Novel Sulfur‐Containing Cross‐Linking Agent for Si‐Based Preceramic Polymers
Novel Sulfur‐Containing Cross‐Linking Agent for Si‐Based Preceramic Polymers
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新型含硫硅基陶瓷预聚物交联剂
DOI：
10.1002/macp.201900380
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发表时间：
2019
影响因子：
2.5
通讯作者：
Kroll, Peter
中科院分区：
文献类型：
--
作者：
Taheri, Poroshat;Bokka, Apparao;Asgari, Parham;Jeon, Junha;Lang, John C.;Campostrini, Renzo;Sorarù, Gian Domenico;Kroll, Peter
聚甲基氢硅氧烷（PMHS）与二乙烯基噻吩（DVT）在高度稀释的条件下通过硅氢化交联，随后在co2中进行超临界干燥，得到含有芳香硫的聚合物气凝胶，完整且均匀地分布在整个单体中。傅里叶红外（FT - IR）光谱分析表明，产品中的乙烯基和Si - H键几乎完全消耗。FT - IR和拉曼光谱分析都支持乙烯基与噻吩环保留的双键的共轭损失。扫描电子显微镜（SEM）显示出凝聚态胶体结构，特征颗粒直径约为165 nm。SEM和能量色散X射线能谱元素图表明，硫在聚合物气凝胶中分布均匀。介孔气凝胶的孔隙度测定表明，其有效平均孔径约为12 nm。热重分析（TGA）表明PMHS - DVT产物比任何一种纯未反应组分具有更高的热稳定性。热重分析（TGA）和质谱（TG - MS）对热解过程中释放的挥发物的鉴定表明，硫是由交联聚合物作为噻吩及其衍生物驱动的。记录的质谱支持聚合物气凝胶中PMHS链之间交联DVT桥的假设，这导致了更热稳定的整体。
Cross‐linking polymethylhydrosiloxane (PMHS) with divinylthiophene (DVT) via hydrosilylation in highly dilute conditions and subsequent supercritical drying in CO2yield a polymeric aerogel containing aromatic sulfur integrally and uniformly distributed throughout the monolith. Fourier‐transform infrared (FT‐IR) spectroscopy indicates almost complete consumption of vinyl groups and SiH bonds in the product. Both FT‐IR and Raman spectroscopic analyses support loss of conjugation of vinyl groups with the retained double bonds of the thiophene ring. Scanning electron microscopy (SEM) indicates a condensed colloidal structure with characteristic particulate diameters of about 165 nm. SEM coupled with energy dispersive X‐ray spectroscopy elemental mapping shows that sulfur is distributed homogeneously in the polymeric aerogel. Porosimetry of the mesoporous aerogel indicates the effective average pore diameters are about 12 nm. Thermogravimetric analysis (TGA) establishes greater thermal stability of the PMHS‐DVT product than either of the pure unreacted components. TGA coupled with mass spectrometric (TG‐MS) identification of the volatiles released during pyrolysis shows that sulfur is driven from the cross‐linked polymer as thiophene and its derivatives. Recorded mass spectra support the hypothesis that cross‐linking DVT bridges between PMHS chains in the polymeric aerogel, and that this results in a more thermally stable monolith.
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影响因子：
2.5
作者：
S. Zhai;Li Zhang;B. Zhai;Qing-da An
通讯作者：
S. Zhai;Li Zhang;B. Zhai;Qing-da An
当硅基聚合物转变为陶瓷相时断裂开始
影响因子：
3.9
作者：
Raj, Rishi;Pederiva, Luca;Narisawa, Masaki;Soraru, Gian Domenico
通讯作者：
Soraru, Gian Domenico
影响因子：
3.9
作者：
Colombo, Paolo;Mera, Gabriela;Soraru, Gian Domenico
通讯作者：
Soraru, Gian Domenico
影响因子：
3.4
作者：
Aguirre-Medel, Susana;Jana, Prasanta;Soraru, Gian Domenico
通讯作者：
Soraru, Gian Domenico
影响因子：
--
作者：
Campostrini, R;DAndrea, G;Soraru, GD
通讯作者：
Soraru, GD