硅烷改性水性聚氨酯表面施胶剂的制备与性能研究

Study on synthesis and properties of silicone-modified waterborne polyurethane sizing agent

以甲苯二异氰酸酯、混合多元醇为基本原料,N-甲基二乙醇胺为亲水扩链剂,有机硅为改性剂,通过醋酸中和反应制备出一种可用于纸张表面施胶的自乳化阳离子水性聚氨酯乳液;研究了硅烷用量、预聚温度、R值(体系中异氰酸酯基和羧基的摩尔比)、聚酯\聚醚质量比对乳液性能和施胶效果的影响。结果表明:硅烷用量为4.5%,预聚温度为60℃,R值为1.10,聚酯\聚醚质量比为3.6时制备的乳液性能良好;FT-IR分析表明有机硅烷已通过化学方法结合到聚氨酯分子链中;TGA分析表明有机硅的加入对水性聚氨酯耐热性有明显提高;粒径分析表明,有机硅的加入能使乳液粒子分布更均匀且粒径更小;施胶效果表明水性聚氨酯对改善纸张强度作用明显,有机硅烷的加入能显著提高纸张的施胶度。

Based on toluene diisocyanate（TDI）,polyether and polyester,used the N-methyl diethanolamine（MDEA） as chain extender,modified by organo-silicone,the waterborne polyurethane was synthesized by self-emulsion method which can be used as paper sizing agent.The influences of content of organo-silicone,the prepolymer reaction temperature,the NCO/OH mole ratio and the different quality ratio of polyether and polyester on the appearance and properties of emulsion were discussed.The results showed that when the content of organo-silicone was 4.5%,the prepolymer reaction temperature was 60℃,the NCO/OH mole ratio was 1.10 and the quality ratio of polyether and polyester was 3.6,the properties of emulsion was eminent.The Fourier transform infrared（FT-IR） spectrometer analysis showed that the blocking agent had already combined into the polyurethane molecular structure by chemical polymerization.The TGA analysis showed that the thermal property was improved evidently when the organo-silicone was added.The particle size analysis showed that the emulsion particle was smaller when the organo-silicone was added.The paper sizing experiment showed that the paper strength was enhanced evidently,the sizing degree was improved greatly when the organo-silicone was added.