聚氨酯丙烯酸酯的软/硬段比对紫外光固化胶粘剂性能的影响

Effect of soft/hard segment ratio of polyurethane acrylate on properties of UV-curing adhesive

以聚四氢呋喃醚二醇(PTMG)、六亚甲基二异氰酸酯(HDI)和羟丙基甲基丙烯酸酯(HPMA)为原料,调节加料比例,合成了一系列具有不同软/硬段比的可紫外光固化聚氨酯丙烯酸酯预聚物(编号为PMHH)。利用红外光谱仪(FT-IR)监测合成反应过程,并获得目标预聚物的红外光谱图;以预聚物PMHH为基础树脂,配制了一系列紫外光固化胶粘剂,利用FT-IR实时考察胶液的光聚合行为;探索了预聚物不同软/硬段比对胶液黏度以及光固化后样品的机械性能、热力学性能和固化收缩率的影响。研究结果表明:PMHH具有优异的柔韧性和低玻璃化转变温度(Tg),增加PMHH结构中软段的比例有利于紫外光固化胶柔韧性的提高,增加热稳定性,降低固化收缩。

A series of UV-curable polyurethane acrylate prepolymers(identified as PMHH)with different soft/hard segment ratios were synthesized by incorporating different ratios of polytetramethylene glycol(PTMG),hexamethylenediisocyanate(HDI)and hydroxypropyl methacrylate(HPMA).The synthesis process was monitored by Fourier transform infrared spectrometer(FT-IR),and the infrared spectrum of the target prepolymer was obtained.A series of UV-curing adhesives were prepared based on the prepolymer PMHH,and the photopolymerization behavior of the solution was investigated by real-time FT-IR.The effects of different soft/hard segment ratios of prepolymer on viscosity of adhesive solution and mechanical,thermodynamic properties and curing shrinkage of the sample after light curing were investigated.The research results showed that PMHH had excellent flexibility and low glass transition temperature(Tg).Increasing the proportion of soft segments in PMHH was conducive to the improvement of flexibility of UV-curing adhesive,which increased the thermal stability and reduced curing shrinkage.