基于物理交联和π-π共轭协同作用的新型脂肪族聚碳酸酯类弹性体制备及自修复性能研究

Preparation and Self-healing Properties of New Aliphatic Polycarbonate Elastomers with Physical Crosslinking andπ-π-Conjugated Synergy

利用物理交联相互作用开发具有自修复性能的弹性体是提高材料使用寿命有效方法之一,然而,这类弹性体的机械性能与自修复性能是相互矛盾的。在这项工作中,首先制备了5-甲基-5-苄氧羰基二亚甲基碳酸酯(MBC)和5-甲基-5-(4-硝基)苄氧羰基二亚甲基碳酸酯(MNBC),然后利用mPEG与MBC和MNBC通过开环聚合获得目标材料,并确定了弹性体的最佳制备工艺。其次,采用红外、核磁和示差扫描量热分析(DSC)分别测试了材料的化学结构和热行为,并探讨了脂肪族聚碳酸酯形成凝胶的交联机理,通过改变引发剂与单体比例,单体之间的比例和反应温度来调控此类材料由线性聚合物向网络弹性体的转变。同时,利用平衡溶胀法、动态热力学分析等手段表征了弹性体溶胀行为、凝胶含量、溶胀率、含水量和力学性能。此外,通过弯曲实验,验证了弹性体具有一定的形状记性性能,并且通过划痕实验验证了弹性体具有良好的室温自修复性能,该研究也为弹性体后期的应用打下良好的性能基础。

To improve the life of materials,using physical cross-linking interaction to develop self-healing elastomers is one of the effective ways.However,the mechanical properties and self-healing properties of the elastomers are contradictory.In this study,5-methyl-5-benzyloxycarbonyl dimethylene carbonate(MBC)and 5-methyl-5-(4-nitro)benzyloxycarbonyl dimethylene carbonate(MNBC)were first prepared,and then the target materials were obtained by ring-opening polymerization with mPEG and MBC and MNBC,and the best preparation process was determined.The chemical structure and thermal behavior of aliphatic monomers and polycarbonate were characterized by infrared spectroscopy,nuclear magnetic resonance spectroscopy and differential scanning calorimetry(DSC).The crosslinking mechanism of aliphatic polycarbonate forming gel was discussed.The transition from linear polymer to network elastomer is controlled by adjusting the ratio of initiator to monomer,the ratio between monomers and the reaction temperature.Meanwhile,the swelling behavior,gel content,swelling rate,water content and mechanical properties of the elastomer were characterized by means of equilibrium swelling method and dynamic thermodynamic analysis.In addition,the bending experiment verifies that the elastomer has a certain shape memory performance,and the scratch experiment verifies that the elastomer has a good room temperature Self-healing performance.