FLAME-RETARDANT COPOLYMERS AND MOLDING COMPOUNDS

Abstract

The invention relates to copolymers and molding compounds having reactively bonded sulfur and an overall low sulfur content. The copolymers and molding compounds of the invention are substantially colorless and odorless while sufficiently flame-retardant and can be used in the building industry and electrical industry.

Claims

1. A fire-retardant copolymer according to formula (1) having a random monomer distribution ##STR00014## where R.sub.1 to R.sub.4 are equal, or at least one or more R.sub.1 to R.sub.4 are different from each other and R.sub.1, R.sub.2, R.sub.3, R.sub.4 are selected from groups a) to c) having the substituents, a) aryl, cyclohexyl, arylphosphatyl, arylphosphinyl, arylphosphonyl, arylphosphineoxidyl, cyclotriphosphazenyl, polyphosphazenyl, C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.2-C.sub.18-alkynyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.10-cycloalkyl, C.sub.6-C.sub.12-aryl-C.sub.1-C.sub.18-aryl, a heteroaryl group containing one or more heteroatoms from the group N, O, P and S, O—(C.sub.1-C.sub.18)-alkyl, O—(C.sub.2-C.sub.18)-alkenyl, O—(C.sub.2-C.sub.18)-alkynyl, O—(C.sub.6)-aryl, O—(C.sub.6-C.sub.12)-aryl, O—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-O, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-O, N—(C.sub.1-C.sub.18)-alkyl, N—(C.sub.2-C.sub.18)-alkenyl, N—(C.sub.2-C.sub.18)-alkynyl, N—(C.sub.6)-aryl, N—(C.sub.6-C.sub.12)-aryl, N—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-N, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-N, S—(C.sub.1-C.sub.18)-alkyl, S—(C.sub.1-C.sub.18)-alkenyl, S—(C.sub.2-C.sub.12)-alkynyl, S—(C.sub.6)-aryl, S—(C.sub.6-C.sub.12)-aryl, S—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-S, (C.sub.6-C.sub.12)-aryl-(C.sub.6-C.sub.12)-alkyl-S, P—(C.sub.1-C.sub.18)-alkyl, P—(C.sub.2-C.sub.18)-alkenyl, P—(C.sub.2-C.sub.18)-alkynyl, P—(C.sub.6)-aryl, P—(C.sub.6-C.sub.12)-aryl, P—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-P, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-P, OH, F, Cl, Br, H; b) of formula (2) ##STR00015## where R.sub.5 to R.sub.9 are equal or different from each other, comprising aryl, cyclohexyl, arylphosphatyl, arylphosphinyl, arylphosphonyl, arylphosphineoxidyl, cyclotriphosphazenyl, polyphosphazenyl, C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.2-C.sub.18-alkynyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.10-cycloalkyl, C.sub.6-C.sub.12-aryl-C.sub.1-C.sub.18-alkyl, a heteroaryl group containing one or more heteroatoms from the group N, O, P and S, O—(C.sub.1-C.sub.18)-alkyl, O—(C.sub.2-C.sub.18)-alkenyl, O—(C.sub.2-C.sub.18)-alkynyl, O—(C.sub.6)-aryl, O—(C.sub.6-C.sub.12)-aryl, O—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-O, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-O, N—(C.sub.1-C.sub.18)-alkyl, N—(C.sub.2-C.sub.18)-alkenyl, N—(C.sub.2-C.sub.18)-alkynyl, N—(C.sub.6)-aryl, N—(C.sub.6-C.sub.12)-aryl, N—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-N, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-N, S—(C.sub.1-C.sub.18)-alkyl, S—(C.sub.1-C.sub.18)-alkenyl, S—(C.sub.2-C.sub.12)-alkynyl, S—(C.sub.6)-aryl, S—(C.sub.6-C.sub.12)-aryl, S—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-S, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-S, P—(C.sub.1-C.sub.18)-alkyl, P—(C.sub.2-C.sub.18)-alkenyl, P—(C.sub.2-C.sub.18)-alkynyl, P—(C.sub.6)-aryl, P—(C.sub.6-C.sub.12)-aryl, P—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-P, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-P, OH, F, Cl, Br, H, compounds