Viscoelastic properties of polymer surfaces investigated by nanoscale dynamic mechanical analysis
Viscoelastic properties of polymer surfaces investigated by nanoscale dynamic mechanical analysis
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DOI：
10.1063/1.2189156
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发表时间：
2006-03-27
影响因子：
4
通讯作者：
Komvopoulos, K
中科院分区：
文献类型：
--
作者：
Chakravartula, A;Komvopoulos, K
采用纳米动态力学分析(Nano-DMA)研究了10-200 Hz频率范围内的接触力调制作用下聚合物表面的粘弹性。Nano-DMA实验采用名义曲率半径为100 nm的Berkovich金刚石针尖，平均接触力为8-10µN，交变作用力为平均作用力的2%。低密度聚乙烯、高密度聚乙烯和超高相对分子质量聚乙烯的损耗正切值、储能模数和损耗模数随力频率的变化表现出与相对大深度(75-100 nm)明显不同的粘弹性行为。从材料的微观结构特征和聚合物表面分子链的运动性两个方面解释了交变力、频率和压痕深度对不同聚乙烯材料粘弹性能的影响。结果表明，纳米DMA技术是纳米尺度研究聚合物表面粘弹性行为的有效手段。(C)2006年美国物理研究所。
The viscoelastic properties of polymer surfaces were investigated by nanoscale dynamic mechanical analysis (nano-DMA) involving contact force modulation in the frequency range of 10-200 Hz. Nano-DMA experiments were performed with a Berkovich diamond tip of nominal radius of curvature equal to similar to 100 nm under a mean contact force of 8-10 mu N and alternating force equal to 2% of the mean force. Variations in the loss tangent, storage modulus, and loss modulus of low- and high-density polyethylene and ultrahigh molecular weight polyethylene with the force frequency demonstrated significantly different viscoelastic behaviors for shallow depths (< 40 nm) than for relatively large depths (i.e., 75-100 nm). The effects of alternating force frequency and indentation depth on the viscoelastic properties of the different polyethylene materials are interpreted in terms of the microstructure characteristics and the molecular chain mobility at the polymer surfaces. The results show that nano-DMA is an effective technique for nanoscale studies of the viscoelastic behavior of polymer surfaces. (c) 2006 American Institute of Physics.