Synthesis and thermal analysis of linear triblock copolymers based on methacrylate ester

Two linear triblock copolymers poly(t-butyl methacrylate-b-2-hydroxyl ethyl methacrylate-b-N,N-dimethylaminoethyl methacrylate) (PtBMA₉₇-b-PHEMA₁₈-b-PDMAEMA₉₈) and poly(t-butyl methacrylate-b-glycidyl methacrylate-b-styrene) (PtBMA₁₃₇-b-PGMA₂₃-b-PSt₁₅₆) were controlled synthesized with living RAFT polymerization technique under the chain transfer of cumyl dithiobenzoate. The results of FT-IR spectra illustrate that the characteristic groups of copolymer fit well with the result of ¹H-NMR, which successfully determines the corresponding molecular structure of triblock copolymers. The thermal stability of PtBMA-b-PGMA-b-PSt and PtBMA-b-PHEMA-b-PDMAEMA was also complementarily explained by the activation energy of thermal decomposition from Friedman differential method and Ozawa–Flynn–Wall integral method. The results show that the degradation energy of the former copolymer was much higher than that of the latter copolymer, because the aromatic groups were introduced into the polymer segments of the former copolymer during the RAFT polymerization process, and the other reason is the oxirane rings are typically reactive which they occurred intermolecular crosslinking reaction during the thermal decomposition.