Plasticized chitosan/polyolefin films produced by extrusion.

Plasticized chitosan and polyethylene blends were produced through a single-pass extrusion process. Using a twin-screw extruder, chitosan plasticization was achieved in the presence of an acetic acid solution and glycerol, and directly mixed with metallocene polyethylene, mPE, to produce a masterbatch. Different dilutions of the masterbatch (2, 5 and 10 wt% of plasticized chitosan), in the presence of ethylene vinyl acetate, EVA, were subsequently achieved in single screw film extrusion.

High performance polyethylene/thermoplastic starch blends through controlled emulsification phenomena.

The emulsification efficacies of a range of compatibilizers for polyethylene/thermoplastic starch blends have been studied and a detailed morphological and mechanical analysis has been conducted. It is shown that polyethylene-maleic anhydride terpolymers containing elastomeric segments provided excellent emulsification of PE/TPS blends with a fine morphology (volume diameter of 1.4 μm; number average diameter of 600 nm).

Controlling burst and final drug release times from porous polylactide devices derived from co-continuous polymer blends.

This work has demonstrated that it is possible to exercise a wide range of control over both the initial burst release and the final drug release times from porous polylactide (PLA) devices derived from cocontinuous polymer blends. Two strategies were used: a layer-by-layer polyelectrolyte surface deposition approach on the porous PLA surface and the application of a partially closed-cell protocol. A PLA porous substrate with a pore size of 1.

Smooth muscle cell adhesion in surface-modified three-dimensional copolymer scaffolds prepared from co-continuous blends.

In this article, tissue-engineering scaffolds were fabricated from P(epsilon-CL-co-D,L-LA)-PEG-P(epsilon-CL-co-D,L-LA) copolymers using co-continuous blends with polystyrene as the porogen phase. By means of static annealing and following extraction of the porogen phase, pore sizes (channel widths) in the range of 15-350 microm were obtained. Smooth muscle cells were seeded in three-dimensional fibronectin-modified scaffolds of two different pore sizes.

Porous devices derived from co-continuous polymer blends as a route for controlled drug release.

In this study we examine the release profile of bovine serum albumin (BSA) from a porous polymer matrix derived from a co-continuous polymer blend. The porosity is generated through the selective extraction of one of the continuous phases. This is the first study to examine the approach of using morphologically tailored co-continuous polymer blends as a template for generating porous polymer materials for use in controlled release.

Characterization, degradation, and mechanical strength of poly(D,L-lactide-co-epsilon-caprolactone)-poly(ethylene glycol)-poly(D,L-lactide-co-epsilon-caprolactone).

A series of three biocompatible P(CL-co-LA)-PEG-P(CL-co-LA) copolymers were synthesized using ring-opening polymerization and characterized by 1H-NMR, gel permeation chromatography, DSC, dynamic-mechanical analysis, and X-ray diffraction. The number of monomer units was kept constant, while the D,L-LA fraction was varied so as to constitute 0, 30, or 70% of the end segments. The molecular weights were sufficiently high to eventually permit 3D scaffold preparation.

Controlled preparation and properties of porous poly(L-lactide) obtained from a co-continuous blend of two biodegradable polymers.

This study prepares porous PLLA from a blend of two biodegradable polymers. This approach is based on a detailed and quantitative morphology control of the blends. Co-continuous blends comprised of poly(L-lactide)/poly(epsilon-caprolactone) PLLA/PCL, were prepared via melt processing.

Morphology control in co-continuous poly(L-lactide)/polystyrene blends: a route towards highly structured and interconnected porosity in poly(L-lactide) materials.

Poly(L-lactide) is a biodegradable polymer primarily used in biomedical applications. In this paper, both the microstructure and the region of dual-phase continuity are examined for binary and compatibilized poly(L-lactide)/polystyrene blends (PLLA/PS) prepared by melt mixing. The blends are shown to be completely immiscible with an interfacial tension of 6.