采用乳液工艺,对天然橡胶(NR)依次进行环氧化和开环接枝改性,引入多重氢键和悬挂链,结合NR优异的高弹性,制备了具有自修复性能的接枝天然橡胶(GENR)。采用红外光谱仪、核磁共振氢谱仪、光学显微镜、万能拉伸机和动态粘弹谱仪分析了接枝产物的改性程度及改性程度和修复条件对修复效率的影响。结果表明:反应温度50℃,pH=5的反应条件下改性程度可达20.8%(摩尔分数),且几乎没有副反应发生。1.0mm厚的GENR 20.8片材在50℃无任何外力下21min即可基本修复断面。GENR 20.8在室温和50℃下分别修复2h,修复效率分别达到了50.6%和81.5%,显示出温和温度条件下快速、高效的自修复能力。氢键网络、弹性恢复以及悬挂链间的物理缠绕是本体系自修复的主要机制。
The natural rubber (NR) was modified by epoxidation and grafting in order through emulsion process.The introduction of multiple hydrogen bonding and pendent group,combined with excellent high elasticity of NR,the grafted natural rubber (GENR) showed self-healing performance.Infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H-NMR) were used to analysis the degree of modification.Optical microscope (OM),universal tensile testing machine and dynamic viscoelastic spectrometer were used to evaluate the effect of degree of modification and self-healing conditions on the self-healing efficiency of GENR 20.8.The results showed that under the reaction conditions of 50℃ and pH=5,the modification degree was 20.8mol% and almost no side reactions occurred.The OM results showed that GENR 20.8 surfaces could self-healed in 21min basically in the absence of any external force.After the two sections of GENR 20.8 contacted at room temperature and 50℃ respectively for 2h,the self-healing efficiency were up to 50.6% and 81.5% separately,suggesting a rapid and efficient self-healing ability under mild temperature condition.The main self-healing mechanisms for this system were the hydrogen bond network,physical entanglement between pendent groups and elastic nature of NR.
[1] 刘坚.天然橡胶的化学改性[J].特种橡胶制品,2001,22(3):51,57-60.
[2] 李学岱,杨清芝,张殿荣.环氧化天然橡胶的基本性能[J].弹性体,1992,2(4):45-53.
[3] 余和平,李思东.环氧化天然橡胶研究进展[J].橡胶工业,1998,45(4):246-252.
[4] Kookarinrat C,Paoprasert P.Versatile one-pot synthesis of grafted-hydrogenated natural rubber[J].Iranian Polymer Journal,2015,24(2):123-133.
[5] Watcharakul N,Poompradub S,Prasassarakich P.In situ silica reinforcement of methyl methacrylate grafted natural rubber by sol-gel process[J].Journal of Sol-Gel Science and Technology,2011,58(2):407-418.
[6] Mohapatra S,Nando G B.Chemical modification of natural rubber in the latex stage by grafting cardanol,a waste from the cashew industry and a renewable resource[J].Industrial & Engineering Chemistry Research,2013,52(17):5951-5957.
[7] Kosugi K,Sutthangkul R,Chaikumpollert O,et al.Preparation and characterization of natural rubber with soft nanomatrix structure[J].Colloid & Polymer Science,2012,290(14):1457-1462.
[8] 李思超,韩朋,许华平.自修复高分子材料[J].化学进展,2012,24(7):1346-1352.
[9] Zhang Mingqiu,Rong Minzhi.Design and synthesis of self-healing polymers[J].Science China Chemistry,2012,55(5):648-676.
[10] 赵翰文,冯利邦,史雪婷,等.热可逆自修复环氧树脂的合成与修复行为[J].高分子学报,2017(12):1-6.
[11] 张兴才,容敏智,章明秋.自修复材料研究进展[J].宇航材料工艺,2006(1):1-4,63.
[12] Rahman M A,Sartore L,Bignotti F,et al.Autonomic self-healing in epoxidized natural rubber[J].ACS Applied Materials and Interfaces,2013,5(4):1494-1502.
[13] 向洪平,容敏智,章明秋.硫化天然橡胶的本征自修复与固相回收加工[J].高分子学报,2017(7):1130-1140.
[14] 余锡宾,吴虹.正硅酸乙酯的水解、缩合过程研究[J].无机材料学报,1996,11(4):703-707.
[15] 罗章,李斌,姚薇,等.环氧化天然橡胶二次改性的研究进展[J].高分子通报,2016(6):38-43.
[16] 王慧,张秀凤,栗付平,等.用高锰酸钾氧化法制备液体天然橡胶[J].合成橡胶工业,2016,39(1):29-32.
[17] 辛帅,孙超,马凤国.正硅酸乙酯法乙烯基MQ硅树脂的结构及热性能研究[J].有机硅材料,2016,30(3):181-185.
[18] 李承斌,王辉,冯喆,等.原位法制备环氧化天然橡胶及其表征[J].化工新型材料,2012,40(3):124-126,130.
[19] 张治国,尹红.环氧乙烷和环氧丙烷开环聚合[J].化学进展,2007,19(1):145-152.
[20] 冯玉红,李嘉诚,黄宝琛,等.环氧化反式-1,4-聚异戊二烯的合成[J].昆明理工大学学报(理工版),2002,27(4):138-142.
[21] Antonio Feula,Alexander Pethybridge,Ioannis Giannakopoulos,et al.A thermoreversible supramolecular polyurethane with excellent healing ability at 45℃[J].Macromolecules,2015,48(17):6132-6141.
基金资助
“十三五”国家重点研发计划课题(2017YBF0306902);中国科学院合成橡胶重点实验室开放课题(KLSR201702)
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