Minimizing the time gap between service lifetime and complete resorption of degradable melt-spun multifilament fibers. (May 2019)

• Record Type: Journal Article
• Authors: Fuoco, Tiziana; Mathisen, Torbjörn; Finne-Wistrand, Anna
• Is Part Of: Polymer degradation and stability. Volume 163(2019)
• Page Start: 43
• Page End: 51
• Publication Date: 2019-05
• Subjects: Degradable copolymers -- Poly(l-lactide-co-trimethylene carbonate) -- Melt-spun multifilament fibers -- Service lifetime -- Bulk degradation; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2019.02.026
• Languages: English
• ISSNs: 0141-3910

Abstract

Abstract: We have succeeded to modulated the degradation rate of poly(l -lactide) (PLLA) melt-spun multifilament fibers to extend the service lifetime and increase the resorption rate by using random copolymers ofl -lactide and trimethylene carbonate (TMC). The presence of TMC units enabled an overall longer service lifetime but faster degradation kinetics than PLLA. By increasing the amount of TMC up to 18 mol%, multifilament fibers characterized by a homogenous degradation profile could be achieved. Such composition allowed, once the mechanical integrity was lost, a much longer retention of mechanical integrity and a faster rate of mass loss than samples containing less TMC. The degradation profile of multifilament fibers consisting of (co)polymers containing 0, 5, 10 and 18 mol% of TMC has been identified during 45 weeks in vitro hydrolysis following the molecular weight decrease, mass loss and changes in microstructure, crystallinity and mechanical properties. The fibers degraded by a two-step, autocatalyzed bulk hydrolysis mechanism. A high rate of molecular weight decrease and negligible mass loss, with a consequent drop of the mechanical properties, was observed in the early stage of degradation for fibers having TMC content up to 10 mol%. The later stage of degradation was, for these samples, characterized by a slight increase in the mass loss and a negligible molecular weight decrease. Fibers prepared with the 18 mol% TMC copolymer showed instead a more homogenous molecular weight decrease ensuring mechanical integrity for longer time and faster mass loss during the later stage of degradation. Graphical abstract: Image 1 Highlights: Trimethylene carbonate (TMC) is an efficient comonomer to extend the service lifetime and increase the degradation rate of PLLAfibers. PLLA and LA/TMC copolymers fibers degrade by an autocatalyzed two-stage bulk hydrolysis mechanism. The time between the loss of mechanical properties and the resorption can be minimized by increasing the TMC content. 18 mol% of TMC allows longer mechanical support and increases the rate of mass loss when the mechanical integrity is lost.