有机硅/丙烯酸酯改性水性聚氨酯的合成及性能

以异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)、聚酯二元醇(XH-111)、丙烯酸羟乙酯(HEA)和3-氨丙基三乙氧基硅烷(KH-550)等为主要原料,分别制得HEA封端和HEA、KH-550共同封端的水性聚氨酯乳液,再加入丙烯酸酯单体进行自由基引发聚合,分别制备出丙烯酸酯改性和丙烯酸酯、KH-550共同改性的水性聚氨酯复合乳液。通过傅立叶变换红外光谱(FTIR)、热失重分析(TGA)、X射线衍射分析(XRD)和力学性能测试,对改性水性聚氨酯乳液的结构和胶膜的热稳定性、结晶性和力学性能进行了考察。结果表明,改性水性聚氨酯的结晶性降低,热稳定性提高。当w(丙烯酸酯)增大到20%,w(KH-550)增大到15%时,胶膜的拉伸强度由5.6 MPa增加到23.9 MPa,断裂伸长率由491%降到247%。

Synthesis and Properties of Waterborne Polyurethane Modified by Organic Silicon and Acrylic Ester

Waterborne polyurethane emulsions were synthesized with isophorone diisocyanate(IPDI),dihydromethyl propionic acid(DMPA) and polyester glycol(XH-111),and then reacted with hydroxyethyl acrylate(HEA) or the mixture which included hydroxyethyl acrylate(HEA) and 3-aminopropyltriethoxylsilane(KH-550) to cap the terminal —NCO groups.These polyurethane emulsions were used to copolymerize with acrylates to synthesize the modified waterborne polyurethane composite emulsions through the free-radical emulsion polymerization.The structure,thermal stability and crystallinity of modified polyurethane were investigated by FTIR,TGA,XRD.The mechanical properties of the modified polyurethane films was also investigated.The results show that the crystallization of the modified waterborne polyurethane decreases and the thermal stability is improved.When the mass fraction of acrylate and KH-550 increased up to 20% and 15% respectively,the tensile strength of the modified polyurethane films increased from 5.6 MPa to 23.9 MPa and the elongation at break decreased from 491% to 247%.