Collagen is a natural polymer that cannot be applied freely to specific end uses due to its inherent drawbacks. Grafting polymerization of methyl methacrylate-co-ethyl acrylate was applied to modify the surface of acid soluble collagen (ASC). The main objective of this work is not only reducing the hydrophilic behavior of collagen on which has been concentrated so far but also successfully showed that the introduced co-monomers onto ASC can alter the thermal behavior of the resulted copolymer. The level of branched copolymer significantly influenced the initial viscosity in studied co-monomer feed ratios. The graft polymerization of collagen demonstrated the meaningful change in conductivity value of branched copolymer, where the copolymer in side chain with low dielectric constant covalently bonded onto the ASC. The increase in the co-monomer feed ratio had no significant effect on conductivity value of copolymer, afterwards. The novelty of this work was determined to achieve the new copolymer onto the backbone of collagen to be used in specific thermally stabled end uses that the sufficient chain entanglements improve the flexibility of final product. POLYM. ENG. SCI., 58:1261-1267, 2018. (c) 2017 Society of Plastics Engineers