Copolymerization of poly (vinyl alcohol)-graft-poly (1, 4-dioxan-2-one) with designed molecular structure by a solid-state polymerization method
作者：SC Chen, XL Wang, KK Yang, G Wu, YZ Wang
關(guān)鍵字：biodegradable, solid-state polymerization, graft copolymer, poly(vinyl alcohol), poly(1,4-dioxan-2-one)
論文來源：期刊
具體來源：Journal of Polymer Science Part A: Polymer Chemistry
發(fā)表時(shí)間：2006年
Poly(vinyl alcohol)-graft-poly(1,4-dioxan-2-one) (PVA-g-PPDO) with designed molecular structure was synthesized by a solid-state polymerization. The solid-state copolymerization was preceded by a graft copolymerization of PDO initiated with PVA as a multifunctional initiator, and Sn(Oct)(2) as a coininitiator/catalyst in a homogeneous molten state. The polymerization temperature was then decreased and the copolymerization was carried out in a solid state. The products prepared by solidstate polymerization were characterized by H-1 NMR and DSC, and were compared with those synthesized in the homogeneous molten state. The degree of polymerization (D-p), degree of substitution (D-s), yield and the average molecular weight of the graft copolymer with different molecular structure were calculated from the H-1 NMR spectra. The results show that the crystallization process during the solid-state polymerization may suppress the undesirable inter- or intramolecular side reactions, then resulting in a controlled molecular structure of PVA-g-PPDO. The results of DSC measurement show that the molecular structures determine the thermal behavior of the PVA-g-PPDO.