Foam material comprising polyphenylene sulfide polymer (PPS)

Abstract

The invention relates to a foam material (FP) comprising a polymer composition (C) comprising at least a polyphenylene sulfide polymer (PPS) and at least one functionalized elastomer (E). The present invention also relates to a process for the manufacture of said foam material and to an article (A) including said foam material (FP), for example a composite material.

Claims

1. A foam material (FP) comprising a polymer composition (C), which comprises: at least one polyphenylene sulfide polymer (PPS), and from 1 to 40 wt. % of at least one functionalized elastomer, the wt. % being based on the total weight of (C).

2. The foam material of claim 1, wherein at least 50 mol. % of the recurring units of the PPS polymer are recurring units (R.sub.PPS) of formula (L) (mol. % being based on the total number of moles in the PPS polymer): ##STR00005## wherein: each R is independently 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, and i is an integer from 0 to 4.

3. The foam material of claim 1, wherein the functionalized elastomer is a non-aromatic elastomer.

4. The foam material of claim 1, wherein the functionalized elastomer is selected from the group consisting of copolymers of ethylene and glycidyl (meth)acrylate; terpolymers of ethylene, acrylic ester and glycidyl (meth)acrylate; copolymers of ethylene and butyl ester acrylate; terpolymers of ethylene, butyl ester acrylate and glycidyl methacrylate; ethylene-maleic anhydride copolymers; ethylene-propylene-rubbers grafted with maleic anhydride (EPR-g-MAH); ethylene-propylene-diene monomer rubbers grafted with maleic anhydride (EPDM-g-MAH) and mixture thereof.

5. The foam material of claim 1, further comprising from 0.01 to 5 wt. % of at least one nucleating agent.

6. The foam material of claim 5, wherein the nucleating agent is selected from the group consisting of glass fibers, talc, calcium carbonate, silica, silicate, boron nitride, titanium dioxide, and carbon black.

7. The foam material of claim 1, wherein the polymer composition further comprises up to 40 wt. % of at least one filler (F).

8. The foam material of claim 1, having a density from 200 to 1,200 kg/m.sup.3, as measured according to ASTM D1622.

9. An article (A) including at least a part comprising the foam material (FP) according to claim 1.

10. The article (A) according to claim 9, wherein the article is selected from the group consisting of an airplane cabin interior component, a medical device, a thermal or acoustic insulation article and a portable electronic device.

11. A process for manufacturing a foam material (FP), said process comprising the steps of: preparing a foamable polymer composition (FC) which comprises: at least one polyphenylene sulfide polymer (PPS), from 1 to 40 wt. % of at least one elastomer, from 0.01 to 10 wt. % of at least one blowing agent, the wt. % being based on the total weight of (C), foaming the foamable polymer composition (FC) using a process selected from the group consisting of a pressure cell process, an autoclave process, an extrusion process, direct injection process, blow molding process and bead foaming.

12. The process of claim 11, wherein the blowing agent comprises a tetrazole compound selected from the group consisting of formulas (T-1), (T-2), (T-3) and (T-4): ##STR00006## wherein R.sub.1 is selected from a group consisting of alkyl, cycloalkyl, arylalkyl and aryl group, R.sub.2 is selected from a group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkylene, alkenyl, alkenylaryl and alkenylaralkylene group, optionally substituted, R.sub.1′ and R.sub.2′, are independently selected from a group consisting of a bond and a divalent group optionally comprising one or more heteroatoms, n is an integer equal to 2 or 3, and M is a metal cation selected from the group consisting of barium, calcium, zinc, lead and aluminium.

13. The process of claim 11, wherein the polymer composition further comprises an olefinic polymer selected from the group consisting of a high-density polyethylene (HDPE), a linear low-density polyethylene (LLDPE), a low-density polyethylene (LDPE), a very-low-density polyethylene (VLDPE), a propylene homopolymer, a propylene copolymer, a linear homogeneous ethylene/alpha-olefin copolymer and a homogeneous ethylene/alpha-olefin copolymer having long chain branching.

14. A foamable polymer composition (FC), comprising: at least one polyphenylene sulfide polymer (PPS), from 1 to 40 wt. % of at least one elastomer, and from 0.01 to 10 wt. % of at least one blowing agent, the wt. % being based on the total weight of (C).

