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Processing properties of polypropylene with a minor addition of silicone oil
Author(s) -
Zhang Wei,
Deodhar Sarang,
Yao Donggang
Publication year - 2010
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.21665
Subject(s) - rheometry , materials science , composite material , silicone oil , rheology , lubricant , die swell , shear rate , polypropylene , silicone , polybutene , extrusion , viscosity , polymer
Processing‐related properties of a polypropylene (PP)/silicone oil blend were investigated. It was found that an addition of a small amount (∼2 wt%) of silicone oil, a low molecular weight linear poly(dimethyl siloxane) (PDMS), drastically changed the rheological properties of PP. The PDMS seemed to work both as an internal lubricant and an external lubricant in the blend system. In particular, the apparent viscosity of the blend in capillary rheometry was approximately 10 times lower than that of virgin PP. The local minima in the viscosity versus shear rate curve in capillary rheometry and the gap‐dependency of viscosity in parallel‐plate rheometry implied the existence of a slip wall condition, caused by the formation of a thin lubricant layer at die walls. Thermal analyses and mechanical tests showed that the thermal and mechanical properties of the blend were nearly unaffected by the minor addition of silicone oil. The blend was tested in a profile extrusion process, and a significant reduction in die swell and profile distortion was achieved. The jet stretchability or spinnability in fiber spinning was also greatly improved with the minor addition of silicone oil. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers