无胺型水性聚氨酯-丙烯酸酯的制备及其热稳定性能研究

Study on Synthesis and Thermal Stability of Non-amine Waterborne Polyurethane-polyacrylate

摘要:

本文以耐高温型聚酯二元醇（NCL），4,4'-二环己基甲烷二异氰酸酯（HMDI），甲基丙烯酸甲酯（MMA）为主要原料，并同时采用羧酸型亲水扩链剂以及磺酸型亲水扩链剂，通过无有机溶剂法制备了满足烟盒包装行业要求的零挥发性有机物（VOC）、无三乙胺的耐高温型水性聚氨酯-丙烯酸酯（WPUA1～6）乳液。通过FTIR、TEM、粒径分析仪、TGA等考察了WPUA乳液及其胶膜的结构和性能。探讨了聚二元醇种类、异氰酸酯种类和扩链剂种类对胶膜热稳定性的影响。结果表明：加入乙二胺基乙磺酸钠(AAS)后乳液的平均粒径都减小。当热失重率分别为20%，30%，50%时，以耐高温NCL，HMDI和对苯二酚双(β-乙基)醚(HQEE)为原料合成的WPUA5胶膜热稳定性比以聚己内酯二元醇(PCL)，异佛尔酮二异氰酸酯（IPDI）和1,4-丁二醇（BDO）为原料合成的WPUA2胶膜热分解温度分别提高了60.96、69.37和139.70℃。随着WPUA5分子的对称性增强，聚合物的结晶性增强，玻璃化转变温度（Tg）也增大

Abstract:

Waterborne polyurethane polyacrylate emulsion (WPUA) was synthesized with thermotolerant polyester diol (NCL), 4,4’-dicyclohexyl methane diisocyanate(HMDI) and methyl methacrylate (MMA) as raw materials, using both carboxylic acid and sulfonate as hydrophilic chain extender agent. WPUA with zero VOC and no triethylamine was prepared by solvent-free method to meet the requirements of cigarette packaging industry. The WPUA emulsions and films were characterized by FT-IR, transmission electron microscope(TEM), partical size analysis and thermogravimetric analysis(TGA). The effects of different kinds of isocyanates, polyalcohol and chain extender on thermal stability of the WPUA films were investigated. The results showed that the average particle size of the emulsion was reduced due to the addition of aliphatic diamine sulphonate(AAS). TGA results showed that the decomposition temperature of WPUA5 film synthesized by NCL, HMDI and novel chain extender hydroquinone bis(β-ethyl) ether(HQEE) was higher than that of WPUA2 film synthesized by polycaprolactone diol(PCL), isophorone diisocyanate(IPDI) and 1,4-Butanediol(BDO), the decomposition temperature increased by 60.96℃, 69.37℃, 139.70℃ when the mass loss rate of WPUA film was 20%, 30%, 50%. And the crystallization and glass transition temperature (Tg) of polyurethane both increased with the enhancement of the symmetry of molecules.