JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 31
·e52718
·
IF 3.057
Zhihang Ma,Xiao Wang,Junru Li,Xinlin Li,Chuanwei Zhang,Ruyi Zhang,Yan Gu,Pengfei Zhang
The reaction process and curing mechanism of self-healable epoxy resin TGDDM and curing agent TA are complicated. In this paper, the curing reaction kinetic mechanism of the system is studied from the perspective of isoconversional models. The n th-order model and autocatalysis model are established for observations of heat flow versus temperature and time during real-time curing obtained by non-isothermal differential scanning calorimetry (DSC), and evaluated under the standards of MSE, RMSE, and R -square. Under the guidance of least squares fitting, the pre-exponential factor ( A ), the activation energy ( E α ), the order of models ( n, m ) and other parameters in f α of the model are mainly estimated by Kissinger method, Ozawa method, Malek method, and other methods. The correlation between the activation energy ( E α ) of the reaction and the degree of conversion α also analyzed by the Flynn-Wall-Ozawa method. The chemical reaction of the system is studied by Fourier transform infrared (FTIR) and the self-healing property of the system is characterized by scanning electron microscope (SEM). It was found that the esterification reaction occurred in the system, and the realization of the self-healing property was also due to the transesterification reaction. In addition, the effect of the accelerator on the system is analyzed by the established autocatalysis model and dynamic mechanical analysis (DMA). The result shows that the addition of the accelerator does not change the curing reaction mechanism of the system, but accelerated the reaction process and increased the glass transition temperature.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Maoping Lu,Yingchun Liu,Xiangxiang Du,Shiheng Zhang,Guokang Chen,Qian Zhang,Sa Yao,Liyan Liang,Mangeng Lu
In this work, a cycloaliphatic epoxy resin hexahydrophthalic acid bis(3,4-epoxycyclohexylmethyl) ester (BE) was prepared and cured with anhydride. The curing kinetics and properties of the cycloaliphatic epoxy resin were characterized and compared with (3′,4′-epoxycyclohexane) methyl-3,4-epoxycyclohexyl-carboxylate (CE) and bis(3,4-epoxycyclohexylmethyl) adipate (BA). The result shows that BE/4-methyl hexahydrophthalic anhydride (MHHPA) exhibits a higher reaction activation energy and a slower curing rate than CE/MHHPA and BA/MHHPA. The loss modulus of BE/MHHPA increased 53 and 24% compared to CE/MHHPA and BA/MHHPA, respectively. The Young’s modulus and initial degradation temperature of BE/MHHPA improved 31 and 6.4% compared with those of BA/MHHPA. Furthermore, superior moisture resistance and dielectric properties are expressed for BE/MHHPA among these epoxy resins. Those results demonstrated the potential usefulness of BE/MHHPA in the electronic packaging materials field.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2013
·Vol. 57
·期 3
·379-388
·
IF 1.327
Ma SongQi,Liu XiaoQing,Jiang YanHua,Fan LiBo,Feng JianXiang,Zhu Jin
A phosphorus-containing bio-based epoxy resin (EADI) was synthesized from itaconic acid (IA) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). As a matrix, its cured epoxy network with methyl hexahydrophthalic anhydride (MHHPA) as the curing agent showed comparable glass-transition temperature and mechanical properties to diglycidyl ether in a bisphenol A (DGEBA) system as well as good flame retardancy with UL94 V-0 grade during a vertical burning test. As a reactive flame retardant, its flame-resistant effect on DGEBA/MHHPA system as well as its influence on the curing behavior and the thermal and mechanical properties of the modified epoxy resin were investigated. Results showed that after the introduction of EADI, not only were the flame retardancy determined by vertical burning test, LOI measurement, and thermogravimetric analysis significantly improved, but also the curing reactivity, glass transition temperature ( T
g ), initial degradation temperature for 5% weight loss ( T
d(5%) ), and flexural modulus of the cured system improved as well. EADI has great potential to be used as a green flame retardant in epoxy resin systems.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 6
·975
·
IF 3.164
Kexin Fu,Qing Xie,Fangcheng LÜ,Qijun Duan,Xinjie Wang,Quansheng Zhu,Zhengyong Huang
An investigation of the relationship between the microstructure parameters and thermomechanical properties of epoxy resin can provide a scientific basis for the optimization of epoxy systems. In this paper, the thermomechanical properties of diglycidyl ether of bisphenol A (DGEBA)/methyl tetrahydrophthalic anhydride (MTHPA) and DGEBA/nadic anhydride (NA) were calculated and tested by the method of molecular dynamics (MD) simulation combined with experimental verification. The effects of anhydride curing agents on the thermomechanical properties of epoxy resin were investigated. The results of the simulation and experiment showed that the thermomechanical parameters (glass transition temperature (Tg) and Young’s modulus) of the DGEBA/NA system were higher than those of the DGEBA/MTHPA system. The simulation results had a good agreement with the experimental data, which verified the accuracy of the crosslinking model of epoxy resin cured with anhydride curing agents. The microstructure parameters of the anhydride-epoxy system were analyzed by MD simulation, including bond-length distribution, synergy rotational energy barrier, cohesive energy density (CED) and fraction free volume (FFV). The results indicated that the bond-length distribution of the MTHPA and NA was the same except for C–C bonds. Compared with the DGEBA/MTHPA system, the DGEBA/NA system had a higher synergy rotational energy barrier and CED, and lower FFV. It can be seen that the slight change of curing agent structure has a significant effect on the synergy rotational energy barrier, CED and FFV, thus affecting theTgand modulus of the system.Keywords:epoxy resin;anhydride curing agents;molecular dynamics simulation;thermomechanical properties;structure-property relationship
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）