Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM

Abstract

This work investigates preparation by extrusion of microcellular antimicrobial polylactide (PLA) with an additive, the latter comprising 1% potassium aluminum sulfate dodecahydrate (ALUM), and 3% or 5% of a mixture of sodium hydrogen carbonate and sodium dihydrogen phosphate (1:1). Study was made as to the properties of the materials, their hydrolysis, release profiles, and antimicrobial properties in comparison with the pure polymer. Measuring the molecular weight of samples by gel permeation chromatography revealed that, during thermal processing, the molecular weight of the PLA prepared with additives mentiond above had reduced by approximately 43%. A mechanical test confirmed a decline in mechanical properties after processing as compared with the pure PLA. Release of the antimicrobial compound and the subsequent antimicrobial activity against Staphylococcus aureus and Escherichia coli was evaluated according to ISO 22196:2007. The release of ALUM from the microcellular specimens took place in two steps. During the first 10 days, the rate of release was extremely high in contrast with the remaining period.However, the release rate of the nonporous sample was seen to equal less than 1% in the first 10 days, a phenomenon probably arising through its less active surface.

Effect of Abiotic Degradation on the Colorimetric Analysis, Mechanical Properties and Morphology of PLA Composites with Linen Fibers

“…In order to make it suitable for special applications, PLA is modified by the addition of fillers or preparation of blends [8,19,22,26]. These include starch -to decrease the breakdown time of the polymer and reduce the manufacturing costs, and cellulose fibers -to enhance thermal resistance and rigidity.…”

Polylactide/Polyvinylalcohol-Based Porous Bioscaffold Loaded with Gentamicin for Wound Dressing Applications

“…Thermal properties of bioscaffolds before and after thermal treatment were investigated by DSC on a DSC1 STAR system (Mettler Toledo, Greifensee, Switzerland). The preparation of samples has been adopted from our previous paper [ 34 ]. In brief, approximately 5 mg of each bioscaffold was placed in an aluminum pan.…”

“…The region of glass-transition temperature (T g ) was determined from the second heating scan. The degree of crystallinity (χ c ) was calculated according to the Equation (1) [ 34 ]: where ΔH m is the heat of fusion, ΔH c represents the enthalpy of cold crystallization, and is the tabulated heat of fusion for a theoretically 100% crystalline PLA homopolymer (93.1 J g −1 ) [ 34 ].…”

“…The region of glass-transition temperature (T g ) was determined from the second heating scan. The degree of crystallinity (χ c ) was calculated according to the Equation (1) [34]:…”

“…where ∆H m is the heat of fusion, ∆H c represents the enthalpy of cold crystallization, and ∆H 0 m is the tabulated heat of fusion for a theoretically 100% crystalline PLA homopolymer (93.1 J g −1 ) [34].…”