of formula (3) ##STR00016## compounds of formula (4) ##STR00017## compounds of formula (5) ##STR00018## where R.sub.10 to R.sub.15 are equal or different from each other, comprising C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.2-C.sub.18-alkynyl, C.sub.6-aryl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.10-cycloalkyl, C.sub.6-aryl C.sub.1-C.sub.18-alkyl, C.sub.6-C.sub.12-aryl-C.sub.1-C.sub.18-alkyl, a heteroaryl group containing one or more heteroatoms from the group N, O, P and S, O—(C.sub.1-C.sub.18)-alkyl, O—(C.sub.2-C.sub.18)-alkenyl, O—(C.sub.2-C.sub.18)-alkynyl, O—(C.sub.6)-aryl, O—(C.sub.6-C.sub.12)-aryl, O—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-O, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-O, N—(C.sub.1-C.sub.18)-alkyl, N—(C.sub.2-C.sub.18)-alkenyl, N—(C.sub.2-C.sub.18)-alkynyl, N—(C.sub.6)-aryl, N—(C.sub.6-C.sub.12)-aryl, N—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-N, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-N, S—(C.sub.1-C.sub.18)-alkyl, S—(C.sub.1-C.sub.18)-alkenyl, S—(C.sub.2-C.sub.12)-alkynyl, S—(C.sub.6-C.sub.12)-aryl, S—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-S, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-S, P—(C.sub.1-C.sub.18)-alkyl, P—(C.sub.2-C.sub.18)-alkenyl, P—(C.sub.2-C.sub.18)-alkynyl, P—(C.sub.6)-aryl, P—(C.sub.6-C.sub.12)-aryl, P—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-P, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-P, OH, F, Cl, Br, H; c) of formula 6, ##STR00019## where R.sub.16 to R.sub.20 are equal or different from each other, comprising C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.2-C.sub.18-alkynyl, C.sub.6-aryl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.10-cycloalkyl, C.sub.6-aryl-C.sub.1-C.sub.18-alkyl, C.sub.6-C.sub.12-aryl-C.sub.1-C.sub.18-alkyl, a heteroaryl group containing one or more heteroatoms from the group N, O, P and S, O—(C.sub.1-C.sub.18)-alkyl, O—(C.sub.2-C.sub.18)-alkenyl, O—(C.sub.2-C.sub.18)-alkynyl, O—(C.sub.6)-aryl, O—(C.sub.6-C.sub.12)-aryl, O—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-O, (C.sub.6-C.sub.12)-aryl)-(C.sub.1-C.sub.18)-alkyl-O, N—(C.sub.1-C.sub.18)-alkyl, N—(C.sub.2-C.sub.18)-alkenyl, N—(C.sub.2-C.sub.18)-alkynyl, N—(C.sub.6)-aryl, N—(C.sub.6-C.sub.12)-aryl, N—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-N, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-N, S—(C.sub.1-C.sub.18)-alkyl, S—(C.sub.1-C.sub.18)-alkenyl, S—(C.sub.2-C.sub.12)-alkynyl, S—(C.sub.6-C.sub.12)-aryl, S—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-S, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-S, P—(C.sub.1-C.sub.18)-alkyl, P—(C.sub.2-C.sub.18)-alkenyl, P—(C.sub.2-C.sub.18)-alkynyl, P—(C.sub.6)-aryl, P—(C.sub.6-C.sub.12)-aryl, P—(C.sub.3-C.sub.10)-cycloalkyl, (C.sub.6)-aryl-(C.sub.1-C.sub.18)-alkyl-P, (C.sub.6-C.sub.12)-aryl-(C.sub.1-C.sub.18)-alkyl-P, OH, F, Cl, Br, H; wherein n.sub.1=1-100,000 n.sub.2=0-10,000 n.sub.3=0-10,000 n.sub.4=0-10,000 n.sub.5=0-10,000 n.sub.6=0-10,000 n.sub.7=0-10,000 n.sub.8=0-10,000 n.sub.9=0-10,000 and the sulfur content is ≤10% within the flame-retardant copolymer.

