title: Improvement of β-TCP/PLLA biodegradable material by surface modification with stearic acid.
abstract: Poly-L-lactide (PLLA) is a biodegradable polymer and used widely. Incorporation of beta tricalcium phosphate (β-TCP) into PLLA can enhance its osteoinductive properties. But the interfacial layer between β-TCP particles with PLLA matrix is easy to be destroyed due to inferior interfacial compatibility of the organic/inorganic material. In this work, a method of β-TCP surface modification with stearic acid was investigated to improve the β-TCP/PLLA biomaterial. The effects of surface modification on the β-TCP were investigated by FTIR, XPS, TGA and CA. It was found that the stearic acid reacted with β-TCP and oxhydryl was formed during the surface modification. Hydrophilicity of untreated or modified β-TCP/PLLA composite was increased by the addition of 10 wt.% β-TCP, but it decreased as the addition amount increased from 10 wt.% to 20 wt.%. Two models were suggested to describe the effect of β-TCP concentration on CA of the composites. Mechanical properties of β-TCP/PLLA composites were tested by bending and tensile tests. Fractures of the composites after mechanical test were observed by SEM. It was found that surface modification with stearic acid improved bending and tensile strengths of the β-TCP/PLLA composites obviously. The SEM results indicated that surface modification decreased the probability of interface debonding between fillers and matrix under load.
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China. Electronic address: mafengcang@163.com.
authors.forename: Fengcang
authors.initials: F
authors.lastname: Ma
authors.affiliation: School of Mechanical Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Sai
authors.initials: S
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Shanghai MicroPort Orthopedics Company with Limited Liability, Shanghai 201318, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Geng
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Xinkuan
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Daihua
authors.initials: D
authors.lastname: He
authors.affiliation: School of Materials Science and Engineering, University of Shanghai for science and technology, Shanghai 200093, China.
authors.forename: Deng
authors.initials: D
authors.lastname: Pan
mesh_terms: D063566:Biodegradable Plastics / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D013229:Stearic Acids / Q000737:chemistry*
chemical_list: D063566:Biodegradable Plastics; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D011091:Polyesters; D013229:Stearic Acids; C485817:beta-tricalcium phosphate; C033616:poly(lactide); C031183:stearic acid
keywords: Hydrophilicity; Interfacial compatibility; Mechanical properties; Surface modification; Tricalcium phosphate