Self-healing properties of epoxy resins with poly(ε-caprolactone) healing agent
Self-healing properties of epoxy resins with poly(ε-caprolactone) healing agent
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DOI：
10.1007/s00289-016-1642-2
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发表时间：
2016-11-01
期刊：
影响因子：
3.2
通讯作者：
Karger-Kocsis, J.
中科院分区：
文献类型：
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作者：
Karger-Kocsis, J.
通过热塑性聚（ε-己内酯）（PCL），溶解在12.5%，25%，37.5%和50%（重量），分别在胺固化的环氧树脂（EP）的热诱导愈合进行了研究紧凑的拉伸（CT）标本。用相同的胺（Jeffamine D 230）固化芳族（双酚A型的氢化二缩水甘油醚）和脂族（甘油-三缩水甘油醚）EP以获得具有不同玻璃化转变温度（T（g））的EP。母体EP的T（g）值分别低于（T（g）= 32 A ℃）和高于（T（g）= 90 A ℃）PCL的熔融温度（T（m）ae 60 A ℃）。用光学显微镜研究了聚己内酯的固化诱导相分离形态。从动态力学分析中推导出有关相结构的其他信息。与PCL共混降低了相应EP的T（g）。完全断裂的CT试样在接近或高于EP/PCL共混物的实际T（g）的80 A ℃下反复愈合。结果表明，PCL从分散相向连续相的转变不仅取决于PCL的用量，还与EP的类型及其固化有关。EP/PCL系统具有半互穿网络结构（双连续）表现出显着更高的愈合效率相比，其中PCL作为分散相存在。愈合效率还取决于愈合温度与EP的T（g）相对于PCL的T（m）之间的温差。当T（g）> T（m）时，则相关差异应保持较小，而对于T（g）< T（m），温度差异应较大以支持愈合。因此，交联EP网络内的链段流动性也是热修补的关键参数。
Thermally induced healing through thermoplastic poly(epsilon-caprolactone) (PCL), dissolved in 12.5, 25, 37.5 and 50 wt%, respectively, in amine-cured epoxy resins (EPs) was studied on compact tension (CT) specimens. Aromatic (hydrogenated diglycidyl ether of bisphenol A-type) and aliphatic (glycerol-triglycidylether) EPs were cured with the same amine (Jeffamine D 230) to receive EPs with different glass transition temperatures (T (g)). T (g) values of the parent EPs were lower (T (g) = 32 A degrees C) and higher (T (g) = 90 A degrees C), respectively, than the melt temperature (T (m) ae 60 A degrees C) of the PCL. The curing-induced phase separation morphology of PCL was studied by light microcopy. Additional information on the phase structure was deduced from dynamic mechanical analysis. Blending with PCL reduced the T (g) of the corresponding EPs. Fully broken CT specimens were repeatedly healed at 80 A degrees C which was close to or higher than the actual T (g) of the EP/PCL blend. It was found that the transition of PCL from disperse to continuous phase depends not only on the PCL amount, but also on the EP type and its curing. EP/PCL systems with semi-interpenetrating network structure (bi-continuous) exhibited markedly higher healing efficiencies compared to those in which PCL was present as disperse phase. The healing efficiency depended also on the temperature difference between the healing temperature and T (g) of the EP with respect to T (m) of PCL. When T (g) > T (m) then the related difference should be kept small, while for T (g) < T (m) the temperature difference should be large to support healing. Accordingly, the segmental mobility within the cross-linked EP network is a key parameter for thermal mending, too.