MORPHOLOGY-PROPERTY RELATIONSHIP OF SEGMENTED POLYURETHANEUREA - INFLUENCES OF SOFT-SEGMENT STRUCTURE AND MOLECULAR-WEIGHT

The relationships of the morphology and properties of a series of segm ented polyurethaneurea (PUU) were studied in film form by using SEM an d tensile stress-strain data. The polyether-based and polyester-based PUU block copolymers were synthesized using poly (propylene oxide)-eth ylene oxide polyether or poly (butylene adipate) polyester with differ ent molecular weights, 4,4-methylene bis (phenyl isocyanate), and diet hyltoluene diamine. The extent of phase separation increased with incr easing molecular weight of the soft segment. The polyether-based PUU s howed better phase separation than did polyester-based PUU with the sa me molecular weight soft segment. The polyether-ester-based PUU showed the morphology of both polyether-based and polyester-based PUU but wi th larger domain size and interface.