TG/FTIR/MS study on the influence of nanoparticles content upon the thermal decomposition of starch/poly(vinyl alcohol) montmorillonite nanocomposites

Green Nanocomposites Based on Thermoplastic Starch: A Review

The development of bio-based materials has been a consequence of the environmental awareness generated over time. The versatility of native starch is a promising starting point for manufacturing environmentally friendly materials. This work aims to compile information on the advancements in research on thermoplastic starch (TPS) nanocomposites after the addition of mainly these four nanofillers: natural montmorillonite (MMT), organically modified montmorillonite (O-MMT), cellulose nanocrystals (CNC), and cellulose nanofibers (CNF). The analyzed properties of nanocomposites were mechanical, barrier, optical, and degradability. The most important results were that as the nanofiller increases, the TPS modulus and strength increase; however, the elongation decreases. Furthermore, the barrier properties indicate that that the incorporation of nanofillers confers superior hydrophobicity. However, the optical properties (transparency and luminosity) are mostly reduced, and the color variation is more evident with the addition of these fillers. The biodegradability rate increases with these nanocompounds, as demonstrated by the study of the method of burial in the soil. The results of this compilation show that the compatibility, proper dispersion, and distribution of nanofiller through the TPS matrix are critical factors in overcoming the limitations of starch when extending the applications of these biomaterials. TPS nanocomposites are materials with great potential for improvement. Exploring new sources of starch and natural nano-reinforcement could lead to a genuinely eco-friendly material that can replace traditional polymers in applications such as packaging.

Improved Thermal and Fire Retardant Behavior of Polyvinyl Alcohol Matrix Using Nanocomposites

This report discusses in detail about the Fire retardant (FR) characteristics of polyvinyl alcohol (PVA) matrix fabricated by impregnating zinc borate nanoparticles (ZB Nps) as FR with trace amounts of copper chloride/aluminum chloride by solvent casting method. ZB Nps prepared by co-precipitation method are characterized using XRD, FTIR, SEM, TEM, etc. XRD pattern revealed the crystal geometry of ZB Nps and SEM and TEM micrographs depict a rod-like structure with 300–400[Formula: see text]nm size. Appropriate amount of ZB Nps and transition metal salts are mixed with PVA in aqueous medium and thin film samples are obtained by solvent casting method. The vibrational spectra, thermal stability and flammability of the polymeric composites are characterized using FTIR, TG/DTA and Flammability tester, respectively. FTIR spectra confirm the existence of ZB Nps in the prepared polymer composites. TG/DTA studies revealed higher degradation temperature and thermal stability of polymer composite over pure PVA. The limiting oxygen index (LOI) test presented a convincing account about the improved FR nature of obtained polymer nano composite with a significant LOI of 56% compared to virgin polymer which have LOI of 19.6%.

The modification and characterization of thermal-treated sericite by fluorosilicate

In this article, the thermal-treated sericite was modified by both fluorosilicate and the combination of fluorosilicate and nitric acid in order to reduce its layer charge and gain cation exchange capabilities for the preparation of sericite/polymer nanocomposites. After several orthogonal experiments and single factor experiments, the optimal experimental conditions were set up and we found that the combination of nitric acid and fluorosilicate is much more effective than fluorosilicate alone. Chemical composition analysis showed Al³⁺ was dissolved out from sericite and the dissolving amount is 65 mg/g under optimal experimental conditions. Combining the NMR test, it is considered that the Si/Al ratio in the tetrasheet of the modified product increased from 3.48 to 10. The layer charge reduced and the CEC value increased after fluorosilicate modification, which means the modified sericite is a promising matrix for clay-polymer nanocomposites.

Reaction mechanism of thermally-induced electric conduction of poly(vinyl alcohol)–silver nitrate hybrid films

The combination of metal nanoparticles and polymers endows their hybrid composites with a number of unique features and opens a new way to fabricate novel functional materials.