Nucleating Effect of Carbon Nanoparticles and Their Influence on the Thermal and Chemical Stability of Polypropylene

Abstract

The effect of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) on the thermal and chemical stability of polypropylene (PP) when subjected to oxidation in a strong acid medium was studied. The effect of CNFs and CNTs on the crystalline morphology and the melting and crystallization temperatures was also studied. The thermal stability increased markedly; the decomposition temperature, for example, increased from 293∘C for pure PP to 312 and 320∘C for PP with CNFs and CNTs, respectively. The crystallization temperature increased perceptibly with the addition of CNTs or CNFs, from 107∘C for pure PP to 112 and 114∘C for PP with CNFs and CNTs, respectively. The oxidative degradation with nitric acid produced a reduction in molecular weight; however, this negative effect was less pronounced in the PP compositions with carbon nanoparticles. After 8 hours in nitric acid, this reduction was from 141,000 to 68,000 (for pure PP), to 75,000 (for PP-CNFs), and 79,500 (for PP-CNTs). X-ray diffraction showed that the alpha type crystallinity remains, irrespective of the nucleating agent. Finally, the intensity ratio between the (040) (at 16.7∘) and the (110) (at 13.9∘) reflections increased, which was taken as an indication of an increasing nucleating efficiency.

Surface Modification of Carbon Nanofibers and Graphene Platelets Mixtures by Plasma Polymerization of Propylene

“…It is well known that the plasma polymerization promotes crosslinked structures, due to the multiple reactive species that are generated during the process. This is reflected in the decomposition temperature obtained by TGA, higher than the decomposition temperature of polypropylene (300 ∘ C) [42][43][44].…”

Mechanical and Rheological Properties of Isotactic Polypropylene/Bacterial Cellulose Composites

“…In recent years, many studies are concentrated various kinds of composites with excellent mechanical properties by added different kinds of fillers (fibers, particles). [2][3][4][5] Isotactic polypropylene (iPP) has a lot of useful properties such as low density, electrical resistance, and chemical resistance. iPP has been particularly studied and widely used in automotive, packaging materials and other industries.…”

In-situ one-step synthesis of carbon-encapsulated naked magnetic metal nanoparticles conducted without additional reductants and agents

“…However, the core-shell nanostructures manufactured from silica and polymers are not perfect due to the (i) dissolution of silica coatings at strong basic conditions and (ii) low thermal stability of organic polymers. In contrast to these materials, C has many advantages, such as high stability under various physical and chemical conditions, good biocompatibility161718, high electrical conductivity, and relatively low manufacturing costs. Moreover, C surface can be modified by various functional groups (including OH and COOH ones), which enhance its dispersibility in polar solutions19 and produce ternary hybrid structures20.…”