Study on calcium silicatepoly (Ethylene terephthalate-co-caprolactone) biomaterials

การศึกษาวัสดุชีวภาพจากแคลเซียมซิลิเกตและพอลิเมอร์ร่วมเอทิลีนเทอเรฟทาเลต-คาโปแลคโตน

Name: Suebpong Suebwongnat

LCSH: Biomedical materials.

LCSH: calcium silicate.

LCSH: Polyethylene terephthalate.

Othors: Applied Chemistry -- Thesis (Degree of Doctor)

Othors: King Mongkut's Institute of Technology Ladkrabang. -- Applied Chemistry -- Thesis.

Abstract: This thesis aims to study the preparation of calcium silicate/poly(ethylene terephthalate-co-caprolactone) composites (CS/PET-co-PCL) for biomaterial applications. Firstly, the calcium silicate powder (CS) was synthesized by co-precipitation method of calcium nitrate tetrahydrate and tetraethyl orthosilicate using sodium hydroxide as a precipitating agent. Cyclic oligo(ethylene terephthalate) (C-OET) precursor was synthesized by cyclodepolymerization of PET. The neat PET-co-PCL copolyesters were obtained from the mixture of the C-OET precursor and ɛ-caprolactone (CL) cyclics in the presence of dibutyltinoxide (DBTO) catalyst by ring-opening polymerization at 180, 200, 230, and 250 ºC for 8 and 24 hr under vacuum. While the CS/PET-co-PCL was prepared by mixing the as-prepared CS powder in the mixture of the C-OET, CL and DBTO, shaping by uniaxial pressing and ring-opening polymerization at 180 and 200 ºC for 24 hr. The molar ratios of C-OET:CL in the cyclic mixtures were varied, i.e., 50:50, 60:40, 70:30, 80:20, 90:10, and 100:0. The weight percentages of CS:cyclics in the CS/C-OET-CL pre-composites were 50:50 and 60:40. The ¹H-NMR spectra revealed that the structures of ROP PET-co-PCL phases in the composites transformed from block to alternating copolymers when the CL content was increased, resulting in the change of thermal and mechanical properties of CS/PET-co-PCL composites. The melting temperature and compressive strength of the composites decreased with the increment of CL content, however, these properties were significantly increased comparing with both neat CS and PET-co-PCL copolymers. The compressive strengths of the CS/PET-co-PCL composites were compatible with those of various body parts. For morphological studies, the ring-opening polymerized PET-co-PCL film was obtained as the continuous film covering on the CS grains as examined by SEM. The CS/PET-co-PCL composites were reshaped then annealed at 150 °C for 1 hr. The crystallinity and thermal properties of the reshaped and annealed composites were unchanged, indicating that the composites may have thermoplastic elastomer behaviors. The bioactivity tests performed by soaking in simulated body fluid solution (SBF) indicated that the CS/PET-co-PCL composites could induce the formation of phosphate-compounds on their surfaces within 7 days while the neat copolyesters could not. The cytotoxicity was studied by MTT assay, in which the test result revealed that the CS/PET-co-PCL composites were potentially non-toxic to cell. The CS/PET-co-PCL composites which successfully synthesized via ring-opening polymerization were potential candidates for medical applications

King Mongkut's Institute of Technology Ladkrabang. Central Library

Address: Bangkok

Email: Lifelong@kmitl.ac.th

Name: Punnama Siriphannon

Role: Thesis Advisor

Email : kspunnam@kmitl.ac.th

Created: 2014

Modified: 2559-07-08

Issued: 2016-07-08

วิทยานิพนธ์/Thesis

application/pdf

CallNumber: Thesis S85s 2014

eng

DegreeName: Doctor of Philosophy (Applied Chemistry)

Level: Doctoral Degree

Descipline: Applied Chemistry

Grantor: King Mongkut's Institute of Technology Ladkrabang

©copyrights King Mongkut's Institute of Technology Ladkrabang

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