Characterization of mechanical and morphological properties of cellulose reinforced polyamide 6 composites

Abstract

The utilization of cellulose in reinforcing engineering thermoplastics through melt compounding processes is an argumentative topic in the natural fiber research community. Three different cellulosic materials were used to reinforce polyamide 6 (PA6) at three loading levels (2.5, 5 and 10 % by weight): (1) microcrystalline cellulose, (2) spray-dried cellulose nanofibrils (CNFs) and (3) spray-dried cellulose nanocrystals (CNCs). The particle size, morphology, and thermostability of cellulose were determined using laser diffraction, scanning electron microscopy (SEM), and thermogravimetric analysis. Compounding of cellulose with PA6 was conducted using a batch mixer at 232°C and testing samples were produced using an injection molder at 270°C. Slight mass loss of cellulose was observed at 232°C while serious thermal degradation occurred at 270°C. No serious thermal degradation of cellulose was observed in the composites because the cellulose materials were exposed to injection molding processing temperatures for a short time period. The mechanical testing results indicated that tensile modulus and strength of the composites were improved by adding cellulose while cellulose had negligible effect on the flexural properties. Impact strength decreased significantly by adding cellulose because of the poor distribution of cellulose particles throughout the matrix using the batch mixing process. Optimized mixing with improved distribution of cellulose are necessary to explore the potential reinforcing effect of cellulose, especially CNF and CNC in PA6. The SEM micrographs showed that there were no agglomerations among the cellulose particles, indicating that spray-dried cellulose materials could be suitable reinforcements in polymer-based composites.

Sustainable and lightweight biopolyamide hybrid composites for greener auto parts

“…[9][10][11][12] Carbon fibre is a synthetic fibre extensively used as a reinforcing agent in aerospace and automotive industries due to its low weight and excellent mechanical properties, including high stiffness and tensile strength and great chemical and thermal resistance. [25][26][27][28][29][30][31][32][33][34][35][36] However, use of these polymers as matrices for cellulosic fibres is challenging as their processing temperatures are above the degradation temperature of the cellulosic fibres. Many studies have reported that hybrid composites composed of natural and synthetic fibres can improve the mechanical and thermal properties of the composites by having the benefits of both fibre types while reducing the costs.…”

“…[13][14][15][16][17][18] However, carbon fibre is non-renewable and energy intensive in its manufacture, and quite expensive compared to natural fibres. [25][26][27][28][29][30][31][32][33][34][35][36] Biopolyamides have relatively low melting temperature and are another suitable alternative to develop cellulosic fibre-reinforced composites with high-performance characteristics. [19][20][21][22][23] Polyamides are one of the most widely used engineering polymer matrices in the automotive industry.…”

Interfacial modification mechanism of nanocellulose as a compatibilizer for immiscible binary poly(vinyl alcohol)/poly(ethylene oxide) blends

“…We also concluded from the temperature corresponding to the first and the second peak of DTG curves ( T max ) in Table that the thermal stability of the polymer blends with CNCs was better than that with CNFs at the same content because of the immiscible interfacial modification. The CNC nanocomposites were assumed to show a much lower temperature at which the maximum mass loss rate occurred due to the sulfate groups from the CNCs during the manufacturing process . The influence of the miscible interface may have been dominant and should be placed ahead of other factors such as reinforcement.…”

Impact of lithium chloride on the performance of wood fiber reinforced polyamide 6/high‐density polyethylene blend composites

“…In order to improve the thermal stabilization of the natural fibers, there are some ways developed for the modification, for instance, sodium hydroxide solution treatment, thermal treatment, and plasma treatment . In addition, cellulose‐based materials with favorable heat resistance were also incorporated, such as microcrystalline cellulose, cellulose nanofibrils (CNFs), and cellulose nanocrystals . According to the previous reports, depressing the melting temperature of PA6 is another promising method.…”

“…[14][15][16] In addition, cellulose-based materials with favorable heat resistance were also incorporated, such as microcrystalline cellulose, cellulose nanofibrils (CNFs), and cellulose nanocrystals. [17][18][19][20] According to the previous reports, depressing the melting temperature of PA6 is another promising method. PA6/wheat straw composites was prepared via incorporating lithium chloride (LiCl).…”