Composition-property relationship of PCL based Polyurethanes

Download

index.pdf

Date

2012

Author

Güney, Aysun

Metadata

Show full item record

Item Usage Stats

292
views

165
downloads

The desirable properties of polyurethanes (PUs) such as mechanical flexibility associated with chemical versatility make these polymers attractive in the development of biomedical devices. In this study, various segmented polyurethanes were synthesized through polymerization reactions between polycaprolactone (PCL) diol or triol and excess hexamethylene diisocyanate (HDI) with varying NCO/OH ratios and the effect of composition on the properties of the resultant polyurethane films were examined. Initially, isocyanate terminated prepolymers were synthesized through one-shot polymerization, and then these prepolymers were cured by introducing crosslinkages into the structure and thus PUs were obtained. In order to enhance biocompatibility and hydrophilicity of the resulting polymers, heparin was added into the prepolymer before the curing process. The influence of excess HDI as a crosslinker on the degree of H-bond formation between hard-hard segments or hard-soft segments was examined by using Fourier transform infrared-Attenuated total reflectance spectroscopy (FTIR-ATR). Also the effects of HDI content on the chemical, physical and mechanical properties of the polyurethanes were examined with differential scanning calorimetry (DSC), X-Ray diffraction spectroscopy (XRD), dynamic mechanical analyzer (DMA), mechanical tester and goniometer. FTIR- ATR, DSC and DMA analyses showed that use of triol resulted in better network formation and homogenous distribution of hard segments within soft segment matrix. Incorporation of heparin into the polymer matrix produced more hydrophilic films (water contact angle reduced from 80 to 60). Polyurethanes from PCL and HDI in the absence of any solvent, initiator, catalyst or chain extender were successfully synthesized and this kind of synthesis enhanced biocompatibility and increased the potential of polymers for use in biomedical applications.

Subject Keywords

Macromolecules., Polymers.

URI

http://etd.lib.metu.edu.tr/upload/12614253/index.pdf
https://hdl.handle.net/11511/21378

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Synthesis and characterization of copolymers of diisocyanates and dialcohol Keskin, Selda; Usanmaz, Ali; Department of Polymer Science and Technology (2008) This study was aimed to synthesize low molecular weight hydroxyl terminated polyurethane acrylate polymers that can be used in biomedical applications. Acrylate end capping via inter-esterification reaction was successfully achieved with the methacryloyl chloride addition to the hydroxyl ends of the polyurethane at low temperatures. Isocyanate terminated polyurethane acrylates were also synthesized for the sake of comparison. TDI, HDI and MDI were used as diisocyanates for urethane synthesis and they were e...
Synthesis, characterization, and polymerization of polyether bridged thiophene and aniline derivatives Tirkeş, Seha; Önal, Ahmet Muhtar; Department of Polymer Science and Technology (2008) New compounds consisting of 3-thienyl and aniline units linked by polyether bridges have been synthesized and their electrochemical polymerization was performed via constant potential electrolysis and cyclic voltammetry. In the case of 3-thienyl derivatives two compounds, 1,12-di-3-thienyl-2,5,8,11-tetraoxadodecane (MI) and 1,15-di-3-thienyl-2,5,8,11,14-pentaoxapentadecane (MII) were synthesized utilizing literature methods and their corresponding polymers, poly(I) and poly(II) were prepared in an electroly...
Effect of polymer additives on the physical properties of bitumen based composites Doğan, Mehmet; Bayramlı, Erdal; Department of Polymer Science and Technology (2006) Polymer modified bitumen is a binder obtained by the incorporation of various types of polymers in bitumen using mechanical mixing or chemical reactions. There are several factors affecting the properties of polymer modified bituminous composites such as; chemical composition of bitumen, kind of polymer and filler, compatibility of bitumen and polymer, amount of bitumen, polymer and filler, particle size of filler and process conditions. The main objective of this study is to determine the effects of polyme...
Preparation and characterization of chitosanpolyethylene glycol microspheres and films for biomedical applications Günbaş, İsmail Doğan; Hasırcı, Nesrin; Department of Polymer Science and Technology (2007) In recent years, biodegradable polymeric systems have gained importance for design of surgical devices, artificial organs, drug delivery systems with different routes of administration, carriers of immobilized enzymes and cells, biosensors, ocular inserts, and materials for orthopedic applications. Polysaccharide-based polymers represent a major class of biomaterials, which includes agarose, alginate, dextran, and chitosan. Chitosan has found many biomedical applications, including tissue engineering, owing...
Characterization of serpentine filled polypropylene Can, Semra; Tinçer, Teoman; Department of Polymer Science and Technology (2008) In this study, the aim is to prepare polypropylene (PP)/serpentine composites and study their mechanical, thermal and morphological properties. Another objective is to explore whether it is possible to have PP/serpentine nanocomposites with melt intercalation method by using the advantage of the layer silicate structure of serpentine. The most widely used fillers in PP are talc and mica which belong to the phyllosilicates group of silicate minerals. So far, there has been almost no study employing serpentin...

Citation Formats

A. Güney, “Composition-property relationship of PCL based Polyurethanes,” M.S. - Master of Science, Middle East Technical University, 2012.