2. The fire-retardant copolymer according to claim 1, wherein the copolymer is colorless and/or odorless and the colorlessness is determined on a color scale according to RAL 1013 Oyster white, RAL 9001 Cream, RAL 9003 Signal white, RAL 9010 Pure white and/or RAL 9016 Traffic white and/or the odorlessness is within the detection limit of sulfide compounds within the range of less than 5 μg/m.sup.3 of air.

3. The fire-retardant copolymer according to claim 1, wherein the copolymer is self-extinguishing.

4. The fire-retardant copolymer according to claim 1, wherein n.sub.1=1-1000 n.sub.2=0-500 n.sub.3=0-1 n.sub.4=0-500 n.sub.5=0-1 n.sub.6=0-500 n.sub.7=0-1 n.sub.8=0-500 n.sub.9=0-1.

5. The fire-retardant copolymer according to claim 1, having the formula (7) ##STR00020## wherein R.sub.21 to R.sub.25 are equal or different and comprise a polymer according to formula (1) and/or a substituent of the allyloxy (C.sub.3H.sub.6O) type wherein n.sub.1=1-1000 n.sub.2=1-500 n.sub.3=0-1 n.sub.4=1-500 n.sub.5=0-1.

6. The fire-retardant copolymer according to claim 1, having the formula (8) ##STR00021## wherein n.sub.1=1-1000 n.sub.2=1-500 n.sub.3=0.

7. The fire-retardant copolymer according to claim 1, as a component of a molding compound for extrusion or polymerization, wherein the molding compound contains phosphorus-containing additives, in particular 2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5]undecane-3,9-dimethyl-3,9-dioxide (0.1-10% by weight) or hexaphenoxycyclotriphosphazene (0.5-20% by weight).

8. The fire-retardant copolymer according to claim 1, as a component of a molding compound made from homopolymeric polystyrene (PS) or expandable styrene polymers (EPS) or extruded foam sheets (XPS).

9. A fire-retardant molding compound for polymerization or extrusion having at least one fire-retardant copolymer of formula (7) ##STR00022## wherein R.sub.21 to R.sub.25 are equal or different and comprise a polymer according to formula (1) and/or a substituent of the allyloxy (C.sub.3H.sub.6O) type wherein n.sub.1=1-1000 n.sub.2=1-500 n.sub.3=0-1 n.sub.4=1-500 n.sub.5=0-1, having a statistical monomer distribution and a sulfur content of less than 10% by weight and wherein the fire-retardant molding compound comprises a polymer other than the fire-retardant copolymer.

10. The fire-retardant molding compound for polymerization or extrusion according to claim 9, wherein the further polymer comprises polystyrene.

11. The fire-retardant molding compound for polymerization or extrusion according to claim 9, wherein the fire-retardant copolymer comprises at least one compound of a copolymer having the formula (8) ##STR00023## wherein n.sub.1=1-1000 n.sub.2=1-500 n.sub.3=0, Is.

12. The fire-retardant molding compound for polymerization or extrusion according to claim 11, wherein the molding compound is self-extinguishing.

13. The fire-retardant molding compound for polymerization or extrusion according to claim 9, wherein the polymerized or extruded molding compound is colorless and/or odorless.

14. The fire-retardant molding compound according to claim 9, wherein the molding compound contains at least one IR absorber, in particular graphite, carbon black or aluminum having an average particle size within the range from 1 to 50 μm.

15. The fire-preventing molding compound according to claim 9, wherein molding materials produced with the molding composition, in particular the foams, have a density of 5 to 150 kg/m.sup.3.

