STUDY ON CURING KINETICS OF TOUGHENED MODIFIED EPOXY RESIN AND DRAWING OF TTT DIAGRAM

Abstract

Abstract: In this study, the gelation and vitrification behavior of toughened modified epoxy resin were measured by small amplitude oscillatory shear method and differential scanning calorimetry, respectively, and the time-temperature-transition (TTT) diagram of the epoxy system was established. A dynamic differential scanning calorimetry (DSC) experiment was carried out on the toughened modified epoxy resin system, and a curing kinetic model was established using a phenomenological model. Using isothermal DSC and dynamic DSC combined with DiBenedetto equation to study the relationship between resin glass transition temperature and degree of curing, and gives the mathematical relationship between the glass transition temperature T_g and time t and temperature T. The gel time at different temperatures of the resin system was tested using a flat plate rheometer, and the relationship between the gel time and temperature was obtained by linear regression analysis. The TTT diagram based on the toughened modified epoxy resin system is drawn to provide theoretical guidance for the molding process of epoxy resin and its prepreg, which is conducive to improving manufacturing efficiency.

Key words: epoxy resin toughening, curing kinetics, glass transition temperature, gel point, TTT diagram, composites

CLC Number:

TB332

TAO Lei, MIN Wei, QI Liang-liang, SUN Ze-yu. STUDY ON CURING KINETICS OF TOUGHENED MODIFIED EPOXY RESIN AND DRAWING OF TTT DIAGRAM[J]. Composites Science and Engineering, 2020, 0(10): 21-29.

References

[1] SUN Z, XIAO J, TAO L, et al. Preparation of high-performance carbon fiber-reinforced epoxy composites by compression resin transfer molding[J]. Materials, 2018, 12(1). DOI: 10.3390/ma12010013.
[2] PECORA M, PANNIER Y, LAFARIEFRENOT M C, et al. Effect of thermo-oxidation on the failure properties of an epoxy resin[J]. Polymer Testing, 2016, 209-217.
[3] 刘万双. 汽车轻量化用碳纤维复合材料国内外应用现状[J]. 纺织导报, 2016(5): 48-52.
[4] SUN Z, XU L, CHEN Z, et al. Enhancing the mechanical and thermal properties of epoxy resin via blending with thermoplastic polysulfone[J]. Polymers, 2019, 11(3). DOI: 10.3390/polym11030461.
[5] 刘天舒, 陈祥宝, 张宝艳. 5228高温固化环氧树脂体系的固化反应动力学研究[C]//第十三届全国复合材料学术会议. 2004.
[6] FRANCIS B. Cure kinetics of epoxy/thermoplastic blends[M]. Springer International Publishing, 2017.
[7] PASCAULT J P, WILLIAMS R J J. Thermosetting polymers[M]//Handbook of Polymer Synthesis, Characterization, and Processing. 2013.
[8] NU＇EZ L, FRAGA F, CASTRO A, et al. TTT cure diagram for an epoxy system diglycidyl ether of bisphenol A/1,2 diamine cyclohexane/calcium carbonate filler [J]. Polymer, 2001, 42(8): 3581-3587.
[9] TUNG C I M, DYNES P J. Relationship between viscoelastic properties and gelation in thermosetting systems[J]. Journal of Applied Polymer Science, 1982, 27(2): 569-574.
[10] ENNS J B, GILLHAM J K. Time-temperature-transformation (TTT) cure diagram: Modeling the cure behavior of thermosets[J]. Journal of Applied Polymer Science, 1983, 28(8): 2567-2591.
[11] CADENATO A, SALLA J M, RAMIS X, et al. Determination of gel and vitrification times of thermoset curing process by means of TMA, DMTA and DSC techniques-TTT diagram[J]. Journal of Thermal Analysis, 1997, 49(1): 269-279.
[12] GONIS J, SIMON G P, COOK W D. Cure properties of epoxies with varying chain length as studied by DSC[J]. Journal of Applied Polymer Science, 1999, 72(11): 1479-1488.
[13] YANG L F, YAO K D, KOH W. Kinetics analysis of the curing reaction of fast cure epoxy prepregs[J]. Journal of Applied Polymer Science, 1999, 73(8): 1501-1508.
[14] YANG R T, STEINBERG M. Reaction kinetics and differential thermal analysis[J]. Journal of Physical Chemistry, 1976, 80(9): 965-968.
[15] TANAKA N, IIJIMA T, FUKUDA W, et al. Synthesis and properties of interpenetrating polymer networks composed of epoxy resins and polysulphones with cross-linkable pendant vinylbenzyl groups[J]. Polymer International, 1997, 42(1): 95-106.
[16] DIBENEDETTO A T. Prediction of the glass transition temperature of polymers: A model based on the principle of corresponding states[J]. Journal of Polymer Science Part B Polymer Physics, 1987, 25(9): 1949-169.
[17] RAMIS X, CADENAT O A, MORANCHO J M, et al. Curing of a thermoset ting powder coating by means of DMTA, TMA and DSC[J]. Polymer, 2003, 44(7):2067-2079.