具有高效催化交联成炭性能的层状双氢氧化物(LDH)的制备及在聚烯烃中的阻燃、增强机理研究

Improving carbon sequestration ability of the flame retardant system, promoting more polymer molecules to involve in the formation of the final char residue, improving the quality of the carbon layer and lowering the loading amount of flame retardants are the effective measures to solve flame retardancy and mechanical processing performance of polyolefin. According to the principle of “efficient catalytic crosslinking carbonization”, The project plans to synthesize a long chain ferrocene-containing intumescent flame retardant and smoke suppressant (IFS) with efficient self-catalytic crosslinking char-formation ability; through the regulation of different metal ions, a series of novel organic/inorganic hybrid layered double hydroxide (LDH-IFS) with high efficiency catalytic char-formation performance will be prepared by using IFS anion as intercalation agent, which will remarkably increase the dispersibility and exfoliation of LDH layers in polymer matrix, and enhance the flame retarding efficiency and mechanical properties of polyolefin material。 . The char-fomation mechanism of IFS will be detailedly investigated. The char-formation efficency matching and synergistic catalytic crosslinking mechanism between various metal ions and IFS will be illuminated in depth. The effect factor of LDH on the quality of resulting char residue will also be analysized. Based on the above discussion, the catalyzed crosslinking char-formation mechanism between polyolefin molecules and LDH-IFS will be put forward. All results and data obtained in this project will provide a novel exploration for the development of analogous flame retardant with high-efficient catalyzed char-formation and mechanical strengthening performance, which is beneficial to further develop and enrich non-halogen flame retardant theories.

提高阻燃体系的固碳能力、促进更多的聚合物分子参与最终炭层的形成、改善炭层的质量、降低阻燃剂的添加量是解决聚烯烃材料阻燃和力学加工性能的有效途径。根据“催化交联成炭”原理，本项目设计并合成具有高效自催化交联成炭性能、含二茂铁的新型长链膨胀型阻燃抑烟剂（IFS）。利用IFS阴离子作为插层剂，通过调控金属离子的种类和组成，制备系列新型具高效催化成炭功能的层状双氢氧化物基有机/无机杂化纳米阻燃剂（LDH-IFS），从而有效提高LDH层板在聚合物基体中的分散剥离状态，增强聚烯烃材料的阻燃效率和力学性能。深入探讨IFS的成炭机理，阐明LDH中金属离子种类及含量与IFS之间的匹配性、协效催化交联成炭原理，分析LDH对最终炭层质量的影响因素，提出LDH-IFS催化聚烯烃分子参与交联成炭的作用机理。这将为发展类似具有高效催化成炭和力学增强功能的阻燃剂提供一种新探索，进一步深化和完善无卤阻燃抑烟理论。

1、 以硝酸锌（Ni(NO3)2·6H20），硝酸镍（Zn(NO3)2·6H20），硝酸铝（Al(NO3)3·9H20）和尿素为原料，通过水热法制备了锌镍铝三元层状双氢氧化合物（N-LDH）。选用含有阻燃元素N和具有高温自交联官能团（N=N）的化合物偶氮苯二甲酸，通过离子交换法对LDH进行插层改性，制备了有机化改性LDH(O-LDH)。将O-LDH作为一种新型的阻燃协效剂与膨胀型阻燃剂（IFR）复配，制备不同配比的聚丙烯（PP）阻燃复合材料。通过LOI、UL-94和CC等测试方法对PP复合材料的阻燃抑烟性能和燃烧行为进行了表征。LOI和UL-94结果表明LDH与IFR之间具有协效阻燃作用。PIOL1复合材料的氧指数能达到29.3%，并达到UL-94 V-0级。锥形量热结果表明，O-LDH的加入能明显改善PP的防火性能，并对阻燃机理进行了探讨。.2、设计并合成了一种可使环氧树脂在阻燃性能、力学性能和耐热性能方面保持平衡的阻燃剂a-SEP@LDH（a-SEP，海泡石纳米纤维；LDH，Ni-Fe LDH）。当单独添加2.3 wt%的a-SEP@LDH时，EP复合材料达V-1级，峰值热释放速率和总烟释放分别下降21%和16%，拉伸强度和玻璃化转变温度(Tg)均提高。为增强a-SEP@LDH的阻燃效率，将a-SEP@LDH与含磷、氮元素纳米片复配；EP复合材料达V-0级，拉伸强度和玻璃化转变温度(Tg)也得以提高。同时，分析了两种EP复合材料的阻燃和增强机理。.3、通过一步共沉淀法，采用生物基材料植酸（PA）和叶酸（FA）分别对ZnNiAl-LDH进行改性得到PA-LDH和FA-LDH纳米片。然后通过XRD和FTIR表征手段证明PA-LDH和FA-LDH被成功制备。最后通过TEM表征方法证实PA-LDH和FA-LDH的纳米片微观形貌。.4、采用一步裂解二茂铁基阻燃剂（PDPFDE）制备了含铁碳基纳米复合材料，探讨了不同裂解温度、不同裂解时间下其对碳基纳米复合材料结构的影响。计算不同含铁碳基纳米复合材料的RL性能、电磁性能、ε"-ε'曲线、衰减常数α、μ''(μ')-2f-1曲线和Z值。结果表明：650℃-2h碳基纳米复合材料是以介电损耗为主要的损耗机制，吸收性能好是源于好的阻抗匹配，以及磁损耗、介电驰豫损耗、电导损耗以及多重散射的协同效应。