Promoting effect of methyne/methylene moiety of bisphenol E/F on phthalonitrile resin curing: Expanding the structural design route of phthalonitrile resin

• Published in: Polymer (Guilford) Vol. 210; p. 123001
• Main Authors: Liao, Shenjun, Wu, Hao, He, Xian, Hu, Jiang-huai, Li, Renke, Liu, Yao, Lv, Jiangbo, Liu, Yang, Liu, Zhengzhou, Zeng, Ke, Yang, Gang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2020; Elsevier BV
• Subjects: Benzene; Bisphenol A; Curing; Curing mechanism; Dynamic mechanical analysis; Free radicals; Gravimetric analysis; Methylene; Methyne; Monomers; Phthalonitrile; Promoting effect; Resins; Rheological properties; Rheology; Structural design; Structural engineering; Thermal analysis; Thermal properties; Thermodynamic properties; Promoting effect; Phthalonitrile; Methyne; Curing mechanism; Methylene
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2020.123001

In this paper, three phthalonitrile (PN) model compounds containing benzene ring-linked alkyl units, bisphenol A (methyl) phthalonitrile monomer (BPAh), bisphenol E (methyne) phthalonitrile monomer (BPEh) and bisphenol F (methylene) phthalonitrile monomer (BPFh), were synthesized. It was confirmed that methylene/methyne could effectively promote the curing reaction of phthalonitrile. Rheology analysis showed that the promotion effect of methylene is stronger than that of methyne, but methyl has no obvious promotion effect. The effect of DPPH on the reaction rate, added considerable evidences that the curing reaction of BPEh and BPFh involved a free radical process. Qualified thermal properties were investigated by Dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA). For post-cured resin of BPEh and BPFh, the Tg is more than 500 °C, the T5% were observed at 495 °C and 491 °C, and the char yield in 800 °C reached 73.1% and 71.9% respectively. [Display omitted] •Three PN model compounds with benzene ring-linked alkyl units were designed and synthesized.•Methylene and methyne could effectively promote the reaction of phthalonitrile.•The effect of DPPH indicated that curing reaction of BPEh and BPFh involved a free radical process.