Plastic waste is currently generated at a rate approaching 400 Mt year–1. The amount of plastics accumulating in the environment is growing rapidly, yet our understanding of its persistence is very...

Degradation Rates of Plastics in the Environment

Poly (lactic acid) blends: Processing, properties and applications.

Polylactic acid blends: The future of green, light and tough

Poly(lactic acid) (PLA) is regarded as one of the most promising bio-based and biodegradable polymers, due to its excellent biodegradability, biocompatibility, renewability, high strength, and easy processibility. However, disadvantages such as brittleness and relatively high cost have restricted its applications significantly. Polymer blending provides an economic and efficient way to modify the properties of PLA. Most shortcomings of PLA are theoretically surmountable by blending with abundant polymers with various properties. But, unfortunately, PLA is thermodynamically immiscible with most existing polymers. High-performance PLA-based blends are usually unanticipated by direct blending. In order to obtain PLA-based blends with excellent overall properties, compatibilization is required during polymer blending. Various strategies have been employed or developed to compatibilize PLA blends with different polymers, as reported in recent studies. This article aims to review the development in compatibilization strategies employed in PLA-based blends.

Compatibilization strategies in poly(lactic acid)-based blends

Polylactic acid (PLA) is a thermoplastic derived from renewable resources, which degrades to nontoxic compounds in landfills. With current advances in the field of nanotechnology, development of layered silicate-based PLA nanocomposites successfully created a sustainable material with enhanced physical, thermal and chemical properties, holding the future as an alternative to petroleum-based materials. However, the toughness of PLA in its pristine state and nanocomposites is often insufficient. As such, there has been tremendous effort in developing ways to improve this with incorporation of plasticizers and impact modifiers. In this review, we summarize approaches in toughening of PLA and its nanocomposites.

Toughening of Polylactic Acid Nanocomposites: A Short Review

Melt blending of linear low density polyethylene (LLDPE) and polylactide (PLLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without compatibilizer-grafted low density polyethylene maleic anhydride. The blend compositions were optimized for tensile properties as per ASTM D 882-91. Based on this, LLDPE 80 (80 wt% LLDPE & 20 wt% PLLA) and M-g-L 80/4 (80 wt% LLDPE, 20 wt% PLLA and 4 parts compatibilizer per hundred parts of resin) were found to be an optimum composition. FTIR reveals that the presence of compatibilizer shifts carbonyl peak hence some increase in interaction between LLDPE and PLLA. Morphological characteristics of the fracture surface of with and without compatibilizer blends were examined by scanning electron microscopy. It shows that use of compatibilizer enhances the dispersions of PLLA in LLDPE matrix. Thermogravimetric (TG) analysis of blends shows the M-g-L 80/4 blend has higher thermal stability among studied blends. The degradation study under different pH of soil compost gives that in alkaline condition and the presence of compatibilizer was favorable for degradation. This blend may be used for packaging application.

Thermal properties and degradation characteristics of polylactide, linear low density polyethylene, and their blends

Melt blending of linear low density polyethylene (LLDPE) and polylactide (PLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without compatibilizer-grafted low density polyethylene maleic anhydride. The blend compositions were optimized for tensile properties as per ASTM D 882-91. On the basis of this, LLDPE 80 [80 wt % LLDPE and 20 wt % poly(L-lactic acid) (PLLA)] and MA-g-low-density polyethylene 80/4 (80 wt % LLDPE, 20 wt % PLLA, and 4 phr compatibilizer) were found to be an optimum composition. The blends were characterized according to their mechanical, thermal, and morphological behavior. Fourier transform infrared spectroscopy revealed that the presence of compatibilizer enhanced the blend compatibility to some extent. The morphological characteristics of the blends with and without compatibilizer were examined by scanning electron microscopy. The dispersion of PLLA in the LLDPE matrix increased with the addition of compatibilizer. This blend may be used for packaging applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Mechanical properties and morphology of polylactide, linear low‐density polyethylene, and their blends

