聚氨酯-环氧树脂-松香复合乳液的合成与表征

以聚已内酯二醇、甲苯二异氰酸酯、二羟甲基丙酸为基料, 以三羟甲基丙烷为交联剂，采用环氧树脂和松香对水性聚氨酯进行改姓，制备出环氧树脂和松香改性的聚氨酯复合乳液。用傅立叶变换红外光谱、粒度分析仪、凝胶渗透色谱、综合热分析仪等对其进行了表征。红外分析表明，环氧树脂中的羟基与异氰酯基发生反应，生成了氨基甲酸酯基,同时环氧基进行了开环反应，接枝到聚氨酯分子上；松香中羧基也参与了体系的反应，最终形成了环氧和松香改性水性聚氨酯。环氧树脂和松香含量增大，都会导致乳液粒径增大。改性后聚氨酯复合乳液的相对分子质量有一定程度的增大，达7.43Х105g.mol-1。三羟甲基丙烷用量对剥离强度有显著影响，其用量以不超过2.7%为宜。改性后聚氨酯的相容性好， 其胶膜分解温度高达260℃。采用该乳液制成的胶粘剂对多种复合薄膜具有较强的粘接能力。

Synthesis and Characterization of Polyurethane-Epoxy Resin-Rosin Hybrid Emulsion

Waterborne polyurethane (WPU)　hybrid emulsions were prepared from polycaprolactone glycol(PCL), tolylene diisocyanate (TDI), dimethylolpropionic acid (DMPA), with trimethylol- propane (TMP) as a cross-linker, the epoxy resin and rosin as modification agents. The structure and properties of hybrid emulsions were characterized by Fourier Transform Infrared (FTIR), Particle Size Analyzer，Gel Permeation Chromatography (GPC)，and Differential Scanning calorimetry(DSC). The spectrum of FTIR showed that the epoxy resin was grafted onto the PU molecule, and rosin reacted. The average particle size of WPU hybrid emulsions increased when the contents of epoxy resin and rosin increased. The molecule weight (Mn) of the modified WPU was up to 7.43Х105 g.mol-1. The content of TMP severely affected on the WPU film’s T-peel strength and its optimum content was near and no more than 2.7%. The spectrum of DSC showed the epoxy resin, PU and rosin had good compatibility. The cast films of the modified WPU possessed the high thermal stability, and their decomposition temperature was above 260℃.The adhesive formulated by the modified waterborne polyurethane emulsion could be used for adhesion of laminated package films with strong adhesion strength.