Flat Die Extruded Biocompatible Poly(Lactic Acid) (PLA)/Poly(Butylene Succinate) (PBS) Based Films

Abstract

Biodegradable polymers are promising materials for films and sheets used in many widely diffused applications like packaging, personal care products and sanitary products, where the synergy of high biocompatibility and reduced environmental impact can be particularly significant. Plasticized poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) blend-based films, showing high cytocompatibility and improved flexibility than pure PLA, were prepared by laboratory extrusion and their processability was controlled by the use of a few percent of a commercial melt strength enhancer, based on acrylic copolymers and micro-calcium carbonate. The melt strength enhancer was also found effective in reducing the crystallinity of the films. The process was upscaled by producing flat die extruded films in which elongation at break and tear resistance were improved than pure PLA. The in vitro biocompatibility, investigated through the contact of flat die extruded films with cells, namely, keratinocytes and mesenchymal stromal cells, resulted improved with respect to low density polyethylene (LDPE). Moreover, the PLA-based materials were able to affect immunomodulatory behavior of cells and showed a slight indirect anti-microbial effect. These properties could be exploited in several applications, where the contact with skin and body is relevant.

Skin-Compatible Biobased Beauty Masks Prepared by Extrusion

“…The possible modulation of melt viscosity by finely tuning PHA/biopolyesters blend compositions is thus a possibility suggested by the present results that could be exploited for specific applications in the packaging, cosmetic and biomedical fields and connected processing methodologies. The possibility of obtaining films by flat die extrusion could be relevant for producing beauty masks, cosmetic pads or personal care films based on bioplastics [17]. Flat die extrusion can be better in the case that the production of beauty masks should be done considering a bigger scale than the one considered in compression molding.…”

“…However, their preparation was based on compression molding of biopolymeric powder with calcium carbonate as additive. This methodology is different from the ones currently used in industry to prepare bioplastic flat films characterized by a high productivity [17][18][19] and therefore can limit the real feasibility of the process.…”

Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

“…To overcome these limits, many attempts were done to improve the PLA/PBS blends properties via plasticization. To this purpose, in order to have a completely biobased product, the use of a suitable biobased plasticizer is of fundamental importance [25]. PLA/PBS blends plasticized with poly(ethylene) glycol (PEG) have been investigated and an increment in elongation at break and softness thanks to plasticization were reported [1,26,27].…”

“…As a starting point, and on the basis of previous studies [25,[31][32][33][34], in this work, a PLA/PBSA blend plasticized with ATBC is considered the matrix for producing nanobiocomposites containing CNs as functional filler.…”

“…In this work, starting from a PLA/PBS/ATBC matrix, where the ratio between the various components was selected based on a previous work [25], bionanocomposites including CNs were prepared. The effect of a melt strength enhancer and contemporarily of CNs alone or mixed with starch was analyzed.…”