15. The foamable polymer composition (FC) of claim 14, further comprising: from 0.01 to 5 wt. % of at least one nucleating agent selected from the group consisting of glass fibers, talc, calcium carbonate, silica, silicate, boron nitride, titanium dioxide, and carbon black, and/or at least one additive (AD) selected from the group consisting of chemical foaming agent, residues of chemical foaming agent, UV absorber, stabilizer, lubricant, plasticizer, anti-static agents, metal deactivators, and mixtures thereof and/or an olefinic polymer selected from the group consisting of a high-density polyethylene (HDPE), a linear low-density polyethylene (LLDPE), a low-density polyethylene (LDPE), a very-low-density polyethylene (VLDPE), a propylene homopolymer, a propylene copolymer, a linear homogeneous ethylene/alpha-olefin copolymer and a homogeneous ethylene/alpha-olefin copolymer having long chain branching.

Description

EXAMPLES

(1) Raw Materials

(2) PPS Ryton® QA200N commercially available from Solvay Specialty Polymers USA, L.L.C.

(3) Elastomer #1: Lotader® AX8840 commercially available from Arkema, copolymer of ethylene and glycidyl methacrylate (epoxy functionalized)

(4) Elastomer #2: Lotader® AX8900 commercially available from Arkema, terpolymer of ethylene, acrylic ester and glycidyl methacrylate (epoxy functionalized)

(5) Elastomer #3: Elvaloy® AS commercially available from Dupont, terpolymer of ethylene, n-butyl acrylate and glycidyl methacrylate (epoxy functionalized)

(6) Carbon Black (particle size: 19 nm, according to ASTM D3849)

(7) Irganox® 1010 commercially available from BASF, an antioxidant

(8) 5-phenyltetrazole chemical foaming agent

(9) Pro-fax PD702 Polypropylene homopolymer commercially available from LyondellBasell

(10) LDPE 5004I, Low Density Polyethylene Resins commercially available from Dow™

(11) General Procedure for the Preparation of the Foam Material (FP)

(12) The different polymer compositions were compounded in ratios according to Table 1, Tables 2-3 and Table 4 below. Compounding into pellets was performed on a 26 mm twin screw extruder (Coperion ZSK-26) having an L/D ratio of 48:1. The base polymer pellets, elastomer(s), nucleating agent(s), filler(s), and additive(s) were fed into the feed throat of the extruder, and the extruder was set at a temperature of 305° C. (581° F.). The die temperature was set at 305° C. (581° F.) and a screw speed of 200 rpm was used along with a throughput rate of 40-50 lb/hr. The extrudate from the extruder in each case was cooled in a water trough and then pelletized. The pellets produced from the formulation were dried at temperatures between 80 and 85° C. (176-185° F.) for 4 hours. The compounded pellets were then dry blended with a masterbatch of 20 wt. % 5-phenyl tetrazole chemical foaming agent in polypropylene. The blend including polymer and foaming agent was fed to a foaming setup.

(13) Two foaming setups were used as described in the examples below.

Example 1

(14) Five compositions according to the invention (Ex1, Ex2, Ex3, Ex4, and Ex5) and one comparative composition (Ex6 C) have been prepared. Their composition weight ratios are reported in Table 1. Each composition was dry blended with a masterbatch of 20 wt. % 5-phenyl tetrazole chemical foaming agent in polypropylene, such that the final concentration of 5-phenyl tetrazole was about 0.09 wt. %.

(15) For examples Ex1-Ex6C, the foaming setup consisted of a 1.5-inch diameter Sterling single screw extruder with 4 heating/cooling zones and with an L/D ratio of 24:1, fitted with a 2 mm×65 mm slit die. The two rear heating zones were set to 282° C. (540° F.) and the two front heating zones were set to 299° C. (570° F.). The die temperature was set to 279° C. (535° F.).

(16) Density (kg/m.sup.3)

(17) The density was measured according to the D1622 ASTM method.

(18) The results are reported in Table 1.

(19) TABLE-US-00001 TABLE 1 Ex1 Ex2 Ex3 Ex4 Ex5 Ex6 C Composition (wt. %) PPS 78 88 89 79 74 99 Lotader ® 20 10 10 20 25 — AX8840 Carbon Black 1 1 — — — — Irganox ® 1 1 1 1 1 1 Density properties Foam density 737 ± 30 877 ± 64 1070 ± 7 1083 ± 10 1036 ± 52 1300 ± 6 (kg/m.sup.3) Density Reduction −41% −33% −13% −8% −12% −3%

(20) The specific compositions of Examples 1, 2, 3, 4, and 5, according to the invention, allow for producing foam materials with a density that is substantially reduced in comparison to foam material obtained from a composition having no elastomer (comparative example 6C). Examples 1 and 2 with carbon black (1 wt. %) show an even better density reduction.

