Thermal degradation behaviour of multi‐walled carbon nanotube‐reinforced poly(L‐lactide) nanocomposites

Abstract

BACKGROUND: Polymer/multi‐walled carbon nanotube (MWCNT) composites are one of the most promising alternatives to conventional polymer composites filled with micrometre‐sized fillers. This approach can also be applied for the improvement of mechanical properties and thermal stability of biodegradable aliphatic polyesters, such as poly(L‐lactide) (PLLA), which have been receiving increasing attention due to environmental concerns. Thermal degradation behaviour provides useful information for the determination of the optimum processing conditions and for identification of potential applications of final products. RESULTS: The PLLA/MWCNT composites investigated showed a higher thermal degradation peak temperature and onset temperature of degradation along with a higher amount of residue at the completion of degradation than neat PLLA. Moreover, PLLA/MWCNT composites with a greater MWCNT content showed higher activation energy of thermal degradation than those with a lower MWCNT loading, which confirmed the positive effect of MWCNT incorporation on the enhancement of PLLA thermal stability. CONCLUSION: This study explored the thermal degradation behaviour of PLLA/MWCNT composites by observing the weight loss, molecular weight and mechanical properties during non‐isothermal and isothermal degradation. The incorporation of MWCNTs into the PLLA matrix enhanced considerably the mechanical properties and thermal stability. Copyright © 2009 Society of Chemical Industry

Characterization and thermal degradation of poly(d,l‐lactide‐co‐glycolide) composites with nanofillers

“…Many types of polymers have been used as matrix on CNT nanocomposites: epoxy, polyolefins, polystyrene, polyamide [4, 6], polyurethane, polyimide [3], and also biodegradable polyester such as poly(lactide) (PLA) and its stereoisomeric forms, poly(glycolide) (PGA) and PLGA copolymers [10–13], which can interact covalently or noncovalently with the functionalities on the CNT sidewall.…”

“…To the best of our knowledge, up to now, extensive research has not been reported on the effect of addition HA or CNT to a PLGA copolymer matrix, in terms of thermal behavior and thermal degradation kinetics. Some studies have been published on the activation energy of composites of PLA homopolymer filled with CNT, reporting higher E a values for the nanocomposites compared with the neat polymer [13, 41, 42].…”

Polylactic Acid (PLA) Carbon Nanotube Nanocomposites

“…In a research study by Kim et al, thermal degradation behavior of PLLA/ MWCNT composites was investigated by determination of the molecular weight, mechanical properties, and weight loss during non-isothermal and isothermal degradation [41]. A significant improvement in the mechanical properties and thermal stability of the PLLA matrix was evident after incorporation of MWCNTs.…”

Characterization and thermal degradation kinetics of poly(l -lactide) nanocomposites with carbon nanotubes

“…Depending on the type of polymer used as a composite matrix, the presence of functional groups on CNT sidewalls is more need it. Many types of polymers have been used as matrices in nanocomposites with functionalized or pristine CNT (P‐CNT): epoxy, polyolefins, polystyrene, polyamide , polyurethane, polyimide , and also biodegradable polyesters like poly(glycolide) and poly(lactide) (PLA) . Nanocomposites of PLA and CNT in theory should have the best properties of both components: the biodegradability of PLA and the outstanding reinforcing properties of CNT.…”

“…But, to better understand the synergy between PLA and CNT, we need more insights in the performance of these composites, in terms of mechanical, thermal, and degradation evaluation. For instance, thermogravimetric analysis (TGA) has been widely used to study the thermal stability behavior and kinetics of thermal degradation in polymer composites containing nanofillers, and some authors have reported higher activation energies ( Ea ) in composites of PLA homopolymer with CNT, compared with the pure polymer . Kinetic analysis has two purposes: to evaluate activation energy ( Ea ) and to identify the kinetic model(s) that best describes the degradation process .…”