Plasma polymers with controlled degradation behaviour

Abstract

Classical “wet“chemistry methods can produce polymers with well-defined molecular structure, but many types of polymers are difficult to prepare with significant degree of crosslinking without residues of the crosslinking agent. On the other hand, plasma polymers usually have very high degree of crosslinking but nearly random molecular structure. Plasma assisted vapour thermal deposition combines both methods. Classical polymers are heated in a crucible at low pressure and the released oligomeric fragments of the polymer chain are repolymerized in a glow discharge into a thin film. The number of well-preserved monomeric units between the crosslinks can be tuned e.g. from units to tens. Poly-lactic acid (PLA) belongs to a special class of biodegradable polymeric materials. In this work, plasma assisted vapour thermal deposition was utilized to prepare PLA plasma polymers. Molar weights and chemical composition of the “precursor” polymer and of the thin films have been characterized. As the measure of degradability, behaviour of the polymers during hydrolysis has been studied using spectroscopic ellipsometry and liquid chromatography. Possibility to prepare plasma polymer films with controlled degradability was demonstrated. © 2018 TANGER Ltd. All Rights Reserved.