Abstract
Prepolymer hydroxyl-terminated polybutadiene (HTPB) were NCO end-capped by reacting with excess toluene diisocyanate (TDI) and used as cocatalyst to initiate the anionic polymerization of epsilon -caprolactam. A series of poly( epsilon - caprolactam-b-butadiene) tri-block copolymer were prepared. The structural characterization included infra-red spectroscopy, element analysis, and gel permeation chromatograph analyses. Mechanical properties, such as yield strength, tensile modulus, flexural strength and modulus, elongation, heat distortion temperature and notched impact strength, were evaluated with respect to the content and molecular weight of polybutadiene in the tri-block copolymer. Morphology studies and thermal analysis revealed that phase separation occurred while the polybutadiene phase was the dispersed phase.