HTPB基聚胺基甲酸酯機械性能改善之研究

Abstract

HTPB具優越之低溫特性、高彈性能、低黏度及對固體填充料之包容性大， 且極易入器成形，故早期主要用於火箭固體組合推進劑之研究。但因其分 子量低，故機械性質尚不足與極高分子量之固體橡膠匹敵。聚苯乙烯具顯 著的脆性極限，是相對成本較低之熱可塑性材料，且苯乙烯單體呈液狀， 粘度極低可作為HTPB之良溶劑。本研究擬利用PS與HTPB之組合，期能得到 成本低且性能更優越之互穿型網狀結構(IPN)彈性體。而且使得施工方便 、操作簡單及可應用於複合材料之製作。本研究IPN之製法分SIN及SIPN兩 種方式，SIN方法主要以催化劑Dibutyltin dilaurate之濃度來控制兩成 份反應速率為相等；而SIPN方法則是改變兩成份組成之比例，進而探討這 些變數對機械性質之影響由IR分析知兩成份除了各自形成PU及PS外，尚包 括苯乙烯接枝、交聯聚丁二烯；DSC之分析提供了反應機構可資利用之訊 息；SEM之觀察發現PU/PS比率在30/70∼50/50間， PS產生離散之球形構 造，外圍環繞著PU薄層相。經由IPN手法所製成的互穿型交聯網狀彈性體 其機械性質大幅提升，顯著的韌性亦發生在PU/PS比率於30/70∼50/50之 間。 Hydroxy-terminated polybutadiene(HTPB) offers many advantages like good low temperature flexibility、high resilience、low vis- cosity、high solids loading capability，and it is easy to cast into any shape. Therefore,it mainly applies to rocket solid com- posite propellant at early period.HTPB with low molecular weight isn't a match for PB elastomer with high molecular weight.Polys- tyrene(PS) a relatively low cost thermoplastic material, having a prominent limitation in its brittles.Styrene monomer, however， is liquid and very low viscosity and good solvent for HTPB.It is expected to get low cost and Interpenetrating network (IPN) elas- tomer of excellent stress and strain characteristics by the nation of PS with HTPB. In addition, it is convenient to operate and apply to composite materials.Two methods,SIN and SIPN ,were used as manufacturing IPN. SIN method uses of Dibutyltin laurate to make two components (PU/PS) to attain same reaction te.SIPN method changes PU-PScomposition ratio(w/w).The effect of these variables on mechanical properties was studies.From IR trum analysis it is seen that reactions takes place including PS formation and styrene grafting and crosslinking onto HTPB. DSC analysis offers the information of reaction mechanism.The SEM rograph indicates that PS is apparently characteristic of cal shape of the discrete domain encompassed by the thin layers the PU phase. The most prominent toughness can be obtained 30:70 and 50:50 PU:PS blend ratio .