Evaluation of crystallinity variation and phase dispersion in polymer blends and nanocomposites by Raman mapping

Quantitative analysis of s-PB/SBR blend dispersion morphology using computer image processing-assisted Raman spectroscopic techniques

In the materials industry, it is significant to clarify the correlation between the material dispersion morphology and the mechanical properties of rubber blends, which are comprehensively employed and are always in the spotlight. However, there are no generalized automatic visual characterization methods for dispersion morphology at present. In this paper, we wish to introduce a novel computer image processing-assisted approach for quantitative evaluation based on Raman mapping images, in which inhomogeneity factor K_c was defined to characterize the homogeneity of rubber blends. This numerical processing technique will provide a more objective standard for the quality control of relevant materials and products. It may be of profound impact on the information and automation of material engineering and is a key technique for automatic production and quality inspection of the related materials in industry.

Manufacturing and Characterization of Toughened Poly(lactic acid) (PLA) Formulations by Ternary Blends with Biopolyesters

Ternary blends with a constant poly(lactic acid) (PLA) content (60 wt %) and varying amounts of poly(3-hydroxybutyrate) (PHB) and poly(ε-caprolactone) (PCL) were manufactured by one step melt blending process followed by injection moulding, with the main aim of improving the low intrinsic toughness of PLA. Mechanical properties were obtained from tensile and Charpy impact tests. The miscibility and morphology of the system was studied by thermal analysis and field emission scanning electron microscopy (FESEM). The obtained results showed a clear phase separation, thus indicating poor miscibility between these three biopolyesters, i.e., PLA, the continuous component with dispersed PHB and PCL domains in the form of different sphere size. Nevertheless, the high fragility of PLA was remarkably reduced, as detected by the Charpy impact test. In accordance with the decrease in brittleness, a remarkable increase in elongation at break is achieved, with increasing PCL load due to its flexibility; in addition, increasing PCL load provides thermal stability at high temperatures. Thus, tailored materials can be manufactured by melt blending PLA, PHB, and PCL in different percentages to offer a wide range of biodegradable polymer blends.