ABSTRACT
Damping characteristics and viscoelastic behavior of flax/epoxy composites reinforced with carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNT) were investigated in this study. The viscoelastic behavior was studied utilizing dynamic mechanical analysis (DMA), conducted on all the fabricated composite specimens and neat-resin (pure epoxy). The results revealed an improvement in glass transition temperature (Tg) for flax epoxy composites with 0 wt.%, 0.5 wt.%, and 1 wt.% reinforcement of MWCNT when compared to the free-resin. From the obtained graphs, C-factor was estimated, adhesion factor and Cole–Cole plots were drawn. The frequency response function (FRF) plot, obtained from free vibration testing, unveils the natural frequencies at mode-I and mode-II vibration, and their respective damping ratios are estimated by half-power bandwidth method. The damping ratios and the natural frequencies increased with the addition of MWCNT. The flax/epoxy composite reinforced with 1 wt.% of MWCNT was found to prevail over the rest by exposing great vibration damping, viscoelastic and mechanical properties.
摘要
研究了羧基官能化多壁碳纳米管 (COOH-MWCNT) 增强亚麻/环氧复合材料的阻尼特性和粘弹性行为. 利用动态力学分析 (DMA) 对所有制造的复合材料试样和纯树脂 (纯环氧树脂) 进行粘弹性行为研究. 结果表明, 与游离树脂相比, 添加0 wt.%, 0.5 wt.%和1 wt.%MWCNT的亚麻-环氧复合材料的玻璃化转变温度 (Tg) 有所提高. 根据获得的曲线图, 估算了C因子, 绘制了粘附因子和油菜-油菜曲线图. 从自由振动测试中获得的频率响应函数 (FRF) 图揭示了I型和II型振动的固有频率, 并通过半功率带宽法估计了它们各自的阻尼比. 随着MWCNT的加入, 阻尼比和固有频率增加. 发现1%MWCNT增强的亚麻/环氧复合材料具有良好的减振, 粘弹性和力学性能, 优于其他材料.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Research highlights
Influence of nano-additives in the resin aiming to achieve the improved mechanical properties and other primary characteristics has been gaining the demand among the researchers today.
Emphasizing the natural fiber advantages with identified inherent strength properties leads to replace the polymers in use.
Sound absorbing properties and vibration damping properties are often secondary design criteria in composite structures, whereas mechanical performance and weight are primary concerns.
The flax/epoxy composite reinforced with 1 wt.% of MWCNT was found to prevail over the rest by exposing great vibration damping.
Chain mobility was reduced as a result of the enhanced bonding between matrix and fiber generated by the inclusion of MWCNT, lowering the loss modulus.