The effects of nano- and molecularly-dispersed additives on the flame retardance in some chain-growth polymers containing covalently bound phosphorus

仅在英国，不必要的火灾就造成数百人死亡（约600人死亡，16，000人非致命伤亡），每年约50亿英镑，给我们的工业和社会带来巨大的损失。吸入烟雾和有毒气体占死亡人数的50%，烧伤占31%，其余为火灾相关因素的组合。其中许多死亡发生在涉及燃烧聚合物基材料的火灾中，这些材料要么是火灾的主要来源，要么是火灾蔓延的主要原因。显然，合成阻燃性更强的聚合物材料在降低未来此类死亡的规模方面发挥着重要作用。消防安全措施和不断上升的保险费（估计为GDP的1%）所带来的无形成本对经济造成了巨大的消耗。此外，为了应对特定的威胁，例如恐怖主义行动造成的火灾和公共建筑的安全，我们必须了解意外火灾的行为。（甲基丙烯酸甲酯）、聚苯乙烯、聚丙烯腈和其它具有商业意义的链反应聚合物，用含磷基团反应性改性，其物理和机械性能不明显劣于未改性的对应物，但具有可调的阻燃性（冷凝相与汽相），以使它们特别适合于阻燃涂料、纺织品、粘合剂和热塑性模塑材料中的应用。我们还提出将纳米粘土，如蒙脱土，在用含磷基团反应性改性的聚合物中，目的是在燃烧过程中将阻燃剂部分更长时间地保留在凝聚相中，从而改变气相和凝聚相阻燃机理之间的平衡，有利于凝聚相。我们建议引入到我们的阻燃聚合物中的另一种纳米级添加剂是三聚氰胺。三聚氰胺作为一种发泡剂，可以提高焦炭作为燃烧屏障的有效性。我们还打算探讨的影响，引入环糊精（CD）到改性聚合物。CD是环状低聚糖，与纤维素和其他多糖一样，是良好的成炭剂。我们认为，这是一条新的途径，将在方案的后半部分进行系统的探索，以期确定在这些复合材料中起作用的协同效应，最后，将从热解的气相产物的分析中获得关于机制的详细资料。从研究中获得的结果预计将有助于在合理的科学基础上制定新的防火材料。我们相信，在更广泛的意义上，这将导致更好的阻燃聚合物的方法。

Unwanted fires in the UK alone cost hundreds of lives (about 600 deaths and 16,000 non-fatal casualties) and about 5.0 billion per year, placing a huge drain on our industry and society. The inhalation of smoke and toxic gases accounted for 50% of the deaths, burns for a further 31%, and a combination of fire-related factors for the remainder. Many of these deaths occurred in fires in which burning polymer-based materials were implicated, either as the primary source of the fire or as a major contributor to the proliferation of the fire. Clearly, the synthesis of polymeric materials that are more flame-retardant has an important part to play in reducing the scale of such deaths in future.The invisible cost through fire safety measures and escalating insurance premiums (estimated as 1% of GDP) is a massive drain on the economy. In addition, in order to address specific threats, such as fire resulting from terrorist action and safety in public buildings, it is essential to develop our understanding of the behaviour of unwanted fires.The overall aim of the project is to prepare poly(methyl methacrylate)s, polystyrenes, polyacrylonitriles and other chain-reaction polymers of commercial significance, reactively modified with phosphorus-containing groups, having physical and mechanical properties not significantly inferior to those of the unmodified counterparts, but with tunable flame-retardance (condensed-phase vs. vapour-phase) to suit them for applications particularly in flame-retardant coatings, textiles, adhesives and thermoplastic moulding materials.We also propose to disperse nanoclays, such as montmorillonite, in polymers reactively modified with phosphorus-containing groups with the aim of retaining the flame retardant moieties longer in the condensed phase during combustion, thus altering the balance between vapour-phase and condensed-phase mechanisms of flame retardation in favour of the condensed phase. A further nanoscopic additive we propose to introduce into our flame-retarded polymers is melamine. Melamine acts as a spumific and can enhance the effectiveness of chars as barriers to combustion. We also intend to explore the effect of introducing cyclodextrins (CDs) into the modified polymers. CDs are cyclic oligomeric sugars and, like cellulose and other polysaccharides, are good char-forming agents. This, we believe, is a novel route which will be systematically explored during the latter part of the programme with a view to identifying the synergistic effects, if any, operating in these composite materials.Finally, detailed information on mechanisms will be obtained from analyses of the gas-phase products of pyrolysis. The results obtained from the study is expected to aid in formulating of novel fire-safe materials on a sound scientific base. This we beleive, in the broader sense, would lead to better ways of flame retarding polymers.