Linear and non-linear viscoelastic properties of ethylene vinyl acetate/nano-crystalline cellulose composites
Linear and non-linear viscoelastic properties of ethylene vinyl acetate/nano-crystalline cellulose composites
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DOI：
10.1007/s00397-011-0603-9
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发表时间：
2012-02-01
期刊：
影响因子：
2.3
通讯作者：
Rodrigue, Denis
中科院分区：
文献类型：
--
作者：
Mahi, Hojjat;Rodrigue, Denis
本文报道了乙烯-醋酸乙烯酯共聚物的熔体流变性能，纳米结晶纤维素（NCC）。一套完整的流变测试，包括频率扫描，剪切瞬态，和单轴拉伸进行。频率扫描表明，在低频率下，对于高于5%的NCC浓度，获得伪固体状行为。这种行为与NCC颗粒之间的氢键和颗粒间相互作用产生的颗粒网络有关。对于瞬时剪切测试，所有组合物在达到稳态之前在高剪切速率下呈现应力过冲。结果发现，这种超调的幅度取决于NCC含量和剪切速率。另一方面，达到最大值的时间被认为是高度剪切速率依赖性，但浓度依赖性是相当弱的。对于单轴拉伸流动，随着NCC含量的增加，观察到更高的拉伸粘度。另一方面，应变硬化被发现随着NCC含量的增加而降低。
This paper reports on the melt rheological properties of ethylene vinyl acetate containing between 0 and 10 wt.% of nano-crystalline cellulose (NCC). A complete set of rheological tests including frequency sweeps, shear transients, and uniaxial elongations was performed. Frequency sweeps showed that at low frequencies, a pseudo solid-like behavior was obtained for NCC concentrations higher than 5%. This behavior was related to hydrogen bonding between NCC particles and the creation of particle networks as the result of particle-particle interactions. For transient shear tests, all compositions presented a stress overshoot at high shear rates before reaching a steady state. It was found that the amplitude of this overshoot depends on both NCC content and shear rate. On the other hand, the time to reach the maximum was found to be highly shear rate dependent but concentration dependence was rather weak. For uniaxial extensional flow, higher extensional viscosity was observed with increasing NCC content. On the other hand, strain hardening was found to decrease with increasing NCC content.