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首页> 外文会议>International annual conference of ICT >Moisture influence in polyurethane obtained from reaction of glycidyl azide polymer with toluene diisocyanate
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Moisture influence in polyurethane obtained from reaction of glycidyl azide polymer with toluene diisocyanate

机译：缩水甘油叠氮化物聚合物与甲苯二异氰酸酯反应制得的聚氨酯中的水分影响

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Glycidyl azide polymer (GAP) is an energetic material, whose interest in space area has increased recently. One of the most important GAP applications has been as binder for composite solid rocket propellant. Nonetheless, GAP synthesis yielded a liquid polymer with low molar mass, which has no suitable mechanical properties for use as binder in solid propellant. GAP is a polydiol and its reaction with a diisocyanate is expected to result in a polyurethane chain with higher molar mass and better properties. Polyurethane chains are expected as main reaction product in syntheses involving polydiol and diisocyanate. However, small water content adsorbed in GAP can affects the polyurethane formation due to competitive reactions between hydroxyl groups, present in water and GAP, with diisocyanate group. In the present study GAP was reacted with different toluene diisocyanate (TDI) content: 0.8, 1.0,1.25,1.5,2.0 and 2.5 wt%, in presence of dibutyl tin dilaurate (DBTDL) as a catalyst. Two different synthesis conditions were investigated: in controlled environment with relative air humidity of 50%, called RH-50; and submitting GAP to drying under vacuum before its mixture with diisocyanate, named dry GAP. Water content present in GAP was monitored by Karl Fischer in both synthesis conditions. Glass transition temperature (Tg) of GAP/TDI compounds with different TDI content obtained from two synthesis conditions were compared. Materials obtained from dry GAP synthesis condition showed a progressive increase in Tg value with the increase of TDI content up to 2.5 wt%. GAP/TDI compounds prepared by RH-50 condition presented a light increase in Tg value, which stabilized at TDI 1.5 wt%. The cross-linking in GAP/TDI compounds was also investigated by sol-gel analysis, showing increased fraction of gel in GAP/TDI compounds prepared in dry GAP condition. Both results in dry GAP condition suggest the presence of allophanate bonds in higher TDI contents in this material.
机译：缩水甘油叠氮化物聚合物（GAP）是一种高能材料，近来人们对空间领域的兴趣有所增加。 GAP最重要的应用之一是作为复合固体火箭推进剂的粘结剂。尽管如此，GAP合成仍产生了低摩尔质量的液体聚合物，该聚合物没有适合用作固体推进剂中粘合剂的机械性能。 GAP是一种多元醇，它与二异氰酸酯的反应可望产生具有更高摩尔质量和更好性能的聚氨酯链。在涉及聚二醇和二异氰酸酯的合成中，聚氨酯链有望作为主要反应产物。然而，由于存在于水和GAP中的羟基与二异氰酸酯基之间的竞争性反应，GAP中吸附的少量水会影响聚氨酯的形成。在本研究中，在二月桂酸二丁基锡（DBTDL）作为催化剂的情况下，GAP与不同含量的甲苯二异氰酸酯（TDI）：0.8、1.0、1.25、1.5、2.0和2.5 wt％反应。研究了两种不同的合成条件：在相对空气湿度为50％的受控环境中，称为RH-50;在相对湿度为50％的环境中。并在其与二异氰酸酯的混合物（称为干GAP）混合之前，使其在真空下干燥。在两种合成条件下，卡尔·菲舍尔（Karl Fischer）监测GAP中的水分含量。比较了从两种合成条件获得的具有不同TDI含量的GAP / TDI化合物的玻璃化转变温度（Tg）。从干GAP合成条件获得的材料显示出Tg值逐渐增加，TDI含量增加至2.5wt％。通过RH-50条件制备的GAP / TDI化合物的Tg值略有增加，稳定在TDI 1.5 wt％处。还通过溶胶-凝胶分析对GAP / TDI化合物中的交联进行了研究，结果表明在干燥的GAP条件下制备的GAP / TDI化合物中的凝胶分数增加。在干燥的GAP条件下的两个结果均表明该材料中较高的TDI含量中存在脲基甲酸酯键。

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