In this study, the degradability of linear low-density polyethylene (LLDPE) and poly(L-lactic acid) (PLLA) blend films under controlled composting conditions was investigated according to modified ASTM D 5338 (2003). Differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectroscopy were used to determine the thermal and morphological properties of the plastic films. LLDPE 80 (80 wt % LLDPE and 20 wt % PLLA) degraded faster than grafted low-density polyethylene–maleic anhydride (M-g-L) 80/4 (80 wt % LLDPE, 20 wt % PLLA, and 4 phr compatibilizer) and pure LLDPE (LLDPE 100). The mechanical properties and weight changes were determined after composting. The tensile strength of LLDPE 100, LLDPE 80, and M-g-L 80/4 decreased by 20, 54, and 35%, respectively. The films, as a result of degradation, exhibited a decrease in their mass. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Degradation behaviors of linear low-density polyethylene and poly(L-lactic acid) blends

Abstract Melt blending of linear low density polyethylene (LLDPE) and poly(l-lactic acid) (PLLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without a compatibilizer-maleic anhydride grafted low density polyethylene. The blend compositions were optimized for tensile properties as per ASTM D 882-91. Based on this, LLDPE 80 (80 wt% LLDPE and 20 wt% PLLA) and M-g-L 80/4 (80 wt% LLDPE, 20 wt% PLLA and 4 parts compatibilizer/100 parts of resin were found to be an optimum composition. The thermal gravimetric profile and thermal endurance of these blends were characterized as per ASTM E1641-07 and E1877-05. The effect of physical aging on mechanical and thermal properties of these blends was evaluated. The PLLA showed the highest Arrhenius activation energy, relative thermal index and strongest thermal endurance of all samples followed by M-g-L 80/4 and LLDPE 80. The thermo-oxidation coefficient improved with addition of compatibilizer in the blends. With increasing pH, the hydrolytic degradation of the blend films increased, while both the tensile strength and the elongation at the break of the blend films decreased.

Thermal degradation and physical aging of linear low density polyethylene and poly(l-lactic acid) blends

Melt blending of linear low density polyethylene (LLDPE) and poly(L-lactic acid) (PLLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without compatibilizer i.e. maleic anhydride grafted low density polyethylene. The blend compositions were optimized for tensile properties as per ASTM D 882-91. Based on this, blend sample having 80 wt % LLDPE and 20 wt % PLLA i.e. sample LLDPE 80 and 80 wt % LLDPE, 20 wt % PLLA and 4 parts compatibilizer per hundred parts of resin i.e. sample M-g-L 80/4 were found to have an optimum composition of performance properties; the effect of blending on the mechanical, thermal and morphological characteristics was done. The blends were characterized using mechanical, thermal and morphological behavior. Morphological characteristics of film surface and fracture surface of polymer blends in absence and presence of compatibilizer were examined using scanning electron microscopy. It has been observed that the dispersion of PLLA in LLDPE matrix improved in presence of compatibilizer. FTIR reveals that the presence of compatibilizer shifts carbonyl peak indicating some increase in interaction between LLDPE and PLLA. Thermogravimetric (TG) analysis of blends showed that the M-g-L 80/4 blend has highest thermal stability as compared to LLDPE/PLLA blends of varying composition. The thermogravimetric profile and thermal endurance of these blends were characterized as per ASTM E164107 and E1877-05. The effect of physical aging on mechanical and thermal properties of these blends was evaluated. PLLA showed the highest Arrhenius activation energy, relative thermal index and strongest thermal endurance of all samples followed by M-gL 80/4 and LLDPE 80. The thermo-oxidation coefficient improved with addition of

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Gursewak Singh

Papers

Thermal properties and degradation characteristics of polylactide, linear low density polyethylene, and their blends

Mechanical properties and morphology of polylactide, linear low‐density polyethylene, and their blends

Degradation behaviors of linear low-density polyethylene and poly(L-lactic acid) blends

Thermal degradation and physical aging of linear low density polyethylene and poly(l-lactic acid) blends

Studies on Degradable Polymeric Blends Based on Poly(Lactic Acid)