Method of preparing polymer

Abstract

The present disclosure relates to a method of preparing a polymer, which includes: adding an alkyl-substituted aromatic vinyl-based monomer and a vinyl cyanide-based monomer to a reactor and initiating polymerization; and performing polymerization while continuously adding an alkyl-substituted aromatic vinyl-based monomer and a multifunctional initiator to the reactor, wherein the continuous addition of the alkyl-substituted aromatic vinyl-based monomer and the multifunctional initiator is initiated when a polymerization conversion rate is 10 to 30%, and the continuous addition of the alkyl-substituted aromatic vinyl-based monomer and the multifunctional initiator is terminated when a polymerization conversion rate is 70 to 80%.

Dependencies are inferred from the claim text.