MONOVINYLIDENE AROMATIC POLYMERS CONTAINING NONFUNCTIONALIZED, NONMINERAL OIL
Monovinylidene aromatic polymers, e.g., general purpose polystyrene or high impact polystyrene, are plasticized with a nonfunctionalized, nonmineral oil, e.g., a vegetable oil such as canola oil, cottonseed oil or the like. The mixture of monovinylidene aromatic polymer and oil is typically and preferably free of any significant amount of functionalized nonmineral oil, and it typically contains at least 0.1 weight percent of the nonfunctionalized, nonmineral oil, alone or in combination with a mineral oil, based on the weight of the polymer. The nonmineral oil has an iodine value of less than 120, and a hydroxyl number of less than 20.
1 . A composition comprising (i) a monovinylidene aromatic polymer, and (ii) at least 0.1 weight percent, based on the weight of the polymer, of a plasticizer comprising a nonfunctionalized, nonmineral oil having an iodine value less than 120 and a hydroxyl number of less than 20, the plasticizer free of any significant amount of functionalized nonmineral oil.
2 . The composition of claim 1 in which the nonmineral oil is present in an amount of at least 0.5 weight percent based upon the weight of the polymer.
3 . The composition of claim 1 in which the nonmineral oil has an iodine value between 20 and 115.
4 . The composition of claim 1 in which the nonmineral oil comprises a vegetable oil.
5 . The composition of claim 4 in which the plasticizer further comprises a mineral oil.
6 . The composition of claim 5 in which the nonmineral oil comprises 50 or more wt % of the plasticizer.
7 . The composition of claim 6 in which the vegetable oil comprises oil derived from at least one of peanuts, cottonseed, olives, rapeseed, high-oleic sunflower, palm and corn.
8 . The composition of claim 1 in which the polymer comprises units derived from a monovinylidene aromatic monomer of the formula:
in which R′ is hydrogen or methyl, and Ar is an aromatic ring structure having from 1 to 3 aromatic rings.
9 . The composition of claim 8 in which Ar is phenyl or alkylphenyl, and the alkyl group of the phenyl ring contains 1 to 10 carbon atoms.
10 . The composition of claim 9 in which the alkyl group of the phenyl ring contains 1 to 4 carbon atoms.
11 . The composition of claim 1 in which the monovinylidene aromatic polymer is blended or grafted with at least one rubber.
12 . The composition of claim 11 in which the rubber has a glass transition temperature of not greater than 0° C.
13 . The composition of claim 11 in which the rubber is selected from the group consisting of diene rubbers, diene block rubbers, butyl rubbers, ethylene propylene rubbers, ethylene-propylene-diene monomer rubbers, ethylene copolymer rubbers, acrylate rubbers, polyisoprene rubbers, halogen-containing rubbers and silicone rubbers.
14 . The composition of claim 11 in which the rubber is present in an amount of less than 40 weight percent based upon the weight of the polymer.
15 . The composition of claim 8 in which the polymer is general purpose polystyrene.
16 . The composition of claim 11 in which the polymer is high impact polystyrene.
17 . The composition of claim 11 in which the polymer is ABS.
18 . The composition of claim 8 in which the polymer is SAN.
19 . An article prepared from the composition of claim 1 .
20 . The article of claim 20 formed from extrusion, molding or thermoforming.
21 . The composition of claim 1 formed by polymerizing monovinylidene aromatic monomers in the presence of a plasticizer comprising the nonfunctional, nonmineral oil.