發(fā)布時間：2018-08-09 17:10

【摘要】：微孔發(fā)泡聚合物材料作為結(jié)構(gòu)材料使用時,對強度和韌性要求較高,目前主要添加纖維增強相來提高其強度和韌性,國內(nèi)外學(xué)者從界面行為和改性機理進行了大量的研究;可是對于發(fā)泡增強復(fù)合材料,發(fā)泡質(zhì)量的調(diào)控對強度和韌性是需要解決的關(guān)鍵科學(xué)問題,一方面通過改善發(fā)泡質(zhì)量有效抑制氣相往增強相表面聚集,保持增強相本身的增強增韌效應(yīng);另一方面通過改善發(fā)泡質(zhì)量實現(xiàn)細(xì)小而均勻的泡孔有利于提升其強度和韌性。因此,對于聚合物發(fā)泡增強復(fù)合材料來說,如何調(diào)控發(fā)泡質(zhì)量實現(xiàn)增強相本身的增強增韌以及獲得細(xì)小而均勻的泡孔尺寸對結(jié)構(gòu)發(fā)泡材料制品的工業(yè)化應(yīng)用具有非常重要的意義。本文選取三種典型纖維(AF、GF、CF)制備發(fā)泡PP/纖維復(fù)合材料,研究了纖維特性和纖維表面改性對微發(fā)泡聚丙烯復(fù)合材料發(fā)泡行為的影響機理。同時分析了加工工藝、復(fù)合發(fā)泡劑對發(fā)泡PP復(fù)合材料泡孔結(jié)構(gòu)的調(diào)控作用機理。論文研究取得了以下主要成果:1.纖維可以有效改善微發(fā)泡PP材料的泡孔結(jié)構(gòu),改善效果CFGFAF,PP/CF發(fā)泡材料的泡孔直徑為27.689μm,泡孔密度為8.67×106cells/cm3。添加未改性GF的發(fā)泡材料,其泡孔直徑為29.67μm,泡孔密度為3.45×107cells/cm3,GF經(jīng)表面處理后發(fā)泡材料的泡孔直徑增大至42.56μm,泡孔密度減小至8.39×106cells/cm3,同時泡孔與GF分離的類型Ⅰ的比重增加,有效抑制了氣相向GF表面聚集,提高了纖維的增強增韌效果。2.模溫的升高,加劇了泡孔合并,從而導(dǎo)致泡孔直徑增加,泡孔密度減少,同時與純PP發(fā)泡材料相比,PP/GF發(fā)泡材料的“過發(fā)泡狀態(tài)”延遲出現(xiàn)。3.釋壓速率越大,單位時間內(nèi)的壓力降越大,成核速率越高。隨著釋壓速率的增大,泡孔直徑從26.678μm減小至17.998μm,泡孔密度從1.41×107cell/cm3增大至4.66×107cell/cm3。4.濕法研磨法不適于制備AC/硅藻土復(fù)合發(fā)泡劑,采用溶液法成功制備了硅藻土/OBSH復(fù)合發(fā)泡劑,使OBSH發(fā)泡劑實現(xiàn)分子水平的分散,負(fù)載效果較好,負(fù)載量高。與OBSH發(fā)泡劑相比,硅藻土/OBSH復(fù)合發(fā)泡劑使得泡孔直徑從275.47μm降低至176.45μm,泡孔密度從3.32×103cells/cm3增加至5.73×104cells/cm3。
[Abstract]:The strength and toughness of microcellular foamed polymer materials are very high when they are used as structural materials. At present, fiber reinforced phase is mainly added to improve their strength and toughness. However, for foaming reinforced composites, the control of foaming quality on strength and toughness is a key scientific problem to be solved. On the one hand, by improving the quality of foaming, the gas phase aggregation to the surface of the enhanced phase can be effectively inhibited. On the other hand, to improve the foaming quality, to achieve fine and uniform foam pores is beneficial to enhance its strength and toughness. So, for polymer foamed composites, How to control the foaming quality to realize the strengthening and toughening of the reinforcing phase and to obtain the fine and uniform size of the foam pore is of great significance for the industrial application of the structural foamed materials. In this paper, three kinds of typical fiber (AFG / CF) were selected to prepare foamed PP/ fiber composites. The effects of fiber properties and fiber surface modification on the foaming behavior of microfoamed polypropylene composites were studied. At the same time, the control mechanism of processing technology and compound foaming agent on foam structure of PP composite was analyzed. The main achievements of this paper are as follows: 1. 1. The fiber can effectively improve the cellular structure of the microfoamed PP material. The effect is that the diameter of the foamed PP / PP / CF foamed material is 27.689 渭 m and the cell density is 8.67 脳 10 ~ (6) cells / cm ~ (-3). The foam material with unmodified GF has a diameter of 29.67 渭 m, a density of 3.45 脳 10 ~ 7 cells / cm ~ (-3) GF. After surface treatment, the cell diameter of foamed material increases to 42.56 渭 m, the cell density decreases to 8.39 脳 10 ~ (6) cells / cm ~ (-3), and the proportion of foam pore and type 鈪，

本文編號：2174752