effect of castor oil content on viscosity of castor tdi prepolymers

Castor oil is a renewable oil that can be used for making polyurethane products. tdi and castor oil prepolymers can be used to make copolymers with desirable properties. different ratios of castor oil and tdi mixed (based on stoichiometric calculations) to make prepolymers. next, using a fordcup viscometer, the kinematic viscosity of products are measured. moreover, the viscosity decrease with increased nco content which leads to a reduction in hydrogen bonds and urethane groups. the kinematic viscosity and nco: oh ratio shows a linear trend on a logarithmic scale.