Abstract: A series of polyesters, poly(butylene succinate-co-butylene 2,2-dimethyl succinate) (PBS-2M), were obtained from the polycondensation of succinate and/or 2,2-dimethyl succinate with 1,4-butanediol. The compositions and physical properties of the resulted homo- and co-polyesters were investigated by 1H-NMR, differential scanning calorimetry, and X-ray diffraction. The results suggested that the introduction of comonomer containing 2,2-dimethyl side-group led to a change in thermal properties and crystallization behavior. The equilibrium melting temperature obtained by the Hoffman-Weeks plot significantly decreased with increasing concentration of comonomers containing two symmetrical methyl side-groups. Furthermore, Avrami method was used to analyze the kinetics of isothermal crystallization of PBS and PBS-2M-20. The Avrami exponents estimated using Avrami plots, ranging from 2.8 to 3.0 for PBS and 2.6 to 2.8 for PBS-2M-20, indicating that the mechanism of crystallization for both homo- and co-polyester was a tri-dimensional growth with heterogeneous nucleation. Meanwhile, X-ray diffraction showed that there was almost no effect of the 2,2-dimethyl succinate unit on the crystal structure.

Key words: Poly(butylene succinate-co-butylene 2, 2-dimethyl succinate), Thermal property, Isothermal crystallization kinetics