No abstract

Melt rheology and crystallization behavior of polyamide 6 (PA 6) and microcrystalline cellulose (MCC) composites were systematically studied in this research. The incorporation of MCC into the PA 6 matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), and shear viscosities than those of neat PA 6, especially at low frequencies. The orientation of rigid molecular chains in the composites introduced by the addition of MCC induced a strong shear thinning behavior with an increase in MCC loading. The non‐isothermal crystallization kinetics of PA 6 and MCC composites were investigated by differential scanning calorimetry. The Avrami and Tobin model were applied to describe the process of non‐isothermal crystallization and to determine the crystallization parameters of the composites. Analysis of the crystallization kinetics indicated that the Avrami (na) and Tobin exponent (nt) was altered by the MCC. It was also found that the Avrami and Tobin equations fit the empirical data well. POLYM. ENG. SCI., 54:739–746, 2014. © 2013 Society of Plastics Engineers

Hexagonal boron nitride nanosheets (BNNSs) are promising two-dimensional materials to boost the mechanical, thermal, electrical, and optical properties of polymer nanocomposites. Yet, BNNS-polymer composites face many challenges to meet the desired properties owing to agglomeration of BNNSs, incompatibility, and weak interactions of BNNSs with the host polymers. This work systematically reviews the fundamental parameters that control the molecular interactions of BNNSs with polymer matrices. The surface modification of BNNSs, as well as size, dispersion, and alignment of these nanosheets have a profound effect on polymer chain dynamics, mass barrier properties, and stress-transfer efficiency of the nanocomposites.

No abstract

In this study, engineering thermoplastic composites were prepared from natural fiber blend-filled nylon 6. Natural fiber blend from a mixture of kenaf, flax, and hemp fibers were added to nylon 6 using melt mixing to produce compounded pellets. The natural fibers/ nylon 6 composites with varying concentrations of natural fibers (from 5 to 20 wt%) were prepared by injection molding. The tensile and flexural properties of the nylon 6 composites were increased significantly with the addition of the natural fiber blend. The maximum strength and modulus of elasticity for the nylon 6 composites were achieved at a natural fiber blend weight fraction of 20%. The Izod impact strength of composites decreased with the incorporation of natural fibers without any surface treatments and coupling agent. The melt flow index (MFI) also decreased with increasing natural fiber blend loading. The results of tensile and flexural modulus of elasticity (FMOE) are in accordance with the rheological data from the MFI measurements. The increase in the tensile and flexural properties indicated that efficient bonding occurred between the natural fibers and nylon 6. No fiber pullout was observed during the scanning electron microscopic analysis of the fracture surfaces. The higher mechanical results with lower density demonstrate that a natural fiber blend can be used as a sufficient reinforcing material for low-cost, eco-friendly composites in the automotive industry and in other applications such as the building and construction industries, packaging, consumer products, etc. POLYM. COMPOS., 34:544-553, 2013. ª

No abstract

No abstract

No abstract