactor equipped with an inclined quadripale type stirrer, a condenser, a double jacket for heating and a syringe pump.

[0134] The resulting suspension was stirred at room temperature and hydrogen peroxide 30% w/w (20.0 g, 0.1 eq) was added via syringe pump over a period of 15 minutes.

[0135] The temperature was raised to 70° C. (double jacket set at 75° C.) and the reaction mixture was stirred for 3 hours at this temperature. The stirring speed was set to 300 rpm. Then, an analysis of the supernatant with Quantofix peroxide test sticks confirmed the absence of peroxide.

[0136] The reaction mixture was then cooled to room temperature and filtered. The recovered solids were washed twice with acetic acid at room temperature (2×100 mL). The solids were then dried in a rotating evaporator under a pressure of 20 mbar and at a temperature of 50° C. for 2 hours. The recovered solids were than dried under vacuum (˜20 mbar) at 120° C. for 7 hours.

[0137] The so obtained product is a poly(phenylene sulfide) of formula 1, wherein j=0, n.sub.p=90%, n.sub.q+n.sub.r=10%. Accordingly, under these conditions 10 mol. % of the sulfide moieties of Ryton® QA281N have been oxidized into sulfoxide and sulfone moieties.

[0138] Results

[0139] Table 1 shows the DSC values obtained for the poly(phenylene sulfides) synthesized according to Ex. 1 and Ex. 2. Said values are compared to those of Ryton® QA281N and the poly(phenylene sulfide) synthesized according to Ex. 3C.

TABLE-US-00001 TABLE 1 Oxidized moieties T.sub.g T.sub.mc T.sub.m ΔH [mol. %] [° C.] [° C.] [° C.] [J .Math. g.sup.−1] Ryton ® 0 92.9 231.6 282.5 93.3 QA281N Ex.1 3 95.7 224.8 275.4 63.8 Ex.2 5 97.9 203.5 268.9 59.9 Ex.3C 10 101.9 — 251.7 15.9

[0140] As evident from Table 1, the glass transition temperature (T.sub.g) value increases with the mol. % increase of the oxidized moieties. In other words, the T.sub.g value increases along with the oxidation state of the poly(phenylene sulfide). On the contrary, the melting temperature (T.sub.m) and the melt crystallization temperature (T.sub.mc) decrease with the mol. % increase of the oxidized moieties. No melt crystallization temperature upon cooling was detected for the poly(phenylene sulfide) according to Ex. 3C.

[0141] As evident from Table 1, the heat of fusion (ΔH) and, therefore, the crystallinity of the poly(phenylene sulfides) synthesized according to Ex. 1, Ex. 2 and Ex. 3C are lower than of Ryton® QA281N.

[0142] Table 2 shows the number average molecular weight (Mn) and the weight average molecular weight (Mw) of Ryton® QA281N and of the poly(phenylene sulfides) synthesized according to Ex. 1, Ex. 2 and Ex. 3C.

TABLE-US-00002 TABLE 2 Oxidized moieties Mn Mw [mol. %] (g/mol) (g/mol) Ryton ® QA281N 0 14280 36200 Ex.1 3 17810 42180 Ex.2 5 18250 42670 Ex.3C 10 16610 40810

[0143] As evident from Table 2, the Mw increases with the mol. % increase of the oxidized moieties compared to Ryton® QA281N, but remains consistent for the poly(phenylene sulfides) of Ex. 1, Ex. 2 and Ex. 3C.

[0144] Table 3 shows the melt flow index of the poly(phenylene sulfides) synthesized according to Ex. 1 and Ex. 2 in comparison with those of Ryton® QA281N and the poly(phenylene sulfide) synthesized according to Ex. 3C.

TABLE-US-00003 TABLE 3 Oxidized moieties Melt flow index [mol. %] (g/10 min) Ryton ® QA281N 0 40 Ex.1 3 17 Ex.2 5 2 Ex.3C 10 N/A

[0145] Interestingly and surprisingly, as evident from Table 3, there is a steady decrease of the melt flow index with the mol. % increase of the oxidized moieties and, accordingly, a steady increase of the viscosity along with the mol. % of the oxidized moieties. As a result, the poly(phenylene sulfides) of Ex. 1 and Ex. 2 can be advantageously used for extrusion molding applications. On the contrary, the viscosity of Ryton® QA281N is not sufficiently high for such applications, and the viscosity of the poly(phenylene sulfide) of Ex. 3 appears to be too high so that the polymer degraded during the experiment.

[0146] Table 4 reports the mechanical properties of the poly(phenylene sulfides) of Ex. 1 and Ex. 2 in comparison with those of Ryton® QA281N and the poly(phenylene sulfide) of Ex. 3C. The poly(phenylene sulfides) of Ex. 1 and Ex. 2 had similar molding ability to the reference polymer Ryton® QA281N. The poly(phenylene sulfide) of Ex. 3C was more challenging to mold.

TABLE-US-00004 TABLE 4 Oxidized Stress at Tensile Modulus of moieties break elongation elasticity [mol. %] [MPa] [%] [GPa] Ryton ® QA281N 0 87 4.4 3.61 Ex.1 (tensile bar) 3 83 5.1 3.32 Ex.2 (tensile bar) 5 70 7.2 3.55 Ex.3C (tensile bar) 10 59 3.2 3.34

[0147] The data reported in Table 4 show that the tensile stress at break and the modulus of elasticity of the bars according to Ex. 1 and Ex. 2 are not significantly decreased when compared to Ryton® QA281N. This means that the poly(phenylene sulfides) according to Ex. 1 and Ex. 2 have tensile strength properties similar to those of Ryton® QA281N. On the contrary, the bar according to Ex. 3C has lower tensile stress at break and, therefore, a lower tensile strength than Ryton® QA281N and the poly(phenylene sulfides) of Ex. 1 and Ex. 2 according to the present invention.

[0148] Table 4 also shows that the bars according to Ex. 1 and Ex. 2 have higher tensile elongation than Ryton® QA281N, which means that the poly(phenylene sulfides) of Ex. 1 and Ex. 2 have a higher elongation at break and a higher impact resistance, namely they are more ductile and tougher than Ryton® QA281N. Surprisingly, the bar according to Ex. 3C has a lower elongation at break than both the Ryton® QA281N and the bars of Ex. 1 and Ex. 2 according to the present invention.

[0149] Therefore, as evident from Table 4, the poly(phenylene sulfides) according to Ex. 1 and Ex. 2, having an oxidation between 2 and 9 mol. %, show an 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 poly(phenylene sulfides) according to the invention suitable for different applications including injection molded articles, extrusion molded articles, 3D printed articles and thermoplastic composites. On the contrary, Ryton® QA281N shows very low tensile elongation and the poly(phenylene sulfide) according to Ex. 3C shows both very low tensile stress at break and very low elongation at break.