本文關(guān)鍵詞：疊氮型熱塑性聚氨酯彈性體的制備及性能研究　出處：《南京理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： GAP PTMG 機(jī)械力學(xué)性能 動態(tài)力學(xué)性能 PBT 支化

【摘要】：疊氮聚醚復(fù)合固體推進(jìn)劑具有高能、高燃速、低特征信號等優(yōu)點(diǎn),是目前推進(jìn)劑發(fā)展的一個重要方向。其中疊氮縮水甘油醚(GAP)和疊氮類聚醚3,3-疊氮甲基環(huán)氧丁烷-四氫呋喃(PBT)由于能夠提供較高的能量,并且具有較低的玻璃化轉(zhuǎn)變溫度等因而被廣泛用于粘合劑的制備和研究。然而由于這類聚醚分子側(cè)鏈含有剛性疊氮基團(tuán),其單體相對分子質(zhì)量較大,使得分子柔順性變差,是造成疊氮聚醚推進(jìn)劑力學(xué)性能不佳的原因之一。本文一方面通過引入柔順型良好的結(jié)晶軟段與GAP形成協(xié)同作用,改善彈性體的力學(xué)性能,另外一方面通過對PBT進(jìn)行支化改性,改善其工藝性能和力學(xué)性能。為了探究軟段的引入對GAP基熱塑性聚氨酯彈性體的影響,采用熔融預(yù)聚法制備了一系列嵌段共聚物聚氨酯彈性體試樣,通過單因素實(shí)驗(yàn)確定最優(yōu)化的工藝條件為:選擇聚四氫呋喃(PTMG)作為第二軟段,4,4-二苯基甲烷二異氰酸酯(MDI)作為固化劑,一縮二乙二醇(DEG)作為擴(kuò)鏈劑,固化參數(shù)R值(NCO/OH)為1.2,DEG含量為 20%。對GAP-PTMG熱塑性彈性體不同軟段組分(GAP/PTMG分別為5/5,6/4,7/3,8/2,9/1)進(jìn)行進(jìn)一步的探究,其拉伸性能和動態(tài)力學(xué)性能實(shí)驗(yàn)結(jié)果表明,當(dāng)GAP含量為50%時,其拉伸強(qiáng)度達(dá)到18.97MPa,延伸率為770%,Tg為-18.56℃,即具有良好的力學(xué)性能;其蠕變性能和應(yīng)力松弛實(shí)驗(yàn)結(jié)果表明GAP-PTMG熱塑性彈性體具有一定的粘彈塑性特性,并且隨著GAP含量增加,蠕變應(yīng)變量增加,更易產(chǎn)生應(yīng)力松弛現(xiàn)象;通過熱力學(xué)分析表明其具有良好的熱穩(wěn)定性。為改善PBT的工藝性能,本文以PBT為起始聚醚,三官能度的支化單元為引發(fā)劑,通過親核加成反應(yīng)合成一種具有支化結(jié)構(gòu)的PBT(B-PBT),然后通過一步法制備得到B-PBT熱塑性彈性體。通過結(jié)構(gòu)分析表明B-PBT為具有支化結(jié)構(gòu)的疊氮型聚醚;通過粘度測試表明B-PBT的粘度明顯低于PBT;通過力學(xué)性能測試表明制備的B-PBT熱塑性彈性體拉伸強(qiáng)度達(dá)到5.29 MPa,延伸率達(dá)到516%。
[Abstract]:Azide polyether composite solid propellant has the advantages of high energy, high burning rate, low characteristic signal and so on. It is an important direction of propellant development at present, including azide glycidyl ether (GAPP) and azido polyether 3 (azido polyether 3). 3-azidomethyl epoxy-butane-tetrahydrofuran (PBT) can provide higher energy. Because of its low glass transition temperature and so on, it is widely used in the preparation and study of adhesives. However, due to the existence of rigid azide groups in the side chain of this kind of polyether, the relative molecular weight of the monomers is larger. One of the reasons for the poor mechanical properties of azido polyether propellants is the deterioration of molecular flexibility. On the one hand, the flexible crystalline soft segment is introduced to form a synergistic effect with GAP. On the other hand, the mechanical properties and technological properties of PBT were improved by branching modification. In order to explore the effect of soft segment on GAP based thermoplastic polyurethane elastomer. A series of block copolymer polyurethane elastomer samples were prepared by melt prepolymerization. The optimum technological conditions were determined by single factor experiment: PTMGG was selected as the second soft segment. 4-diphenylmethane diisocyanate (MDI) was used as curing agent and diethylene glycol (DEG) as chain extender. The curing parameter R value of NCO / OH was 1.2. The DEG content is 20. For GAP-PTMG thermoplastic elastomers, the GAP-PTMG / PTMG is 5 / 5 / 6 / 4 / 4 / 7 / 3 / 8 / 2, respectively. 9 / 1). The results of tensile and dynamic mechanical properties experiments show that when the content of GAP is 50, the tensile strength is 18.97 MPA and the elongation is 770%. TG is -18.56 鈩，

本文編號：1372526