Polyamide 6‐wheat straw composites: Degradation kinetics

Abstract

Degradation kinetics of ground wheat straw (WS), polyamide 6, and a WS‐polyamide 6 composites obtained from extrusion were investigated. 15 wt% of ground WS was melt blended with other additives naming; lithium chloride salt (LiCl) and N‐butylbenzenesulfonamide plasticizer (N‐BBSA) as matrix treatments. The additives were added to reduce the melting point of polyamide 6 and ease of composite processing (reduction in processing temperature and time). Two commonly used non‐isothermal kinetic models were used to investigate the degradation kinetics of WS and the composite. Thermal gravimetric analysis was utilized to measure the thermal stability and degradation kinetics of different composite formulation. The activation energy of WS was identified by iso‐conversional Friedman kinetic method. Through this method, WS activation energy was found to be around 141.4 kJ/mol. Composite kinetic studies were based on the Coats and Redfern procedure. It was concluded that the composite activation energy was correlated to the residual weight percentage of the composite at the maximum thermal degradation temperature. The onset of degradation of WS was dictated by the thermal stability of its lignin content and was found to be around 188°C. WS, however, did not go through a major degradation up to 245°C at which drastic decomposition starts. This temperature range overlaps with processing temperature of Polyamide 6 and required matrix/WS treatments. Addition of salt and plasticizer individually or with each other at any level decreased the onset of degradation temperature. Addition of plasticizer at 4 wt% level, however, shifted the degradation peak to higher temperature representing a more thermally stable composite. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Preparation and Properties of a Novel Microcrystalline Cellulose-Filled Composites Based on Polyamide 6/High-Density Polyethylene

“…Reducing the melting point of polyamides is an effective method, and an increase in the number of papers indicates that small amounts of lithium chloride (LiCl) could decrease the melting point of PA6; then PA6 and wheat straws were blended together to prepare PA6/wheat straw composites. The results indicated that LiCl increased the tensile and flexural modulus, but decreased the impact strength, the tensile strength, and the flexural strength [ 16 , 17 , 18 ].…”

Optimization of wheat‐straw‐extracted cellulose via response surface methodology and mechanical properties of its poly(lactide)‐based biocomposites

“…The increment in degradation and decomposition temperature may be attributed to the removal of lignin and hemicellulose. [24,32] Figure 1D shows the surface morphology of extracted cellulose from wheat straw.…”

Evaluation of degradation of furanic polyamides synthesized with different solvents

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