Temperature-Dependent Polymorphic Crystallization and Crystalline Structure of Unsaturated Polyesters Derived from cis-2-Butene-1,4-diol

作者：Yu, Yang; Zheng, Ying; Liang, Junhao; Sun, Xiaoli; Cao, Yan^*; Pan, Pengju^*; Wei, Zhiyong^*

来源：Macromolecules, 2022, 55(23): 10522-10533.

DOI：10.1021/acs.macromol.2c01698

• POLY(PROPYLENE FUMARATE)
• POLY(BUTYLENE ADIPATE)
• MECHANICAL-PROPERTIES
• PHASE-TRANSITION
• MOLECULAR-WEIGHT
• TRANSFORMATION
• FUNCTIONALIZATION
• ISODIMORPHISM
• DEGRADATION
• MORPHOLOGY

The poly(cis-butene dicarboxylate)s derived from cis-2-butene-1,4-diol and different diacids were synthesized, and their crystallization behavior and polymorphic structure were systematically investigated. The crystallization behavior of poly(cisbutene dicarboxylate)s depends on the number of methylene groups in polyester backbones. Poly(cis-butene pimelate) (PcBP) and poly(cis-butene azelate) (PcBAz) are semicrystalline, while poly(cis-butene glutarate) (PcBG) is amorphous. Particularly, PcBP can form distinct crystal modifications with varying crystallization temperatures (Tc). The alpha crystals are formed at Tc above 23 degrees C, while the beta crystals are formed at Tc below 10 degrees C. The mixed crystals of alpha- and beta-forms are generated at the intermediate temperature (10 <= Tc < 23 degrees C). The melting points of alpha crystals were higher than those of beta crystals, whereas the long period and crystalline thicknesses of alpha crystals were lower than those of beta crystals. The crystal structures of polymrophic PcBP were determined: the alpha polymorph has a monoclinic unit cell with the parameters a = 0.725 nm, b = 0.895 nm, c = 1.698 nm, and beta = 58.1 degrees, and the beta-form has a monoclinic unit cell with the parameters a = 0.839 nm, b = 0.965 nm, c = 1.670 nm, and beta = 64.5 degrees. The chain conformations in the alpha-form crystal are all-trans, whereas the conformation of beta-form chains deviates from the all-trans and owns skew CH2-CH2-OC(O) bonds (gauche bonds).

• 单位
  北京化工大学; 大连大学; y; 浙江大学