Thermal and mechanical properties of solution polymerized segmented polyurethanes with butadiene soft segments

摘要: Abstract A series of HTPBD containing polyurethanes high molecular weight have been synthesized in solution. The value the soft segment Tg is very close to that free and independent hard content indicating complete or nearly phase segregation. Since segments TDI/BDO are amorphous, driving force for segregation must arise from large degree incompatibility between polar nonpolar segment. Furthermore, these samples there also no opportunity hydrogen bonding enhance compatibility. values glass transition increase with average length following a Fox-Flory type relationship. In contrast observed bulk polymerized samples, only single occurred present study. This indicates double behaviour result heterogeneous nature polymerization. With increasing content, properties vary rigid elastomers, rubber roughened plastics. variation caused by changes sample morphology which depends upon relative fractions segments. Mechanical show marked improvement over corresponding samples. Unlike polyester polyether urethanes, materials evidence change thermal treatment effect history on mechanical properties.