【摘要】 研究了不同分子量的聚己内酯的辐照特性,聚已内酯(PCL)的分子量越大,辐射交联所需的凝胶化剂量越低。结果表明,溶胶分数s+s与1/D的关系很好地符合Charlesby-Pinner关系式,说明PCL的辐射交联属于无规交联。辐射交联对PCL的力学性能影响显著,辐射剂量越大,拉伸强度和断裂伸长率下降越多,但分子量较高的PCL的抗张强度受辐射剂量的影响较小。动态力学分析(DMA)分析表明,聚己内酯辐照交联后的弹性模量和耐热性能显著提高。更多还原

【Abstract】 The γ-radiation effects on polycaprolactones with different molecular weight were investigated. It was concluded that PCL was able to be radiation cross-linked, and the dose of gelation decreased with the increasing of molecular weight. The relation between sol fraction s+sand the reciprocal of radiation dosage (1/D) meets Charlesby-Pinner formula. This indicates that the radiation cross-linking of PCL follows the theory of random cross-linking. Mechanical properties of radiated PCL were determined. The tensile strength and elongation at break declined with increasing doses, but the dose effects on tensile strength of high molecular weight PCL were as severe as low molecular weight PCL. Dynamic mechanical analysis showed that the heat distortion resistance and the temperature of abrupt drop point for tensile modulus E′ increased markedly with the irradiation dose.更多还原