Aerospace composite cured by quickstep and autoclave processing techniques: Evaluation and comparison of reaction progress
Aerospace composite cured by quickstep and autoclave processing techniques: Evaluation and comparison of reaction progress
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DOI：
10.1016/j.ast.2017.02.014
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发表时间：
2017-06-01
影响因子：
5.6
通讯作者：
Day, Richard J.
中科院分区：
文献类型：
--
作者：
Khan, Laraib A.;Kausar, Ayesha;Day, Richard J.
Quickstep是一种较新的航空复合材料加工技术。热固性树脂（热固性树脂）通常通过高压釜方法设计，其要求2-3 K min（-1）的低升温速率固化。然而，通过Quickstep处理，已经实现了高达15 K min（-1）的斜坡速率。该技术允许改变树脂体系的化学流变性，从而影响反应进程。本文采用傅里叶变换红外光谱（FTIR）、差示扫描量热法（DSC）和动态力学热分析（DMTA）对977-2A环氧树脂和碳纤维增强复合材料的固化过程进行了监测。通过比较Quickstep法和热压罐法，首次考察了977-2A环氧树脂/碳纤维体系的固化反应过程。DSC分析结果表明，Quickstep工艺的反应进程与热压罐固化相当。此外，DMTA的Quickstep固化的样品显示增加的玻璃化转变温度（Tg），由于在更大的保持时间（上限固化温度）增加的交联密度。FTIR用于监测代表性官能团的转化与所应用的Quickstep和高压釜固化步骤。结构分析表明，977-2A树脂的Quickstep固化路径与高压釜固化不同;但最终交联结构与高压釜固化样品相似。(C)2017年Elsevier Masson SAS。All rights reserved.
Quickstep is relatively a new technique for aerospace composite processing. Thermoset resins (prepregs) have been frequently designed by autoclave method requiring low ramp rate curing of 2-3 K min(-1). However, ramp rate up to 15 K min(-1) has been achieved via Quickstep processing. This technique allows alteration in chemo-rheology of resin system and so influences the reaction progress. In this attempt, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA) were used to monitor the cure progress of 977-2A epoxy resin and carbon fiber reinforced composite. The curing reaction progress of 977-2A epoxy/carbon fiber was considered for the first time by comparing Quickstep processing and autoclave method. According to DSC results, the reaction progress in Quickstep technique was comparable to that of autoclave curing. Moreover, DMTA of Quickstep cured samples showed increase in glass transition temperature (Tg) due to increased cross-linking density at greater hold time (upper cure temperature). FTIR was used to monitor the conversion of representative functional groups versus applied Quickstep and autoclave curing steps. The structural analysis depicted that the Quickstep curing path for 977-2A resin was different than the autoclave curing; however the final cross-linked structure was similar to that of autoclave cured samples. (C) 2017 Elsevier Masson SAS. All rights reserved.