کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5177601 1502476 2017 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Poly(methylhydrosiloxane) networks of different structure and content of Si-H groups: Physicochemical properties and transformation into silicon oxycarbide ceramics
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Poly(methylhydrosiloxane) networks of different structure and content of Si-H groups: Physicochemical properties and transformation into silicon oxycarbide ceramics
چکیده انگلیسی


- Polysiloxane networks of different structures were prepared by hydrosilylation.
- The obtained networks contained various amounts of Si-H groups.
- Amounts of Si-H groups and structure influence thermal decomposition of the systems.
- Pyrolysis of the obtained networks leads to SiCO materials and a free carbon phase.

In the work, poly(methylhydrosiloxane) was cross-linked by three vinylsiloxanes differing in molecular structure and functionality, i.e. linear difunctional ViMMVi, branched tetrafunctional Q(MVi)4 and cyclic tetrafunctional D4Vi. The cross-linking process was conducted at three molar ratios of Si-H to Si-CH=CH2 groups in order to obtain different amounts of unreacted Si-H groups in the systems. As established by swelling measurements, the applied cross-linker and molar ratio of reactive groups show the influence on the average cross-linking densities of the studied systems. Conducted thermal investigations allowed to conclude that the amount of Si-H groups present in the system affects the number of decomposition steps of the studied networks. The results of thermal studies of the cross-linked samples were complemented by FTIR and XRD analyses of the residues formed after pyrolysis of the cross-linked products conducted at different temperatures in the range between 200 and 1000 °C in Ar atmosphere. The presence of the free carbon phase in the obtained silicon oxycarbide materials was confirmed by Raman spectroscopy.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 130, 9 November 2017, Pages 170-181
نویسندگان
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