A constitutive law for degrading bioresorbable polymers. (June 2016)

• Record Type: Journal Article
• Authors: Samami, Hassan; Pan, Jingzhe
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 59(2016)
• Page Start: 430
• Page End: 445
• Publication Date: 2016-06
• Subjects: Effective moduli -- Cavity inclusion -- Crystal inclusion -- Crystalline and amorphous polymers -- Multi-phase material; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2016.02.026
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: This paper presents a constitutive law that predicts the changes in elastic moduli, Poisson's ratio and ultimate tensile strength of bioresorbable polymers due to biodegradation. During biodegradation, long polymer chains are cleaved by hydrolysis reaction. For semi-crystalline polymers, the chain scissions also lead to crystallisation. Treating each scission as a cavity and each new crystal as a solid inclusion, a degrading semi-crystalline polymer can be modelled as a continuum solid containing randomly distributed cavities and crystal inclusions. The effective elastic properties of a degrading polymer are calculated using existing theories for such solid and the tensile strength of the degrading polymer is predicted using scaling relations that were developed for porous materials. The theoretical model for elastic properties and the scaling law for strength form a complete constitutive relation for the degrading polymers. It is shown that the constitutive law can capture the trend of the experimental data in the literature for a range of biodegradable polymers fairly well.