摘要
以双酚A环氧树脂(E-12)为基体,4,4'-二氨基二苯砜(DDS)为固化剂,2-甲基咪唑(2-MI)为促进剂,经熔融共混制成的环氧粉状胶黏剂为研究对象,采用差示扫描量热分析(DSC)、热重分析(TGA)及力学性能测试分析了2-MI用量对E-12/DDS/2-MI体系的力学性能及固化性能的影响。结果表明:与E-12/DDS体系相比,加入2-MI在E-12/DDS体系中可以改善韧性。当2-MI含量为0.2%质量分数时,E-12/DDS/2-MI体系的力学性能最佳,其冲击强度和拉伸强度分别为11.2 k J/m^2和43.54 MPa,分别较E-12/DDS体系提高了28.7%和21.3%;与E-12/DDS体系相比,加入2-MI使起始分解温度降低,从而使E-12/DDS/2-MI体系的热稳定性有所降低; 2-MI的添加降低了E-12/DDS/2-MI体系的表观活化能,有助于降低固化温度和缩短固化时间。研究表明,E-12/DDS/2-MI体系的固化条件为:从93.43℃开始体系发生固化反应,在127.5℃时体系达到充分固化,至172.87℃下体系固化完全。E-12/DDS/2-MI体系的最佳固化工艺为130℃/12 min。
As a kind of novel epoxy resins without any solvent,powder epoxy adhesives have recently received considerable attention because of the imposition of increased legislative restrictions on the emission of organic solvents to the atmosphere. Because of these attractive properties as well as advantages of non-toxicity,ease of use,and high recycling rate,the powder epoxy adhesive can be applied for the industrial application. However,application areas of powder epoxy adhesives were limited due to the drawbacks of poor mechanical properties and high curing temperature.In order to extend the application range of powder epoxy adhesive from heat-resistant substrates( such as metals) to heat-sensitive substrates( such as plastic products,cardboard and wood),it is necessary to decrease the curing temperature.In this study,a series of powder epoxy adhesives were prepared by meltblending method with Bisphenol A epoxy resins( E-12) as the matrix,4,4’-Diaminodiphenyl sulfone( DDS) as a curing agent,and 2-methylimidazole( 2-MI) as an accelerant. The effect of the 2-methylimidazole content on mechanical,thermal and curing properties of E-12/DDS/2-MI systems were studied. Compared with the E-12/DDS system,the optimal overall performance was obtained when the E-12/DDS/2-MI systems contained 0.2 wt% 2-MI. The impact strength and tensile strength of E-12/DDS/2-MI systems reached 11.2 MPa and 43.54 MPa,which were 28.7% increase in impact strength and 21.3%increase in tensile strength,respectively. The TGA results showed that E-12/DDS/2-MI systems had a lower thermal stability in comparison with the E-12/DDS system. The DSC results revealed that the incorporation of 2-MI into the E-12/DDS/2-MI system could decrease the curing temperature. The incorporation of 2-MI also could lower the activation energy,contributing to reduction of the curing temperature and shortening the curing time. Based on Kissinger,Ozawa and Crane kinetic analyses,the action energy and the order of curing reaction were obtained by kinetics calculation to be 64.
作者
徐杰
王恒旭
张金杰
白栋
杨佳瑶
刘晓欢
傅深渊
XU Jie;WANG Hengxu;ZHANG Jinjie;BAI Dong;YANG Jiayao;LIU Xiaohuan;FU Shenyuan(Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-efficiency Utilization,Key Laboratory of Wood Science&Technology of Zhejiang Province,School of Engineering,Zhejiang A&F University,Hangzhou 311300,China)
出处
《林业工程学报》
CSCD
北大核心
2019年第2期66-72,共7页
Journal of Forestry Engineering
基金
浙江省自然科学基金重点项目(LZ16C160001)
国家科技支撑计划项目(2015BAD14B0305)
国家重点研发计划项目(2017YFD0601105)
