Yes / Highly-oriented poly (lactic acid) (PLA) with bionic micro-grooves was
fabricated through solid hot drawing technology for further improving the mechanical
properties and blood biocompatibility of PLA. In order to enhance the melt strength
and thus obtain high orientation degree, long chain branched PLA (LCB-PLA) was
prepared at first through a two-step ring-opening reaction during processing. Linear
viscoelasticity combined with branch-on-branch (BOB) model was used to predict
probable compositions and chain topologies of the products, and it was found that the
molecular weight of PLA increased and topological structures with star like chain
with three arms and tree-like chain with two generations formed during reactive
processing, and consequently draw ratio as high as1200% can be achieved during the
subsequent hot stretching. With the increase of draw ratio, the tensile strength and
orientation degree of PLA increased dramatically. Long chain branching and
orientation could significantly enhance the blood compatibility of PLA by prolonging
clotting time and decreasing platelet activation. Micro-grooves can be observed on the
surface of the oriented PLA which were similar to the intimal layer of blood vessel,
and such bionic structure resulted from the formation of the oriented shish kebab-like
crystals along the draw direction.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/8031 |
| Date | 20 January 2016 |
| Creators | Li, Z., Ye, L., Zhao, X., Coates, Philip D., Caton-Rose, Philip D., Martyn, Michael T. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Accepted Manuscript |
| Rights | © 2016 Wiley Periodicals, Inc. Full-text reproduced in accordance with the publisher’s self-archiving policy. This is the peer reviewed version of the following article: Li Z, Ye L, Zhao X, Coates PD, Caton- Rose F and Martyn MT (2016) High orientation of long chain branched poly (lactic acid) with enhanced blood compatibility and bionic structure. Journal of Biomedical Materials Research, Part A. 104(5): 1082-1089, which has been published in final form at http://dx.doi.org/10.1002/jbm.a.35640. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/ WileyCDA/Section/id-820227.html#terms). |
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