A latent curing agent for rapid curing of phenolic epoxy resin at low temperature

IF 2.8 3区化学 Q2 POLYMER SCIENCE

Journal of Applied Polymer Science Pub Date : 2024-07-16 DOI:10.1002/app.56003

Jian-Qiao Guo, Xing-Hong Zhang

{"title":"A latent curing agent for rapid curing of phenolic epoxy resin at low temperature","authors":"Jian-Qiao Guo, Xing-Hong Zhang","doi":"10.1002/app.56003","DOIUrl":null,"url":null,"abstract":"<p>Developing effective latent curing agent for rapid curing of epoxy resins at low temperatures remains challenging. This study reports a latent curing agent, ortho-cresol phenolic epoxy resin-bisphenol A (EOCN-BPA), prepared through the addition reaction of o-methyl phenolic epoxy resin with BPA. When blended with dicyandiamide (DICY) in a 1:3 molar ratio, EOCN-BPA/DICY is used to cure a linear epoxy phenolic novolac (EPN) resin (epoxy equivalent: 550 g eq<sup>−1</sup>, softening point: approximately 82°C), at an onset curing temperature of 90°C, which is considerably lower than the onset curing temperature of DICY with EPN (160°C). However, EOCN-BPA does not react with EPN without a catalyst. Therefore, this latent curing system is successfully applied in powder coatings, rapid curing at 120°C within 3 min without an additional catalyst, outperforming the EPN/EOCN-BPA system using cocatalyst 2-methylimidazole. Consequently, DICY catalyzes the curing reaction between the phenol hydroxyl group and epoxy resin and participates in it. The prepared powder coating exhibits excellent storage stability, maintaining its properties for over 3 months at room temperature. These findings demonstrate the excellent latent properties of EOCN-BPA/DICY, highlighting its potential as a highly effective latent curing agent.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 39","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Polymer Science","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/app.56003","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}

引用次数: 0

Abstract

Developing effective latent curing agent for rapid curing of epoxy resins at low temperatures remains challenging. This study reports a latent curing agent, ortho-cresol phenolic epoxy resin-bisphenol A (EOCN-BPA), prepared through the addition reaction of o-methyl phenolic epoxy resin with BPA. When blended with dicyandiamide (DICY) in a 1:3 molar ratio, EOCN-BPA/DICY is used to cure a linear epoxy phenolic novolac (EPN) resin (epoxy equivalent: 550 g eq⁻¹, softening point: approximately 82°C), at an onset curing temperature of 90°C, which is considerably lower than the onset curing temperature of DICY with EPN (160°C). However, EOCN-BPA does not react with EPN without a catalyst. Therefore, this latent curing system is successfully applied in powder coatings, rapid curing at 120°C within 3 min without an additional catalyst, outperforming the EPN/EOCN-BPA system using cocatalyst 2-methylimidazole. Consequently, DICY catalyzes the curing reaction between the phenol hydroxyl group and epoxy resin and participates in it. The prepared powder coating exhibits excellent storage stability, maintaining its properties for over 3 months at room temperature. These findings demonstrate the excellent latent properties of EOCN-BPA/DICY, highlighting its potential as a highly effective latent curing agent.

Abstract Image

查看原文本刊更多论文

一种在低温下快速固化酚醛环氧树脂的潜伏固化剂

开发在低温下快速固化环氧树脂的有效潜固化剂仍具有挑战性。本研究报告介绍了一种潜伏固化剂--邻甲酚酚醛环氧树脂-双酚 A（EOCN-BPA），它是通过邻甲基酚醛环氧树脂与双酚 A 的加成反应制备而成的。当以 1:3 的摩尔比与双氰胺（DICY）混合时，EOCN-BPA/DICY 可用于固化线性环氧酚醛酚醛树脂（EPN）（环氧当量：550 克当量-1，软化点：约 82°C），固化起始温度为 90°C，大大低于双氰胺与 EPN 的固化起始温度（160°C）。然而，在没有催化剂的情况下，EOCN-BPA 不会与 EPN 发生反应。因此，这种潜伏固化体系成功地应用于粉末涂料，在 3 分钟内达到 120°C 的快速固化温度，而无需额外的催化剂，其性能优于使用 2-甲基咪唑作助催化剂的 EPN/EOCN-BPA 体系。因此，DICY 催化并参与了苯酚羟基与环氧树脂之间的固化反应。制备的粉末涂料具有极佳的储存稳定性，在室温下可保持 3 个月以上。这些研究结果证明了 EOCN-BPA/DICY 的优异潜伏特性，凸显了其作为高效潜伏固化剂的潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Applied Polymer Science 化学-高分子科学

CiteScore

5.70

自引率

10.00%

发文量

1280

审稿时长

2.7 months

期刊介绍： The Journal of Applied Polymer Science is the largest peer-reviewed publication in polymers, #3 by total citations, and features results with real-world impact on membranes, polysaccharides, and much more.