酯基醇解桐油改性水性聚氨酯的研究.pdf

摘要摘要水性聚氨酯是以水代替有机溶剂作为分散介质的聚氨酯体系,与溶剂型聚氨酯相比,具有不含有机溶剂、不燃、操作方便、残胶易清理、气味小且无污染等许多优点。随着人们环保、健康意识的不断增强和环境法规的完善,溶剂型聚氨酯将逐渐被水性聚氨酯取代。随着石油资源的同益短缺,将具有可再生、生物降解和无毒特性的植物油分子引入聚氨酯中,不仅符合节约资源和绿色环保的要求,而且其产物有望兼具植物油和聚氨酯的综合优异性能及独特的链结构和相结构,成为一类新的环境友好型高分子材料。桐油是唯一一种带有三个共轭双键的植物油,桐油油膜具有附着力强、耐水、耐碱、耐同光大气等优点。将桐油引入到水性聚氨酯中, 有望得到综合性能优良的桐油基水性聚氨酯。本课题通过酯基醇解制备了羟基化桐油,并将羟基化桐油引入到聚氨酯分子中,制备出一系列的新型水性聚氨酯。利用红外光谱、质谱证实了桐油改性产物为预期产物,桐油基多元醇的羟值和碘值测定结果表明所得产物较完整地保留了桐油的共轭双键,达到了预期效果。从动态机械性能、红外光谱、粒径及Zeta电位等多个方面研究了硬段含量、桐油含量、桐油改性方法及加料方式对桐油基水性聚氨酯性能的影响。研究表明:硬段含量对乳液性能的影响主要是由DMPA含量的改变引起的,随着硬段含量增加,聚氨酯胶膜的储能模量增大,相分离趋于完全;改性桐油含量对水性聚氨酯性能的影响较为复杂,主要由其在聚氨酯中的位置和含量两方面决定,总的来说引入改性桐油可以增强软、硬段间的相容性,增大储能模量;同用氨解桐油改性的水性聚氨酯相比,醇解桐油改性的水性聚氨酯平均粒径较小,Zeta电位较高,体系较稳定,储能模量与损耗模量均较大,强度与耐冲击性较好,相分离较不完全;同两步法相比, 一步法制备的样品平均粒径较大,Zeta电位较低,氢键相互作用明显,储能模量与损耗模量均较大,强度和耐冲击性能较好,软、硬段分离完全。关键词:水性聚氨酯桐油酯基醇解动态力学性能 Abstract Abstract Waterbornepolyurethane(wvu)is abinarypolyurethane system which replaces solvents with water as a dispersion pared with solvent—based polyurethane,the WPU anic solvents,nonflammable,easy tooperate,easy toclean adhesive residue and no—harm the growing awareness of environmental protection andimprovement of environmental regulations,solvent-basedpolyurethane willgradually bereplaced byWPU. With thegrowing shortage ofoilresources,it is ofgreat significance ifplant oils which have the advantages of renewable,biodegradable and non—toxic can be incorporated intopolyurethane bine theexcellent properties from bothplant oil and polyurethane,because this is consistent with resource conservation and environmental protection plant oil-basedpolyurethane willbe a new class ofenvironment·friendly polymer materials with theunique chain andphase oilistheonlyplant oilwiththreeconjugated double bonds andhas many unique Tung oil-basedpolyurethane isexpected to have excellent overallperformance. In this research,Tung oilismodifiedby trimethylolpropane to make it hydroxylated through