接枝共聚法制备聚乙二醇(PEG)/聚乙烯醇(PVA)高分子固-固相变材料性能研究

用接枝共聚法将具有相变特征的聚乙二醇(PEG)接枝到具有较高熔点的聚乙烯醇(PVA)主链上,得到了系列性能稳定的PEG/PVA高分子固-固相转变材料,用DSC,WAXD和POM对其相变行为及形态结构进行了研究.结果表明,该材料呈现出可逆的固-固相转变特性;其结晶峰值温度和相变焓比纯PEG低,接枝率对相变温度和归一化相变焓影响不大;接枝率只影响结晶与熔融行为,不影响结晶结构.

Preparation and Properties of Polymeric Solid-solid Phase Change Materials of Polyethylene Glycol(PEG)/Poly(vinyl alcohol)(PVA) Copolymers by Graft Copolymerization

New serials of PVA-g-PEG graft copolymers with different molecular weights and different graft ratios were prepared. In these new materials,the rigid polymer PVA served as a skeleton, and the flexible polymer PEG served as a functional branch chain. The structures of the copolymers were measured with FTIR. Their phase change properties and crystallization behavior were analyzed by DSC, POM, and WAXD. During the transition, the whole polymers remained in the solid state, they all had solid-solid phase transition properties, and the phase transitions were all reversible. Compared with pure PEG, the maximum crystalline temperatures and enthalpies of the graft copolymers declined because of the addition of PVA and the value of phase change temperatures and enthalpies had no relationship with their graft ratio. The crystalline degrees of these phase change materials were affected due to the intermolecular interaction and chemical bond.