16. A method for producing molding compounds according to claim 9, comprising the steps: a. mixing an organic blowing agent into a polymer melt comprising at least one fire-retardant copolymer having or not having phosphorus-containing additives by means of static and/or dynamic mixers at a temperature of at least 150° C., b. cooling the blowing agent-containing polymer melt to a temperature of at least 120° C., c. discharging through a nozzle plate having holes whose diameter at the nozzle outlet is at most 1.5 mm and d. granulating the blowing agent-containing melt directly behind the nozzle plate under water at a pressure within the range of 1 to 20 bar.

17. A method for producing molding compounds according to claim 9, comprising the steps: a. polymerization, b. adding an organic blowing agent before, during and/or after the polymerization and c. separating the expandable, blowing agent-containing copolymers by means of sieving.

18. A method for producing molding compounds according to claim 9, wherein the molding compounds are obtained by means of a suspension polymerization.

19. Use of fire-retardant copolymers according to claim 5 as an individual or co-component of insulating material for buildings or as a structural part and component in the electrical and electronics sector.

20. Use of fire-retardant copolymers according to claim 5, wherein the copolymers are halogen-free.

Description

EXAMPLES

Syntheses:

Materials Used:

[0067] Styrene (99%, Acros Organics/catalyst removed), sulfur (>99%, Alfa Aesar), divinylbenzene (Merck KGaA, contains 25-50% ethyl styrene) and hexakisallyloxycyclotriphosphazene (synthetically accessible according to M. Dutkiewicz et al., Polymer Degradation and Stability 2018, 148, 10-18) were used for the syntheses carried out.

Copolymer CP1: poly-S(1%)-sty(99%)

##STR00010##

where
n.sub.1=1-1000
n.sub.2=0-500
n.sub.3=0-1.

[0068] Sulfur (50 mg, 1% by weight) and styrene (4950 mg, 99% by weight) were mixed together and deoxygenated by means of three freeze-thaw cycles. The mixture was heated at 130° C. for 72 hours. After dissolving in tetrahydrofuran (THF), the product was isolated by means of precipitation in methanol.

EA: C (%)=91.6; H (%)=7.69; S (%)=0.86;

TGA: Td.SUB.5% .(° C.)=367;

DSC: T.SUB.g.(° C.)=95;

[0069] GPS: M.sub.w(kDa)=48; M.sub.n (kDa)=20.
Copolymer CP2: poly-S(0.5%)-sty(99.5%)

##STR00011##

where n.sub.1=1-1000
n.sub.2=0-500
n.sub.3=0-1.

[0070] Sulfur (25 mg, 0.5% by weight) and styrene (4975 mg, 99.5% by weight) were mixed together and deoxygenated by means of three freeze-thaw cycles. The mixture was heated at 130° C. for 72 hours. After dissolving in THF, the product was isolated by means of precipitation in methanol.

EA: C (%)=92.0; H (%)=7.67; S (%)=0.47;

TGA: Td.SUB.5% .(° C.)=375;

DSC: T.SUB.g.(° C.)=101;

[0071] GPS: M.sub.w(kDa)=128; M.sub.n(kDa)=66;

[0072] Copolymer CP3: poly-S(1%)-sty(98%)-DVB(1%)

##STR00012##

wherein
n.sub.1=1-1000
n.sub.2=0-500
n.sub.3=0-1
n.sub.4=0-500
n.sub.5=0-1 and
wherein R.sub.27 comprises
a polymer according to formula (1) or
a substituent of the vinyl type, in each case in an ortho, meta or para position relative to the monomer chain.

[0073] Sulfur (50 mg, 1% by weight), styrene (4900 mg, 98% by weight) and divinylbenzene (50 mg, 1% by weight) were mixed together and deoxygenated by means of three freeze-thaw cycles. The mixture was heated at 130° C. for 72 hours. After dissolving in THF, the product was isolated by means of precipitation in methanol.

