Effects of electron beam irradiation on thermal and mechanical properties of poly(lactic acid) films

The primary aim of this body of work is to investigate the effect of an industrial scale electron beam sterilization process on novel PNVCL-based smart polymers. There is limited literature available that examines the effects of modifying PNVCL by electron beam irradiation, and as a means of potentially enhancing properties such as the lower critical solution temperature and mechanical behavior. Physically crosslinked poly(N-vinylcaprolactam)-vinyl acetate (PNVCL-VAc) copolymers were prepared by photopolymerization and were subsequently exposed to ionizing radiation via electron beam technology. The mechanical characteristics and phase transitions of the physically crosslinked PNVCL samples were tailored by controlling the electron beam irradiation dose. Importantly, PNVCL and PNVCL-VAc samples (5 wt % in solution) underwent a phase transition between 33.5 and 26.5 C, following electron beam irradiation. Furthermore, all samples displayed a Young's modulus between 1024.3 and 1516.4 MPa depending on the addition of copolymer and electron beam irradiation dose. The industrial scale electron beam sterilization process proved successful in enhancing/modifying many key smart polymer properties, and this ability to formulate and sterilize in one step could prove a very attractive approach for many biomedical applications.

Section: Resultssupporting

confidence: 88%

“…Similar results were reported by Mansouri et al . who examined the effect of electron beam radiation on polylactic acid where an increase in the electron beam dose resulted in an increase in both storage and loss modulus …”

Section: Resultsmentioning

confidence: 99%

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Halligan

Murray²,

Hopkins

et al. 2019

“…In the systems in which the fiber was coated, PLA–cotton TPS and PLA TPS –cotton TPS showed a positive coefficient line. According to Pukánsky and other authors, this profile shows that in both cases, the coupling agents (TPS) improved the adhesion.…”

Section: Resultsmentioning

confidence: 63%

“…55–65°C) and a T 10% over 320°C. This degradation process predominantly consists of random main‐chain scission and unzipping depolymerization …”

Section: Resultsmentioning

confidence: 99%

“…Thus, specific cellulose and starch composites that present hydrophilic phases make the θ values smaller and imply a lower surface energy. Thus, the initial contact of the medium with the surface of the material is favored and can increase the retention of water and the fragility of the material . Furthermore, hydrolysis occurs mostly in bulk and depends on other factors, such as stiffness, crystallinity, formation, cracking, and bonding energy.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Poly(lactic acid)–thermoplastic starch–cotton composites: Starch‐compatibilizing effects and composite biodegradability

Macedo

Santos

Rosa

2019

Poly(lactic acid) (PLA) is a biodegradable, brittle, and high-cost polymer, which can be applied over structural components and green packaging. In this study, we reinforced PLA with natural cotton (10 wt %) and thermoplastic starch (TPS; 3 wt %) to obtain a biodegradable and lower cost composite. TPS was incorporated in three distinct ways: it was blended, coated, and blended and coated. In this study, we investigated the compatibilization of TPS in the improvement of matrix-reinforcement adhesion and increase in the tensile behavior without a compromise in biodegradation. The samples were investigated with thermal analysis, dynamic mechanical thermal analysis, tensile testing, scanning electron microscopy, confocal laser scanning microscopy, and hydrolytic degradation. The results show that the coupling effect was more pronounced in the PLA TPS -cotton TPS (hybrid system with PLA and cotton) hybrid system. This formulation presented a higher glass-transition temperature, thermal stability, storage modulus, wettability, and ductility. The TPS addition improved the adhesion between the matrix and starched cotton fiber and retarded abiotic biodegradation. These properties will allow for green applications.

The effects of electron beam radiation on material properties and degradation of commercial PBAT/PLA blend

Iuliano

Nowacka

Rybak

et al. 2019

This work investigates the potential application of e-beam radiation for sterilization of food packaging made of commercial polyester blend of poly(butylene adipate-co-terephthalate) and polylactide known under the trade name Ecovio 23B1. Ecovio film was irradiated at doses of 5, 13, and 26 kGy and the effect of sterilization on the microorganism inactivation ability was performed. The influence of radiation doses on structural and packaging properties such as tensile strength, barrier, and migration properties was also studied. 1 H NMR and FTIR analysis revealed no significant changes in the polymer structure, however, the molar mass of irradiated samples decreased with increasing radiation dose. This result indicated the occurrence of degradation process during radiation, which was confirmed by the thermal analysis and accelerated enzymatic degradation. The packaging properties did not changed significantly and the overall migration for 10% ethanol, isooctane, and MPPO was below the limit for all of the studied samples.