HDI-IPDI型高固含量水性聚氨酯分散体的合成及微观形态

以预聚体分散法合成了固含量达50%的高固含量水性聚氨酯分散体.研究了影响高固含量水性聚氨酯分散体的黏度、粒径、粒径分布及粒子微观形态的因素.结果表明,随着DMPA含量、HDI/IPDI摩尔比及软段分子量(M)n的增加,乳液的黏度增大,粒径减小.粒径分布随着DMPA含量及PBA分子量的增加而变窄,HDI/IPDI对粒径分布的影响较小;在DMPA含量较低或者PBA分子量在2000以下时获得的分散体具有较广的粒径分布.此外,分散液还呈现出二元粒径分布趋势.透射电镜对胶束形态研究表明,随着软段分子量的增加,胶束呈现出聚集趋势,并且随着DMPA含量的增加,聚集更紧密.

Synthesis of HDI-IPDI Based High Solid Content Aqueous Polyurethane Dispersion and Study on the Micromorphology of the Dispersion

Aqueous polyurethane(APU) dispersion having a solid content of 50% was synthesized using the pre-polymer process.The factors on viscosity,particle size,particle distribution and particle morphology of APU dispersion were determined.The results show that viscosity of the APU dispersion increases with increasing DMPA content,HDI/IPDI molar ratio and n of PBA,but the particle size decreases.Particle size distributions become narrower with increasing DMPA content or n of PBA,but are not significantly affected by HDI/IPDI moral ratio,very board particle size distributions were obtained at low DMPA content or small n value,in addition,bimodal were also observed from these high solid content APU.TEM photographs show that with increasing n of PBA,the APU particles exhibit a conglomeration trend and are aggravated by increasing DMPA content.