Flexible Epoxy Resins Formed by Blending with the Diblock Copolymer PEO-b-PCL and Using a Hydrogen-Bonding Benzoxazine as the Curing Agent

Polymers

Chih-Feng Huang¹  Lizong Dai²  Shiao-Wei Kuo³  Wei-Chen Su³  Fang-Chang Tsai⁴ 

[1] Department of Chemical Engineering, National Chung Hsing University, 145 Xingda Road, Taichung 402-27, Taiwan;Department of Material Science and Engineering, Fujian Provincial Key Laboratory of Fire Retardant Materials, College of Materials, Xiamen University, Xiamen, Fujian 361005, China;Department of Materials and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung 804, Taiwan;Hubei Key Laboratory of Polymer Materials, Key Laboratory for the Green Preparation and Application of Functional Materials (Ministry of Education), Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, School of Materials Science and Engineering, Hubei University, Wuhan 430062, China;

关键词: hydrogen bonding;    epoxy;    benzoxazine;    block copolymer;    toughness;   

DOI  :  10.3390/polym11020201

来源: DOAJ

【 摘 要 】

In this study, we enhanced the toughness of epoxy resin by blending it with the diblock copolymer poly(ethylene oxide⁻b⁻ε-caprolactone) (PEO-b-PCL) with a benzoxazine monomer (PA-OH) as the thermal curing agent. After thermal curing, Fourier transform infrared spectroscopy revealed that intermolecular hydrogen bonding existed between the OH units of the epoxy⁻benzoxazine copolymer and the C⁻O⁻C (C=O) units of the PEO (PCL) segment. Differential scanning calorimetry and dynamic mechanical analysis revealed that the glass transition temperature and storage modulus of the epoxy⁻benzoxazine matrix decreased significantly upon increasing the concentration of PEO-b-PCL. The Kwei equation predicted a positive value of q, consistent with intermolecular hydrogen bonding in this epoxy⁻benzoxazine/PEO-b-PCL blend system. Scanning electron microscopy revealed a wormlike structure with a high aspect ratio for PEO-b-PCL as the dispersed phase in the epoxy⁻benzoxazine matrix; this structure was responsible for the improved toughness.

【 授权许可】

Unknown