EA: C (%)=91.7; H (%)=8.20;

TGA: Td.SUB.5% .(° C.)=343;

DSC: T.SUB.g.(° C.)=93;

[0074] GPS: M.sub.w(kDa)=387; M.sub.n (KDa)=18;
Copolymer CP4 poly-S(1)-sty(96)-CTP(3)

##STR00013##

where
n.sub.1=1-1000
n.sub.2=0-500
n.sub.3=0-1
n.sub.4=0-500
n.sub.5=0-1 and
R.sub.21 to R.sub.25 are equal or different and comprise
a polymer according to formula (1) and/or
a substituent of the allyloxy (C.sub.3H.sub.6O) type.

[0075] Sulfur (50 mg, 1% by weight), styrene (4800 mg, 96% by weight) and hexakisallyloxycyclotriphosphazene (150 mg, 3% by weight) were mixed together and deoxygenated by means of three freeze-thaw cycles. The mixture was heated at 130° C. for 72 hours. After dissolving in THF, the product was isolated by means of precipitation in methanol.

EA: C (%)=90.5; H (%)=8.18; S (%)=0.23; N (%)=0.24;

TGA: Td.SUB.5% .(° C.)=304;

DSC: T.SUB.g.(° C.)=82;

[0076] GPS: M.sub.w(kDa)=70; M.sub.n(kDa)=32.

[0077] Polymers and additives used for producing fire-retardant molding compounds:

TABLE-US-00001 Polymer/additive Type and manufacturer Abbreviation Polystyrene Polystyrene 158K, BASF PS SE, Ludwigshafen, Germany 2,4,8,10-tetraoxa-3,9-diphosphaspiro aflammite PCO 900, Thor P1 [5.5] undecane-3,9-dimethyl-3,9-dioxides GmbH, Speyer, Germany hexaphenoxycyclotriphosphazenes abcr GmbH, Karlsruhe, P2 Germany

[0078] Production of the Fire Test Specimens

[0079] VB1 and VB4:

[0080] First, 20 g of PS were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried polymer was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0081] VB2 and VB5:

[0082] First, 20 g of PS and 0.5 g of P1 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried compound was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0083] VB3 and VB6:

[0084] First, 20 g of PS and 0.95 g of P2 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried compound was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0085] EB1:

[0086] First, 20 g of CP1 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried copolymer was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0087] EB2 and EB7:

[0088] First, 20 g of CP1 and 0.95 g of P2 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried compound was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0089] EB3:

[0090] First, 20 g of CP2 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried copolymer was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0091] EB4:

[0092] First, 20 g of CP2 and 0.5 g of P1 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried compound was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0093] EB5 and EB8:

[0094] First, 20 g of CP3 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried copolymer was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0095] EB6 and EB9:

[0096] First, 20 g of CP4 were dissolved in dichloromethane. The solution was then poured into a 20 cm×10 cm aluminum mold and dried at room temperature (RT) for 24 hours. The dried copolymer was removed from the aluminum mold and foamed with water vapor in a perforated stainless steel mold for 20 minutes. The foamed test body was dried to constant mass for 24 hours at 50° C. The resulting test bodies have a density of approx. 70 kg/m.sup.3.

[0097] Carrying Out the Fire Tests

[0098] Screening Test:

[0099] A 5 cm×10 cm×1 cm strip of the foam body was held for a few seconds in a 2 cm high propane gas flame having an energy of approx. 50 kW. As soon as the sample ignited, but after a maximum of 5 seconds, it was pulled out of the flame and the ignitability and self-extinguishing of the sample were recorded. Self-extinguishing is understood to mean the following behavior in the screening test: The specimen ignited by the flame of the burner extinguishes within 5 seconds after the burner flame has been removed from the specimen.

