基于聚碳酸酯二元醇的高固含量聚氨酯分散体的合成与表征

以聚碳酸酯二元醇(PCDL)结合聚四氢呋喃(PTMG)为软段,以异佛尔酮二异氰酸酯(IPDI)为硬段,以N-(2-氨乙基)-2-氨基乙烷磺酸钠(AAS)为亲水单体,采用丙酮法制备了固含量在50％以上的高性能、高固含量聚氨酯分散体( PUDs).结果表明,随着亲水基团含量(HGC)的增加,PUD胶粒平均粒径变小,黏度增加；随着n(PCDL)∶n(PTMG)的减小和n(-NCO)∶n(-OH)(R值)的增加,PUD胶粒平均粒径变大,黏度减小.粒径分布随着亲水基团含量的增加而变窄,随着n(PCDL)∶n(PTMG)的减小和R值的增加而变宽.TEM显示在亲水基团较多时,聚氨酯分散体胶粒呈规则的球形结构,随着亲水基团含量的增加,胶粒的尺寸减小,且形状不规则的胶粒逐渐减少.力学性能测试显示PUD胶膜具有优良的机械性能,拉伸强度高达40 MPa,断裂伸长率可达1 700％.动态力学分析表征显示,PUD胶膜的玻璃化转变温度(Tg)随着PCDL含量减少而降低.

Synthesis and Characterization of High Solid Content Polycarbonate Diols Based Polyurethane Dispersions

The title high-performance and high solid content(>50%) PUD was synthesized by the acetone process,using polycarbonate diol(PCDL) and poly tetrahydrofuran(PTMG) as soft segments and isophorone diisocyanate(IPDI) as hard segment,and ethylenediamine sodium sulphonate(AAS-Na) as hydrophilic chain extender.The results showed that the particle size decreased and the viscosity increased with the increasing of hydrophilic group content(HGC),but the particle size increased and the viscosity decreased with the decreasing of PCDL content and the increasing of NCO/OH.Particle size distributions became narrower with increasing of HGC,but became wider with decreasing of PCDL content and increasing of NCO/OH.TEM showed that PUD particles were inerratic sphericity with more hydrophile,the particles became larger and the anomaly particles increased with decreasing of HGC.The results of tensile tests showed that PUD films had excellent mechanical properties,and the elongation at break of PUD free film was 1700% and the max elongation strength reached 40 MPa.Dynamic mechanical analysis showed that the glass transition temperatures(Tg) of PUD free films decreased with the decreasing of PCDL content.