非活性稀释剂对常温固化环氧树脂性能的影响
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摘要
采用常温、中温以及高温混合固化剂对环氧树脂首先进行常温固化,再进行环境升温诱导后固化,分析了非活性稀释剂癸二酸二丁酯对该常温固化环氧树脂固化性能的影响。通过平板小刀法、差示扫描量热分析、固化度测试以及动态力学热分析,分别评价了稀释剂对该室温固化环氧树脂的固化时间、反应过程、反应程度以及固化物耐热性能的影响,并通过三点弯曲试验分析了其复合材料室温及高温条件下的力学性能。结果表明,常温固化环氧树脂体系具有在环境升温过程中产生梯度反应的特征。而稀释剂的添加使树脂体系在25℃时的固化时间延长率为37. 5%;稀释剂有助于减缓体系内部的固化反应,提高常温固化物的固化度和储能模量,但会明显造成玻璃化转变温度的降低;经环境升温过程之后,稀释剂对固化度和储能模量的影响减弱,但玻璃化转变温度的降低幅度增大;癸二酸二丁酯作为稀释剂可显著提高环氧树脂复合材料的弯曲强度,但会减弱其高温力学性能保持能力。
The normal,medium and high temperature curing agents were combined as mixed curing agent for the room temperature curing reaction of epoxy resin,and then the post-curing was induced by the environment temperature rising process. The effects of non-reactive diluent dibutyl sebacate on the curing performance of the epoxy resin were analyzed. Flat-knife method,DSC analysis,curing degree test and DMA analysis were taken to evaluate the changes in curing time,process of curing reaction,degree of cure and thermal endurance properties,respectively. In addition,the mechanical properties at normal and high temperatures of the epoxy resin composites were studied through three-point bending test. Results show that the room temperature curing epoxy resin described in this paper possesses a key characteristic in environment temperature rising process. The gradient curing reactions are taking place in the system. After the diluent is added into this system,the extension rate of curing time reaches 37. 5% at 25 ℃. The diluent helps to reduce the rate of curing reaction,improve the curing degree and energy storage modulus of the room temperature cured epoxy,but obviously cause decrease in the glass transition temperature. After the environment temperature raising process,the influences of diluent on curing degree and energy storage modulus are weakened,however,reduce in glass transition temperature is more obvious. Dibutyl sebacate used as diluent can significantly improve the bending strength of epoxy resin composites,but is not conducive to maintain the mechanical properties at high temperature.
The normal,medium and high temperature curing agents were combined as mixed curing agent for the room temperature curing reaction of epoxy resin,and then the post-curing was induced by the environment temperature rising process. The effects of non-reactive diluent dibutyl sebacate on the curing performance of the epoxy resin were analyzed. Flat-knife method,DSC analysis,curing degree test and DMA analysis were taken to evaluate the changes in curing time,process of curing reaction,degree of cure and thermal endurance properties,respectively. In addition,the mechanical properties at normal and high temperatures of the epoxy resin composites were studied through three-point bending test. Results show that the room temperature curing epoxy resin described in this paper possesses a key characteristic in environment temperature rising process. The gradient curing reactions are taking place in the system. After the diluent is added into this system,the extension rate of curing time reaches 37. 5% at 25 ℃. The diluent helps to reduce the rate of curing reaction,improve the curing degree and energy storage modulus of the room temperature cured epoxy,but obviously cause decrease in the glass transition temperature. After the environment temperature raising process,the influences of diluent on curing degree and energy storage modulus are weakened,however,reduce in glass transition temperature is more obvious. Dibutyl sebacate used as diluent can significantly improve the bending strength of epoxy resin composites,but is not conducive to maintain the mechanical properties at high temperature.
引文
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[5]李玉彬,张佐光,袁宇慧,等.稀释剂对环氧树脂电子束辐射固化性能的影响[J].复合材料学报,2007,24(3):94-99.Li Y B,Zhang Z G,Yuan Y H,et al. Effect of diluent on the curing characterization of electron beam cured epoxy resins[J]. Acta Materiae Compositae Sinica,2007,24(3):94-99.
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[8]林益军,邓青华,金日光.稀释剂对BPA型环氧树脂188EL及其固化物性能的影响[J].热固性树脂,2014,29(4):19-22.Lin Y J,Deng Q H,Jin R G. Effects of diluent on the properties of BPA epoxy resin 188EL and its cured product[J]. Thermosetting Resin,2014,29(4):19-22.
[9] Geng H T,Liu J C,Ren S. Effects of diluent on mechanical properties of hollow glass microsphere reinforced epoxy resin composite[J]. Key Eng. Mater.,2016,680:525-528.
[2]白天,郭安儒,李瑞杰,等.稀释剂对耐高温环氧树脂性能的影响[J].应用化学,2016,33(12):1401-1407.Bai T,Guo A R,Li R J,et al. Effect of diluent on performances of high-temperature resistance epoxy resin[J]. Chinese Journal of Applied Chemistry,2016,33(12):1401-1407.
[3]邱建华,腾新华,邵银存,等.活性稀释剂-环氧树脂体系性能研究[J].中国胶黏剂,2012,21(5):21-24.Qiu J H,Teng X H,Shao Y C,et al. Study on properties of reactive diluent-EP system[J]. China Adhesives,2012,21(5):21-24.
[4] Núez-Regueira L,Villanueva M,Fraga-Rivas I. Effect of a reactive diluent on the curing and dynamomechanical properties of an epoxy-diamine system[J]. J. Therm. Anal. Calorim.,2006,86:463-468.
[5]李玉彬,张佐光,袁宇慧,等.稀释剂对环氧树脂电子束辐射固化性能的影响[J].复合材料学报,2007,24(3):94-99.Li Y B,Zhang Z G,Yuan Y H,et al. Effect of diluent on the curing characterization of electron beam cured epoxy resins[J]. Acta Materiae Compositae Sinica,2007,24(3):94-99.
[6] Min B G,Stachurski Z H,Hodgkin J H. Cure kinetics of elementary reactions of a DGEBA/DDS epoxy resin:1. Glass transition temperature versus,conversion[J]. Polymer,1993,34:4908-4912.
[7] Dodiuk H,Kenig S. Room temperature curing epoxy and their elevated-temperature properties[J]. Macromol. Symp.,1992,53:105-124.
[8]林益军,邓青华,金日光.稀释剂对BPA型环氧树脂188EL及其固化物性能的影响[J].热固性树脂,2014,29(4):19-22.Lin Y J,Deng Q H,Jin R G. Effects of diluent on the properties of BPA epoxy resin 188EL and its cured product[J]. Thermosetting Resin,2014,29(4):19-22.
[9] Geng H T,Liu J C,Ren S. Effects of diluent on mechanical properties of hollow glass microsphere reinforced epoxy resin composite[J]. Key Eng. Mater.,2016,680:525-528.