Laboratoire de Chimie, Catalyse, Polymères et Procédés (C2P2) - LCPP Group, Université de Lyon, Univ. Lyon 1, CPE Lyon, CNRS, UMR 5265, Villeurbanne, France.
Biomacromolecules. 2020 Dec 14;21(12):4747-4760. doi: 10.1021/acs.biomac.0c00910. Epub 2020 Oct 9.
The feasibility of co- and terpolymerizing vinylidene fluoride (VDF) with ethylene (C2) and/or vinyl acetate in an emulsion polymerization process was studied for different C2 pressures, initiator concentration, surfactant concentration, pH, C2 injection protocols, and the influence of vinyl acetate (VAc) in the reaction medium. Pressure drop and temperature profiles as well as gravimetry were used to follow the rate of polymerization. The microstructure of the synthesized products was assessed by fluorine and hydrogen nuclear magnetic resonance spectroscopy (19F and 1H NMR). C2 was found to cause an inhibition/retardation effect on the copolymerization with VDF (and with VDF/VAc). However, statistical copolymers containing VAc and VDF were synthesized by reducing as much as possible the homogeneous nucleation of the VAc in the water phase. This was done by adding VAc into the reaction after the homogeneous-coagulative nucleation of VDF takes place (around 5 min after initiator injection).
研究了在乳液聚合过程中，不同的 C2 压力、引发剂浓度、表面活性剂浓度、pH 值、C2 注入方案以及反应介质中醋酸乙烯酯 (VAc) 的影响下，乙烯 (C2) 和/或醋酸乙烯酯与偏二氟乙烯 (VDF) 共聚和三元共聚的可行性。压降和温度曲线以及重量分析用于跟踪聚合速率。通过氟和氢核磁共振波谱 (19F 和 1H NMR) 评估合成产物的微观结构。发现 C2 对与 VDF（以及 VDF/VAc）的共聚具有抑制/延迟作用。然而，通过尽可能减少 VAc 在水相中的均相成核，合成了含有 VAc 和 VDF 的统计共聚物。这是通过在 VDF 的均相凝聚成核（引发剂注入后约 5 分钟）发生后将 VAc 加入反应中来实现的。
