A review on MWCNTS: the effect of its addition on the polymer matrix

In recent years, it has been realized that nanocomposite materials are candidates for many applications in all fields due to their unique properties. This review aims to study the possibility of modifying some properties of polymers by adding carbon nanotubes to improve their properties by taking advantage of the large surface area of MWCNTs to volume ratio. For this purpose, multi-walled carbon nanotubes were used at different ratios and by different mixing methods. Then the effect of this addition was monitored by the procedure of some mechanical, electrical and thermal measurements of the resulting nanocomposite materials. The results of the tests showed that the quality of the filling depends on the way it is distributed within the polymer matrix, where the homogeneous dispersion of MWCNTs will reflect on the properties of the nanocomposite material thus benefit from the special properties of it. Also, the results showed that the addition of MWCNTs at low ratios achieved uniform distribution and dispersion, so improved the properties of the materials such as tensile strength, elongation at break and young's modulus. The ratio of 0.5 wt % of MWCNTs represented an average value for adding MWCNTs to various types of polymers. These composite nanomaterials can replace other industrial materials in many applications

Effect of Reprocessing on the Crystallization of Different Polyesters

The changes in crystallization characteristics of four polyesters were investigated during multiple processing. Two of these were petroleum-based materials: poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT), and two were bio-based materials: poly (lactic acid) (PLA) and poly (butylene succinate) (PBS). We found that during non-isothermal crystallization the different type of polyesters shown different behaviour: the PET and PLA materials were more sensitive to the cooling rate than the PBT and PBS. Interestingly, at low cooling rates, the number of reprocessing steps had no significant effect on the crystallinity of PBT and PBS, but reduced it for PET, but increased it for PBT