Isophorone diisocyanate(IPDI), polycarbonate diol(PCD), dimethylol propionic acid(DMPA)를 출발물질로 하여 제조된 폴리우레탄 prepolymer의 미반응 NCO기를 아크릴 단량체인 pentaerythritol triacrylate(PETA)로 capping시켜 acrylic terminated polyurethane prepolymer를 합성하였다. 그 후 이 prepolymer의 잔여 NCO기를 실란커플링제인 aminopropyl triethoxysilane(APS) 또는 glycidoxypropyl trimethoxysilane(GPTMS)와 반응시켜 silylated acrylic terminated waterborne polyurethane을 제조하였다. 동적 빛 산란법에 의해 측정된 순수한 수분산 폴리우레탄의 평균 직경은 PETA와 APS가 첨가됨에 따라 14.3 nm에서 208.6 nm로 크게 증가하였다. 또한 silylated acrylic terminated waterborne polyurethane 코팅 도막의 연필경도 및 내마모성은 순수한 수분산 폴리우레탄보다 우수하였다.
Acrylic terminated polyurethane prepolymers were synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA), with pentaerythritol triacrylate (PETA). Subsequently, silylated acrylic terminated prepolymers were prepared by capping the NCO groups of acrylic terminated polyurethane prepolymers with different types of silane coupling agents, glycidoxypropyl trimethoxysilane (GPTMS) or aminopropyl triethoxysilane (APS). The average particle size of pure waterborne polyurethane solution, measured by the dynamic light scattering method, was increased from 14.3 nm to 208.6 nm by adding PETA and APS. Also, the coating film of silylated acrylic terminated waterborne polyurethane showed better abrasion resistance and pencil hardness than that of pure waterborne polyurethane.
