Synthesis and properties of m-carborane-based bisphenol-type phenolic resin

• Published in: Hang kong cai liao xue bao Vol. 34; no. 1; pp. 46 - 51
• Main Authors: Qi, Shi-Cheng, Wang, Yao-Shuang, Wang, Hong-Rui, Zhang, Xiao-A, Jiang, Sheng-Ling, Lv, Ya-Fei
• Format: Journal Article
• Language: Chinese
• Published: 01.02.2014
• Subjects: Aeronautics; Catalysts; Formaldehyde; Gain; Nuclear magnetic resonance; Phenolic resins; Three dimensional; Transformations
• ISSN: 1005-5053
• DOI: 10.3969/j.issn.1005-5053.2014.1.008

1, 7-Bis(4-hydroxyphenyl)-m-carborane (preP1) was synthesized from m-carborane by Ullmann reaction, demethylation, and reaction with formaldehyde. The effects of catalyst species, phenol/formaldehyde molar ratio, temperature and time on synthetic reactions were carefully studied. The obtained preP1 was characterized with FTIR, (1)H NMR, (13)C NMR and MS methods. TGA behavior and structure transformation of cured preP1 was also investigated. The results show that preP1 (M(n)=1035) with hydroxymethylcarboranebisphenolA as main component was obtained when NaOH is used as catalyst under the condition of 100 degree C/8h. The char of cured preP1 at 900 degree C in nitrogen and air is 88.9% and 92.9%, which are much higher than that of commercially obtained boron-containing phenolic resin. It is believed that under air B-H bonds in preP1 could react with oxygen and transform to three-dimensional network structure containing B-O-B bonds. Therefore, the cured products gain weight at 685 degree C.