Improving the shape stability and enhancing the properties of layer dependent material extruded biodegradable polylactic acid for thin implants

Abstract

Purpose

This paper aims to establish an appropriate annealing method, which is necessary for shape stability and to evaluate their potential degradation performance of 1-, 3- and 5-layer material extruded polylactic-acid specimens by enhancing their thermal and mechanical properties.

Design/methodology/approach

The distortion of each layered printed specimen subjected to degradation was calculated in x- and y-direction. Each layered specimen was subjected to annealing at 70°C, 80°C and 90°C for 2 h and at 80°C for 1, 4, 8 and 16 h. Thermal, molecular weight and mechanical properties were calculated using, differential scanning calorimetry, gel permeation chromatography and tensile testing machine, respectively.

Findings

In the x-direction, distortion was 16.08 mm for one-layer non-annealed printed specimens and decreased by 73% and 83% for 3- and 5-layer, respectively, while each layered non-annealed specimen subjected to degradation at 37°C for one month. Within the outlined study, annealing treatment enhances properties such as the degree of crystallinity (%χ) up to 34%, Young’s modulus (E) by 30% and ultimate tensile strength by 20% compared to the non-annealed specimens.

Practical implications

The future research accomplishments will be concentrated on the design, development and optimisation of degraded biomedical implants using material extrusion thin films including drug delivery system and fixation plates.

Originality/value

The printed thin specimens subjected to degradation were investigated. This research developed a new understanding of the effect of the annealing temperature and time on the mechanical, thermal and molecular weight properties for each layered specimen.

Citation

Ekinci, A., Han, X., Gleadall, A. and Johnson, A.A. (2021), "Improving the shape stability and enhancing the properties of layer dependent material extruded biodegradable polylactic acid for thin implants", Rapid Prototyping Journal, Vol. 27 No. 6, pp. 1101-1107. https://doi.org/10.1108/RPJ-05-2020-0108