期刊文献+

二次检索

题名
关键词
文摘
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息

年份

学科

期刊

共找到2篇文章
< 1 >
每页显示 20 50 100
Study on Nitrogen Forms in Phenolic Polymers Incorporating Protein by ^(15)N CP-MAS NMR
1
作者 CHENGLILI WENQIXIAO 《Pedosphere》 SCIE CAS CSCD 1996年第2期97-106,共10页
Phenolic polymers synthesized by reactions of p-benzoquinone with 15N-labelled protein or(15NH4)2SO4 were studied by using 15N CP-MAS NMR technique in combination with chemical approaches.Results showed that more than... Phenolic polymers synthesized by reactions of p-benzoquinone with 15N-labelled protein or(15NH4)2SO4 were studied by using 15N CP-MAS NMR technique in combination with chemical approaches.Results showed that more than 80% of nitrogen in quinone-protein polymers was in the form of amide with some present as aromatic and/or aliphatic alone and less than 10% of nitrogen occurred as heterocyclic N.The nitrogen distribution in the non-hydrolyzable residue of the quinone-protein polymers was basically similar to that of soil humic acid reported in literature with the exception that a higher proportion of N as heterocyclic N and aromatic amine and a lower proportion of N as amide and aliphatic amine were found in the former than in the latter. More than 70% of total nitrogen in quinones(NH4)2SO4 polymer was acid resist ant,of which about 53% occurred as pyrrole,nitrile and imino type N.The possible roles of the reactions of phenols or quinones with proteins in the formation of humic acid,especially the non-hydrolyzable nitrogen in humic acid,are discussed. 展开更多
关键词 humic acid  ̄(15)N NMR phenolic polymer
下载PDF
Fluxing Agents on Ceramification of Composites of MgO-Al2O3-SiO2/Boron Phenolic Resin 被引量:5
2
作者 石敏先 CHEN Xia +3 位作者 FAN Shanshan SHEN Shirley LIU Tianxiang 黄志雄 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第2期381-388,共8页
Fluxing agents of zinc borate, antimony oxide, galss frit A and glass frit B, with different melting or softening point temperatures, were added into MgO-Al_2O_3-SiO_2/boron phenol formaldehyde resin(MAS/BPF) compos... Fluxing agents of zinc borate, antimony oxide, galss frit A and glass frit B, with different melting or softening point temperatures, were added into MgO-Al_2O_3-SiO_2/boron phenol formaldehyde resin(MAS/BPF) composites to lower the formation temperature of eutectic liquid phase and promote the ceramification of ceramifiable composites. The effects of fluxing agents on the thermogravimetric properties, phase evolution, and microstructure evolution of MAS/BPF composites were characterized by TG-DSC, XRD and SEM analyses. The results reveal that the addition of a fluxing agent highly reduces the decomposition rate of MAS/BPF composites. Fluxing agents lower the formation temperatures of liquid phases of ceramifiable MAS/BPF composites obviously, and then promote the ceramification and densification process. The final residues of composites are ceramic surrounded by large amount of glass phases. 展开更多
关键词 ceramification boron phenolic resin ceramifiable polymer composite fluxing agent
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部