Study on Preparation and Mechanical Properties of Polyamide 6-polyurethane Block Copolymers

In order to improve impact toughness of monomer casting polyamide 6,polyamide 6-polyurethane(PA6-PU) block copolymers are prepared by monomer casting process.Differential scanning calorimetry(DSC),dynamic mechanical analysis(DMTA) and mechanical properties test are conducted to study influence of the content of PU soft component upon structure and properties of PA 6-PU block copolymers.The results show that there are two melting peaks at 15%～20% content of PU propolymer,which suggests the size distribution of crystal nucleus is wide.Single glass temperature of the copolymers is confirmed by DMTA illuminated the presence of a single phase in copolymers.The results of mechanical properties of the copolymers show that with the increases of PU content tensile strength of the copolymers decreases,the impact strength of the copolymers can be significantly improved at-50℃ and 25℃.