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Flame retardancy, thermal, rheological, and mechanical properties of polycarbonate/polysilsesquioxane system
Author(s) -
Wang Jiangbo,
Xin Zhong
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.31129
Subject(s) - polycarbonate , materials science , thermogravimetric analysis , differential scanning calorimetry , dynamic mechanical analysis , composite material , rheology , fire retardant , rheometry , char , polymer , glass transition , chemical engineering , thermodynamics , physics , pyrolysis , engineering
The polymethylphenylsilsesquioxane (PMPSQ) microspheres were used as an additive for the injection‐molding of polycarbonate (PC) in order to obtain a flame retardant polymer and to damage the other properties of PC as low as possible. The results showed that PMPSQ microspheres were a kind of effective flame retardant by the LOI test and the flame retardancy of PC increased with the increase of PMPSQ content. Thermogravimetric analysis suggested that the PMPSQ could induce crosslinking reactions and accelerate the thermal degradation of PC, sequentially promote the formation of the residue char during degradation. Differential scanning calorimetry measurement showed that the glass transition temperature of PC/PMPSQ system was decreased with the increase of PMPSQ content, which maybe caused by the enlarged free volume of PC‐rich phase. The rheological behaviors including dynamic and steady modes, combined with the analysis of scanning electron microscopy photographs, exhibited that the dispersion and compatibility of PMPSQ in the PC matrix decreased the viscosity of the systems and the addition of PMPSQ microspheres improved the processability of PC, but still there exist aggregation of PMPSQ microspheres in PC matrix, which gave a higher impact strength but a lower flexural modulus and elongation at break than pure PC. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010