Phase Transition and Side-Chain Crystallization of Poly(methyl vinyl ether-alt-maleic anhydride)-g-Alkyl Alcohol Comb-like Polymers

A series of poly(methyl vinyl ether- alt -maleic anhydride)- g -alkyl alcohol (PVEM -C n ) comb-like polymers were synthesized by a simple esterification reaction between poly(methyl vinyl ether- alt -maleic anhydride) and n -alkyl alcohol with n = 14–26. Thermal property, side-chain crystallization, and phase transition behavior of PVEM-C n comb-like polymers were investigated by 1 H NMR,DSC, variable-temperature X-ray scattering and FTIR, as well as solid-state 13 C CP/MAS NMR. Obvious side-chain crystallization behavior from the pended side chains onto the PVEM backbone is well confirmed. With the side-chain length increasing from 14 to 26, phase transition temperature and melting enthalpy both increase from 30.1 to 79.4 °C and from 17.1 to 55.0 kJ/mol, respectively, and the crystallizable carbon atoms ( N c ) also vary from N c = 5.6 to 17.7 accordingly. Regular trans conformation state first transforming into irregular trans conformational disordered one and then to gauche state is well demonstrated, and the chain packing manners of orthorhombic and hexagonal show a size-dependent phenomenon. Comparison of the phase transition behavior and chain packing structure for the single-component and the two-component polymer backbone comb-like polymers is approached. And, the influence of chemical junction on the side-chain crystallization behavior is also discussed from the aspect of molecular chain packing and crystallization behavior.