Example 2

(21) Nine compositions according to the invention (Ex7 to Ex15) and six comparative compositions (Ex16C to Ex21C) have been prepared. Their composition weight ratios are reported in Tables 2-3. Each composition was dry blended with a masterbatch of 20 wt. % 5-phenyl tetrazole chemical foaming agent in polypropylene, such that the final concentration of 5-phenyl tetrazole was about 0.4 wt. %. The foaming setup consisted of an Intelli-Torque Plasti-Corder 1.5-mm diameter single screw extruder from C. W. Brabender Instruments, Inc. with an L/D ratio of 40:1. The extruder had 3 barrel heating/cooling zones and 2 die heating zones, and was fitted with a slit die with a 1″× 3/32″ opening. The rear and middle barrel heating zones were set to 277° C. and the front barrel heating zone was set 280° C. Both die heating zones were set to a temperature of 285° C.

(22) Density (kg/m.sup.3)

(23) The density was measured according to the D1622 ASTM method.

(24) Flexural Strain (%)

(25) The flexural strain was measured according to the D790 ASTM method. Test specimens were flexed up to 10% strain or until the specimens broke, whichever occurred first.

(26) Results for the average maximum flexural strain are reported in Tables 2-3. Note that reported flexural strains ≥10.00% indicate that the test resulted in zero broken test specimens for that composition.

(27) TABLE-US-00002 TABLE 2 Ex7 Ex8 Ex9 Ex10 Ex11 Ex12 Ex13 Ex14 Composition (wt. %) PPS 89 79 74 89 79 74 89 79 Lotader ® 10 20 25 — — — — — AX8840 Lotader ® — — — 10 20 25 — — AX8900 Elvaloy AS — — — — — — 10 20 Irganox ® 1 1 1 1 1 1 1 1 Foam properties Foam 767 806 824 564 852 853 821 858 density (kg/m.sup.3) Max Flexural 9.04 10.01 10.01 10.00 10.01 10.01 8.11 10.00 Strain (%)

(28) TABLE-US-00003 TABLE 3 Ex15 Ex16C Ex17C Ex18C Ex19C Ex20C Ex21C Composition (wt. %) PPS 74 89 79 74 89 79 74 Elvaloy AS 25 — — — — — — Pro-fax — 10 20 25 — — — Irganox ® 1 1 1 1 1 1 1 5004I — — — — 10 20 25 Foam properties Foam density 896 710 697 719 756 751 717 (kg/m.sup.3) Max Flexural 10.00 3.19 3.39 2.82 3.88 3.39 3.79 Strain (%)

Example 3

(29) Three compositions according to the invention (Ex22 to Ex24) and two comparative compositions (Ex25C and Ex26C) have been prepared. Their composition weight ratios are reported in Table 4. Each composition was dry blended with a masterbatch of 20 wt. % 5-phenyl tetrazole chemical foaming agent in polypropylene, such that the final concentration of 5-phenyl tetrazole was about 0.4 wt. %. The foaming setup consisted of an Intelli-Torque Plasti-Corder 1.5-mm diameter single screw extruder from C. W. Brabender Instruments, Inc. with an L/D ratio of 40:1. The extruder had 3 barrel heating/cooling zones and 2 die heating zones, and was fitted with a slit die with a 1″× 3/32″ opening. The rear and middle barrel heating zones were set to 277° C. and the front barrel heating zone was set 280° C. Both die heating zones were set to a temperature of 285° C.

(30) Density (kg/m.sup.3)

(31) The density was measured according to the D1622 ASTM method.

(32) Tensile Strain at Break (%)

(33) The tensile strain at break was measured according to the D638 ASTM method, on ASTM Type I tensile bars.

(34) The results are reported in Table 4 below.

(35) TABLE-US-00004 TABLE 4 Ex22 Ex23 Ex24 Ex25C Ex26C Composition (wt. %) PPS 74 74 74 74 74 AX8840 25 — — — — AX8900 — 25 — — — Elvaloy AS — — 25 — — Pro-fax — — — 25 — 5004I — — — — 25 Irganox ® 1 1 1 1 1 Foam properties Foam density 824 853 896 719 717 (kg/m.sup.3) Tensile strain 10.90 18.89 10.42 1.53 2.34 at break (%)