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Enhancement of mechanical and optical performance of commercial polystyrenes by blending with siloxane‐based copolymers
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Mario Daniel Ninago Vivina Hanazumi María Gabriela Passaretti Daniel Alberto Vega Andrés Eduardo Ciolino Marcelo Armando Villar 《应用聚合物科学杂志》2017,134(30)
Well‐defined poly(styrene‐block ‐dimethylsiloxane) copolymers (PS‐b ‐PDMS) with low polydispersity index (Mw /Mn ) and different compositions were synthesized by sequential anionic polymerization of styrene (S) and hexamethyl(ciclotrisiloxane) (D3) monomers. Synthesized PS‐b ‐PDMS copolymers were characterized by 1H‐nuclear magnetic resonance, size exclusion chromatography, Fourier transform infrared spectroscopy, and transmission electron microscopy. The physicochemical characterization determined that block copolymers have molar mass values close to ~135,000 g mol?1, narrow Mw /Mn < 1.3, and chemical composition ranging from low to intermediate PDMS content. Blends of these copolymers with a commercial polystyrene (PS) were obtained by melt mixing and subsequently injection. Films obtained were flexible, and showed lower transparency than the original PS matrix. On the other hand, a 10 wt % incorporation of PS‐b ‐PDMS copolymers leads to better mechanical performance by enhancing elongation at break (~8.8 times higher) and opacity values (~18 times higher). In addition, UV–Vis barrier capacity of the resulting blends is also increased (up to 400% higher). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45122. 相似文献
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本文阐述了大面积机房的烟烙尽系统的设计和水力计算,以及大面积的机房安全性、有效性的技术措施。本文具体分析了问题产生的原因,并通过国家规范和相关标准论述了解决的方法。 相似文献
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