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Influence of processing window and weight ratio on the morphology of the extruded and drawn PET/PP blends
Author(s) -
Li Wenjing,
Schlarb Alois K.,
Evstatiev Michael
Publication year - 2009
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21435
Subject(s) - materials science , polypropylene , polyethylene terephthalate , composite material , extrusion , die swell , maleic anhydride , phase inversion , ultimate tensile strength , composite number , polyethylene , phase (matter) , morphology (biology) , matrix (chemical analysis) , polymer , copolymer , chemistry , organic chemistry , membrane , biology , genetics
Abstract To obtain polyethylene terephthalate (PET)/polypropylene (PP) microfibrillar composite (MFC) with good mechanical properties, a high content of PET fibrils in the drawn strand (i.e. PET droplets in the extrudate) is preferred. However, a phase inversion (from PP matrix to PET matrix) takes place when the concentration of the PET reaches 40 wt% at the screw speed of 40 rpm (rounds per minute). This “PP domains in PET matrix” phase structure is the undesired phase structure for preparing MFC. However, the desired phase structure of “PET droplets in PP matrix” can be regained by adopting a low screw speed (20 rpm) during extrusion of the PET/PP (40/60); if a higher screw speed is adopted (80 rpm), then a suitable amount of PP grafted maleic anhydride (PP‐g‐MA) should be incorporated. The PET/PP blends which demonstrate the desired “PET droplets in PP matrix” phase structure were stretched into strands, and PET/PP MFC was prepared. The MFC with high content of PET microfibrils as the reinforcement exhibits superior tensile properties than the neat PP. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers