کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10624547 | 989603 | 2015 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Preparation of finely macroporous SiOC foams with high mechanical properties and with hierarchical porosity via pyrolysis of a siloxane/epoxide composite
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Mechanically strong SiOC foams were prepared via pyrolysis of polysiloxane composites, into which 20-70 wt% of epoxy powder were incorporated as sacrificial filler. The chosen epoxy filler degrades practically quantitatively during the pyrolysis in nitrogen, due to a high content of polyoxypropylene chains. The pyrolysis of the composite precursors yielded SiOC foams with apparent densities between 1.31 and 0.62 g/cm3, which corresponded to macro-porosities of 35-69%. A hierarchical porosity was obtained due to a relatively wide distribution of the sacrificial filler grains׳ size. Compressive strength between 15 and 38 MPa was achieved, depending on the apparent density of the SiOC foams: the best result was obtained for the foam with 56% porosity. In the case of denser foams, their strength was reduced by the presence of pyrolysis cracks, while at 70% porosity, the thinner pore walls led to a reduced strength. The elastic modulus of the most promising foam (56% porosity) was found to be 10 GPa.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 41, Issue 7, August 2015, Pages 8402-8410
Journal: Ceramics International - Volume 41, Issue 7, August 2015, Pages 8402-8410
نویسندگان
Adam Strachota, Martin Äerný, ZdenÄk Chlup, Krzysztof RodzeÅ, Katarzyna Depa, Martina Halasová, Miroslav Å louf, Jana Schweigstillová,