Method to produce flame retardant styrenic polymers and product produced thereby
AssigneeMarquette University
InventorsCharles A. Wilkie, Jin Zhu, Hongyang Yao, Michael A. McKinney
Life of this patent
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Abstract
Disclosed is a process for producing thermally stabilized styrenic polymers and products produced thereby wherein a pre-formed styrenic polymer is functionalized with a bifunctional Friedel-Crafts-type alkylation or acylation agent to yield a functionalized styrenic polymer. The functionalized polymer is admixed with a Friedel-Crafts-type catalyst, preferably a phosphate ester, and optionally a base, such that the functionalized polymer will experience inter- and intramolecular cross-linking reactions at elevated temperatures, thereby stabilizing the polymer from further thermal degradation.
Claims35
A method of imparting increased thermal stability to styrenic polymers comprising:
- (a) reacting a pre-formed styrenic polymer with a bifunctional cross-linking reagent selected from the group consisting of:
- X—R—Y
- wherein R is an aromatic linking group;
- and
- X and Y are independently selected from the group consisting of halo, hydroxy, nitro, alkyl, alkenyl, haloalkyl, hydroxyalkyl, alkyloxy, alkyloxyalkyl, alkylcarbonyl, alkylcarbonylalkyl, alkyloxycarbonyl, alkyloxycarbonylalkyl, alkylcarboxy, alkylcarboxyalkyl, C1 to C6 dicarboxylates, substituted or unsubstituted phenyl or naphthyl, benzoate, mononitrobenzoate, polynitrobenzoate, phosphate, alkylphosphate, phenylphosphate, diphenylphosphate, alkyl-diaryl-phosphate, carbonate, phenyl carbonate, inorganic acid esters, mesylate, and tosylate, at a first temperature wherein one of X or Y reacts with aromatic moieties in the pre-formed styrenic polymer to yield a functionalized styrenic polymer;
- and then
- (b) admixing the functionalized styrenic polymer with an acid catalyst capable of catalyzing Friedel-Crafts alkylation or acylation reactions, which thereby catalyzes reaction of the other of X or Y with remaining aromatic moieties in the functionalized polymer as a second temperature, wherein the second temperature is higher than the first temperature.
A method of imparting increased thermal stability to styrenic polymers comprising:
- (a) reacting a pre-formed styrenic polymer with a bifunctional cross-linking reagent selected from the group consisting of:
- wherein X and Y are independently selected from the group consisting of hydrogen, halo, hydroxy, nitro, alkyl, alkenyl, haloalkyl, hydroxyalkyl, alkyloxy, alkyloxyalkyl, alkylcarbonyl, alkylcarbonylalkyl, alkyloxycarbonyl, alkyloxycarbonylalkyl, alkylcarboxy, alkylcarboxyalkyl, substituted or unsubstituted phenyl or naphthyl (wherein the substitution is selected from the group consisting of halo, hydroxy, nitro, alkyl, alkenyl, haloalkyl), benzoate, nitrobenzoate, phosphate, alkylphosphate, phenylphosphate, diphenylphosphate, alkyl-diaryl-phosphate, carbonate, phenyl carbonate, inorganic acid esters, mesylate, and tosylate, at a first temperature wherein one of X or Y reacts with aromatic moieties in the pre-formed styrenic polymer to yield a functionalized styrenic polymer;
- and then
- (b) admixing the functionalized styrenic polymer with an acid catalyst capable of catalyzing Friedel-Crafts alkylation or acylation reactions, which thereby catalyzes reaction of the other of X or Y with remaining aromatic moieties in the functionalized polymer as a second temperature, wherein the second temperature is higher than the first temperature.
Dependencies are inferred from the claim text.