超高分子量聚乙烯纤维的无卤阻燃整理

为提高超高分子量聚乙烯(UHMWPE)纤维的阻燃性能,采用兼具阻燃和抑烟作用的氢氧化镁包覆碳微球(MH-CMSs)作为阻燃剂,以钛酸四丁酯和亚磷酸三苯酯作为活化剂,依次通过除杂—活化—浸轧—烘焙的方法对UHMWPE纤维进行阻燃改性。测试了纤维的阻燃性能、力学性能以及热稳定性,研究其阻燃作用机制。结果表明:该方法能在不损害UHMWPE纤维力学性能的同时有效提高其阻燃性能;与纯UHMWPE纤维相比,经阻燃整理后得到的FR-UHMWPE纤维的极限氧指数(LOI值)可提高36%以上,峰值热释放速率降低幅度达39.3%,且纤维的发烟和熔滴现象也得到改善,火灾危险性显著降低;FR-UHMWPE纤维表现出凝聚相阻燃机制,阻燃整理促进了UHMWPE热降解成炭,使其在燃烧时形成了致密连续的炭层,该炭层能有效阻止热与质的传递,从而起到阻燃作用。

Halogen-free flame retardant finishing of ultra-high molecular weight polyethylene fiber

In order to improve the flame retardant properties of ultra-high molecular weight polyethylene (UHMWPE) fiber, carbon microspheres coated by magnesium hydroxide (MH-CMSs), which have both flame retardant and smoke suppression effect, were used as flame retardants, and tetrabutyl titanate and triphenyl phosphite were used as surfactants. The UHMWPE fibers were modified using the procedure of impurity removal—activation—padding—baking. The flame retardant properties, mechanical properties and thermal stability of these fibers were tested, and the flame retardant mechanism was studied. The research results show that this method is able to improve effectively the flame retardancy of UHMWPE fiber without harming its mechanical properties. Compared with pure UHMWPE fiber, the limited oxygen index of flame retardant UHMWPE (FR-UHMWPE) fiber is increased more than 36%, the peak heat release rate is reduced by up to 39.3%. In addition, smoke and molten droplets of the UHMWPE fibers are suppressed, and the fire risk is significantly reduced. The FR-UHMWPE fiber exhibits condensed phase flame retardant mechanism. The flame retardant finishing promotes the degradation of UHMWPE into carbon, which forms a dense and continuous char layer during the combustion process. This char layer can effectively prevent the transfer of heat and mass, and thus has a flame retardant effect.