本文選題：熱導率　切入點：阻燃　出處：《北京化工大學》2015年碩士論文

【摘要】：高分子復合材料由于質(zhì)輕、易加工成型、耐磨損、易于工業(yè)化等特點得到廣泛應用,但絕大多數(shù)高分子材料因?qū)嵯禂?shù)低而在應用上受到極大限制。因此,給予高分子材料良好的熱傳導能力,可以極大程度上拓寬其應用領域；在高分子復合體系具有良好熱傳導能力的基礎上保證其絕緣性,則對于提高電氣及微電子器件的精度、壽命和滿足現(xiàn)實中大量絕緣散熱場合的需求具有重大積極意義。通常為獲取高熱導率而采取的高填充導熱填料方法,會使共混體系的力學性能受到損害。另一方面,高性能塑料的易燃性是其應用過程中的最大隱患。為避免不必要事故發(fā)生,高分子材料的阻燃能力成為衡量其應用價值的重要標準。因此,制備高導熱、良絕緣、阻燃效果出色、力學性能優(yōu)良的多功能性復合材料具有重大意義。具體研究內(nèi)容如下：1.首先通過熔融混煉法制備Mg(OH)2/PP兩相共混體系,表征其導熱、阻燃、絕緣和力學性能,并通過SEM觀察其微觀形貌。實驗結果表明,Mg(OH)2添加量達到70 wt%時,共混體系的導熱系數(shù)提升至0.92 W/(m*k),比純PP增加了4.1倍；當Mg(OH)2添加量超過60 wt%,共混體系的垂直燃燒等級為UL-94 V-0級,抑煙效果良好；Mg(OH)2的加入不會損害PP良好的絕緣性；SEM照片顯示,六角片狀的Mg(OH)2顆粒在PP基體中分布均勻,無團聚現(xiàn)象；力學測試表明,在高填充量下,共混體系的彎曲性能有所提高,但各項拉伸測試結果以及缺口沖擊強度都顯著下降。2.制備了Mg(OH)2/PP/GNPs三元共混體系,對其導熱、導電、阻燃及力學性能分別展開表征,并通過SEM觀察其微觀形貌。實驗結果表明,以少量GNPs代替Mg(OH)2后,共混體系的熱傳導能力即得到顯著提升。Mg(OH)2添加量為61 wt%、GNPs添加量為9 wt%時,共混體系導熱系數(shù)由0.92 w/(m+k)提升至1.58 w/(m*k);GNPs添加量不超過9 wt%時,共混體系具有優(yōu)異的絕緣性；少量GNPs的加入使共混體系的拉伸性能和抗沖擊性能有小幅度提升,并且保持了優(yōu)異的阻燃效果。3.選用凱夫拉纖維(KF)和聚乙烯-辛烯共聚物(POE)提高共混體系的力學性能。采用熔融擠出法制備Mg(OH)2/PP/增韌填料三相共混體系,比較凱夫拉纖維與POE各自對于共混體系缺口沖擊強度、斷裂伸長率的改善效果以及對導熱、絕緣、阻燃性能的影響。實驗結果表明,凱夫拉纖維和POE的使用明顯改善了共混體系的沖擊韌性,解決了高填充Mg(OH)2所導致的聚丙烯脆性問題,且沒有影響共混體系的導熱、絕緣和阻燃效果,使本研究具有了重要的實用價值。
[Abstract]:Polymer composites are widely used because of their light weight, easy processing, wear resistance and easy industrialization. However, most polymer materials are greatly limited in application because of their low thermal conductivity.Therefore, giving good thermal conductivity to polymer materials can greatly broaden its application field, and ensure its insulation on the basis of good thermal conductivity of polymer composite system.It is of great significance to improve the accuracy and life of electrical and microelectronic devices and to meet the needs of a large number of insulation and heat dissipation occasions in reality.In order to obtain high thermal conductivity, the mechanical properties of the blends will be damaged by the method of high filling thermal conductivity.On the other hand, the flammability of high-performance plastics is the biggest hidden danger in its application.In order to avoid unnecessary accidents, the flame retardant ability of polymer material has become an important standard to measure its application value.Therefore, it is of great significance to prepare multifunctional composites with high thermal conductivity, good insulation, excellent flame retardant effect and excellent mechanical properties.The specific contents of the study are as follows: 1.Firstly, Mg(OH)2/PP two-phase blend was prepared by melt mixing method, and its thermal conductivity, flame retardancy, insulation and mechanical properties were characterized, and its microstructure was observed by SEM.The experimental results show that the thermal conductivity of the blends increases to 0.92 W / m ~ (-1), 4.1 times higher than that of pure PP when the content of MgO _ (2) is 70 wt%, and the vertical combustion grade of the blends is UL-94 V-0 when the content of Mg(OH)2 is more than 60 wt.The addition of MgOH2 to PP does not damage the good insulation of PP. The results show that the hexagonal Mg(OH)2 particles are uniformly distributed in the PP matrix and have no agglomeration, and the mechanical tests show that the Hexagonal Mg(OH)2 particles are distributed uniformly in the PP matrix, and the mechanical tests show that at high filling amount, the Hexagonal Mg(OH)2 particles are distributed uniformly in the PP matrix.The flexural properties of the blends were improved, but the tensile test results and notched impact strength decreased significantly.Mg(OH)2/PP/GNPs ternary blend system was prepared, and its thermal conductivity, electrical conductivity, flame retardancy and mechanical properties were characterized, and its microstructure was observed by SEM.瀹為獙緇撴灉琛ㄦ槑,浠ュ皯閲廏NPs浠ｆ浛Mg(OH)2鍚，

本文編號：1712595