[0100] Fire Test According to DIN 4102-2 (B2):

[0101] A 20 cm×10 cm×1 cm sample was exposed to a flame having an energy of approx. 50 kW and a flame height of 2 cm at a vertical distance of 1 cm from the underside of the sample for 15 seconds. The afterburn time, flame height, self-extinguishing and burning dripping behavior of the sample were noted.

[0102] Elemental Analysis:

[0103] The elemental composition of the samples was measured using a vario MICRO cube (Elementar Analysesysteme GmbH, Langenselbold). The measurement method was calibrated with sulfanilamide.

[0104] Gel Permeation Chromatography:

[0105] The molecular weight and the molecular weight distribution of the samples were measured with a GPC analysis system from Shimadzu (Kyoto, Japan) consisting of a degasser (DGU-20A3R), two pumps (LC-20AD), an autosampler (SIL-20A.sub.HT), a column oven (CTO-20A, 30° C.), a diode array detector (SPD-M20A, 30° C.), a refractive index detector (RID-20A, 30° C.), a control unit (CBM-20A) and a column set (PSS Polymer Standard Services GmbH, Mainz—a pre-column SDV 50×8 mm, 5 μm, two separation columns SDV 300×8 mm, 5 μm, 1000 Å, one separation column SDV 300×8 mm, 5 μm, 100,000 Å). Calibration was performed using polystyrene standards.

[0106] The elemental composition, molecular weights and distributions, and thermal characteristics of the synthesized copolymers are shown in Tables 1 and 2 below.

TABLE-US-00002 TABLE 1 Elementary composition of the synthesized copolymers: Sample C (%).sup.1 H (%).sup.1 S (%).sup.1 N (%).sup.1 PS 92.3.sup.2 7.74.sup.2 0.00.sup.2 0.00.sup.2 CP1 91.6 7.69 0.86 0.00 CP2 92.0 7.67 0.47 0.00 CP3 91.7 8.20 0.00 0.00 CP4 90.5 8.18 0.23 0.24 .sup.1percentage-based elemental composition determined by means of elemental analysis, .sup.2theoretically calculated value

TABLE-US-00003 TABLE 2 Molecular weights and distributions and thermal characteristics of the copolymers: Sample Mn.sup.1 (kDa) Mw.sup.1 (kDa) D.sup.1 Td.sub.5%.sup.2 (° C.) Tg.sup.3 (° C.) PS 144 257 1.78 386 101 CP1 20 48 2.36 367 95 CP2 66 128 1.93 375 101 CP3 18 387 20.98 343 93 CP4 32 70 2.19 304 82 .sup.1average molecular weights and their molecular weight distribution determined by means of GPC, .sup.2decomposition temperature at 5% mass loss determined by means of TGA, .sup.3onset of glass transition temperature determined by means of DSC.

[0107] Fire Test Results:

[0108] A. Screening Test:

TABLE-US-00004 TABLE 3 Content of Content of Self- (co)polymer P1 or P2 extinguishing Example Composition (phr.sup.1) (phr.sup.1) (yes/no) VB1 PS 100 — no VB2 PS + P1 100 2.50 no VB3 PS + P2 100 4.75 no EB1 CP1 100 — yes EB2 CP1 + P2  100 4.75 yes EB3 CP2 100 — no EB4 CP2 + P1  100 2.50 yes EB5 CP3 100 — no EB6 CP4 100 — yes .sup.1parts per hundred rubber

[0109] B. Small Burner Test According to DIN 4102-2 (B32):

TABLE-US-00005 TABLE 4 Content of Content of Flame Afterburn (co)polymer P1 or P2 height time Example Composition (phr.sup.1) (phr.sup.1) (cm) (s) VB4 PS 100 — >15 31 VB5 PS + P1 100 2.50 >15 35 VB6 PS + P2 100 4.75 >15 22 EB7 CP1 + P2  100 4.75 9 0 EB8 CP3 100 — >15 23 EB9 CP4 100 — 12 12.8 .sup.1parts per hundred rubber