發(fā)布時(shí)間：2018-03-13 14:39

  本文選題：稻草　切入點(diǎn)：PEG　出處：《江南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：稻草—廢棄的資源,是我國(guó)最重要的一種可再生生物質(zhì)資源之一。它可以直接燃燒用作燃料,但是這樣不但造成浪費(fèi),而且還會(huì)嚴(yán)重造成大氣污染,現(xiàn)在已經(jīng)可以通過(guò)生物質(zhì)能轉(zhuǎn)換技術(shù)來(lái)生產(chǎn)各種清潔燃料。同時(shí)它還可以作為可再生天然高分子的載體,也是比較理想的材料來(lái)源,由其制成的改性復(fù)合材料可以成為傳統(tǒng)有機(jī)材料的替代品。本課題設(shè)想以聚乙二醇(PEG)為改性試劑將纖維素改性方法應(yīng)用于稻草改性中,利用高活性的4,4-二苯甲烷二異氰酸酯(MDI)作為一個(gè)橋接化合物,采用超聲-微波共輻射技術(shù),通過(guò)化學(xué)偶聯(lián)反應(yīng)在稻草纖維上引入一定數(shù)量的聚氧乙烯基柔性鏈段。這可以削弱稻草纖維大分子間的相互作用,改變稻草的物理、化學(xué)結(jié)構(gòu),從而得到具有熱塑性的稻草改性材料。研究了微波功率、超聲功率、時(shí)間、溫度、以及PEG加入量對(duì)接枝程度的影響。因此獲得了稻草MDI改性的優(yōu)化反應(yīng)條件,也確定了超聲波-微波協(xié)同作用下稻草的PEG接枝共聚改性的最佳條件。Straw-MDI接枝過(guò)程：稻草與PEG質(zhì)量比1：2；微波功率300 W,超聲波功率270 W,反應(yīng)溫度60℃,反應(yīng)時(shí)間60min; Straw-MDI與PEG的接枝過(guò)程：微波功率300 W,超聲功率360 W,溫度60℃,時(shí)間70 min。利用紅外(FT-IR)、核磁(1H-NMR、13C-NMR)、XRD表征了接枝改性前后稻草纖維的物理、化學(xué)結(jié)構(gòu)的變化。熱分析(TGA和DSC)表征結(jié)果表明改性稻草的熱穩(wěn)定性均有所改善,并獲得了預(yù)期的熱塑性。此外在改性稻草的DSC曲線120℃-180℃左右出現(xiàn)一個(gè)寬廣的熔融峰,在180℃以上,接枝稻草共聚物可以在不添加其他增塑劑的情況下熱壓成板。將改性的稻草粉與彈性聚氨酯(TPU)混合,在一定溫度和壓力下可制成高強(qiáng)度和高彈性模量的稻草/TPU復(fù)合材料。
[Abstract]:Straw-waste resource is one of the most important renewable biomass resources in our country. It can be burned directly as fuel, but it not only causes waste, but also causes serious air pollution. It is now possible to produce all kinds of clean fuels through biomass energy conversion technology. At the same time, it can also be used as a carrier of renewable natural polymers and an ideal source of materials. The modified composite can be used as a substitute for traditional organic materials. In this paper, the modified method of cellulose is supposed to be used in the modification of rice straw with polyethylene glycol (PEG) as the modification reagent. The highly active 4-diphenylmethane diisocyanate (MDI) was used as a bridging compound. A certain number of polyoxyethylene flexible segments were introduced into the straw fiber by chemical coupling reaction, which can weaken the interaction between the macromolecules of straw fiber and change the physical and chemical structure of rice straw. The effects of microwave power, ultrasonic power, time, temperature and the amount of PEG on the grafting degree of rice straw were studied. Therefore, the optimum reaction conditions for the modification of straw MDI were obtained. The optimum conditions of PEG graft copolymerization modification of rice straw under the synergistic action of ultrasonic and microwave were also determined. Straw-MDI grafting process was as follows: the mass ratio of straw to PEG was 1: 2, microwave power was 300W, ultrasonic power was 270W, reaction temperature was 60 鈩，

本文編號(hào)：1606821