Zhou Ji, Heng Zhengguang, Zhang Haoruo, Chen Yang, Zou Huawei, Liang Mei
The State Key Lab of Polymer Materials Engineering, Polymer Research Institute of Sichuan University Chengdu 6100652 China
RSC Adv. 2019 Dec 16;9(71):41603-41615. doi: 10.1039/c9ra08098h. eCollection 2019 Dec 13.
Research on structural-functional integration of polymers has become an inevitable trend and development orientation in modern materials science. An intrinsic flame-retardant epoxy with superior mechanical properties and reusability is of great application value as a composite matrix and structural material. We newly synthesized two bio-based epoxy resins, VSE and VDE, the Young's modulus of product cured by DDM (4,4-diaminodiphenyl methane) achieve 5013 MPa and 4869 MPa, respectively. The LOI values of VSE and VDE were 38.7% and 34.5% respectively and both meet UL-94 V-0 rating. High char residue at 800 °C (34.5% and 28.0%, respectively) means a superior thermal stability which conventional epoxies are unreachable. Besides, cured VDE have convenient processability which can be re-shape as heating up and retain complete structural performance after cooling to room temperature. Furthermore, thermogravimetric analysis coupled with infrared spectroscopy (TGA-IR) and energy dispersive X-ray spectroscopy (EDS) were used to assist scanning electron microscopy (SEM) to investigate the intrinsic flame-retardant mechanism. In this work, the effect and process of nitrogen-phosphorus synergy on flame retardant is revealed finally. These results indicate the newly prepared epoxy has excellent flame retardancy, mechanical properties and recyclability which opens new possibilities in practical applications of epoxy such as coatings, potting or composite matrix in the near future.
聚合物结构-功能一体化研究已成为现代材料科学中不可避免的趋势和发展方向。一种具有优异机械性能和可重复使用性的本征型阻燃环氧树脂作为复合基体和结构材料具有巨大的应用价值。我们新合成了两种生物基环氧树脂VSE和VDE，由4,4-二氨基二苯甲烷（DDM）固化的产物的杨氏模量分别达到5013MPa和4869MPa。VSE和VDE的极限氧指数（LOI）值分别为38.7%和34.5%，均达到UL-94 V-0等级。在800℃时具有较高的残炭率（分别为34.5%和28.0%）意味着具有优异的热稳定性，这是传统环氧树脂无法达到的。此外，固化后的VDE具有便捷的加工性能，加热时可重新成型，冷却至室温后保留完整的结构性能。此外，采用热重分析联用红外光谱（TGA-IR）和能量色散X射线光谱（EDS）辅助扫描电子显微镜（SEM）来研究其本征阻燃机理。在这项工作中，最终揭示了氮-磷协同作用对阻燃的影响及过程。这些结果表明新制备的环氧树脂具有优异的阻燃性、机械性能和可回收性，这在不久的将来为环氧树脂在涂料, 灌封或复合基体等实际应用中开辟了新的可能性。
