Cellulose nanofibers hold much promise for enhancing the mechanical properties of composites owing to their uniquely high stiffness and strength. One major issue limiting this performance however is the dispersion and mixing of cellulose nanofibers within thermoplastic resins. A combination of Raman imaging and chemical analysis has been used to quantify the distribution and mixing of cellulose nanocrystals (CNCs) in a polyethylene-matrix composite. Large area spectral imaging provides information about the effect of a compatibilizer – namely poly(ethylene oxide) (PEO) and maleated polyethylene (MAPE) – on the distribution of CNCs in the thermoplastic matrix. High-resolution images enable quantification of the degree of mixing between the CNCs and HDPE. Lower resolution images, but with greater spatial spread, allow quantification of the distribution of the CNCs. It is shown that the CNCs tend to agglomerate, with little increase in distribution even with the use of the compatibilizer. A shift in the position of characteristic Raman bands indicates the formation of hydrogen bonding between the PEO compatibilizer and the CNCs, which in turn is thought to affect the distribution of aggregates of the reinforcing phase.

中文翻译：

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使用拉曼化学成像定量分析热塑性复合材料中纤维素纳米晶体的分布和混合†

纤维素纳米纤维因其独特的高刚度和强度而在增强复合材料的机械性能方面具有很大的前景。然而，限制这种性能的一个主要问题是纤维素纳米纤维在热塑性树脂中的分散和混合。拉曼成像和化学分析相结合已用于量化聚乙烯基复合材料中纤维素纳米晶体 (CNC) 的分布和混合。大面积光谱成像提供了有关增容剂（即聚环氧乙烷 (PEO) 和马来酸聚乙烯 (MAPE)）对热塑性基体中 CNCs 分布影响的信息。高分辨率图像可以量化 CNC 和 HDPE 之间的混合程度。较低分辨率的图像，但具有更大的空间分布，允许量化 CNC 的分布。结果表明，即使使用增容剂，CNCs 也容易结块，分布几乎没有增加。特征拉曼谱带位置的变化表明 PEO 增容剂和 CNCs 之间形成了氢键，这反过来被认为会影响增强相聚集体的分布。