Fabrication of Polymer Materials from Their Cyclodextrin Inclusion Complexes

dc.contributor.advisorAlan E. Tonelli, Committee Chairen_US
dc.contributor.authorWei, Minen_US
dc.date.accessioned2010-04-02T19:19:31Z
dc.date.available2010-04-02T19:19:31Z
dc.date.issued2003-10-28en_US
dc.degree.disciplineFiber and Polymer Scienceen_US
dc.degree.leveldissertationen_US
dc.degree.namePhDen_US
dc.description.abstractInclusion complexed (IC) and coalesced biodegradable poly(ε-caprolactone) (PCL), poly(L-lactic acid) (PLLA), and their diblock copolymer (PCL-b-PLLA) were achieved by forming ICs between host α-cyclodextrin(α-CD) and guest PCL, PLLA, and PCL-b-PLLA, followed by removing the α-CD host with an amylase enzyme. The melting and crystallization behavior of these CD-IC treated polymers are investigated. Both isothermal and nonisothermal crystallization studies demonstrate that the PCL and PLLA blocks in the IC-coalesced samples are more readily and homogeneously crystallized than those in the as-synthesized samples or their physical blend, even though the level of crystallinity in the IC-coalesced diblock copolymer is significantly lower. Moreover, unlike the as-synthesized diblock copolymer, the crystallization of PCL and PLLA blocks in the IC-coalesced diblock copolymer are not influenced by their covalent connection. Poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) samples have been produced by the coalescence of their segregated, extended chains from the narrow channels of the crystalline inclusion complexes formed between the γ-cyclodextrin (γ-CD) host and PET and PC guests. Experimental observations of PET and PC samples coalesced from their crystalline ICs suggest structures and morphologies that are different from those of samples obtained by ordinary solution and melt processing techniques. PC crystals formed upon the coalescence of highly extended and segregated PC chains from the narrow channels in the CD host lattice are possibly more chain-extended and certainly more stable than chain-folded PC crystals. The coalesced PET melt rapidly recrystallizes during the attempted quench, and so upon reheating, it displays neither a glass transitions temperature (Tg) nor a crystallization exotherm but simply remelts at the as-coalesced melting temperature (Tm). An inclusion complex between nylon-6 and α-cyclodextrin was obtained and we attempted to use the formation and subsequent disassociation of the nylon-6/α-CD inclusion complex to manipulate the properties of nylon-6. Examination of as-received and IC coalesced nylon-6 samples show that dominated α-form crystalline phase of nylon-6 and a great increase in crystallinity are in the coalesced sample. When inherently immiscible polymers are included as guests in the narrow channels of their common inclusion complexes formed with host cyclodextrins and then these polymer-1/polymer-2-CD-IC crystals are coalesced, an intimately mixed blends of the polymers are obtained. Polycarbonate (PC)/poly(methyl methacrylate) (PMMA) blends coalesced from their common γ-CD-ICs are amorphous and generally exhibit single glass transitions at temperature (Tg) between those of pure PC and PMMA. FTIR spectroscopy suggests an intimate mixing of and possible specific interactions between PC and PMMA chains in the coalesced blends. An attempt to achieve an intimate blend between nylon 6 and nylon 66 by forming and dissociating their common α-CD-IC was also made. Experimental results demonstrate that α-cyclodextrin can only host single nylon polymer chains in the IC channels. Spectroscopic results illustrate that there is intimate mixing existing in the IC coalesced blend, but not in their solution cast physical blend.en_US
dc.identifier.otheretd-10132003-182640en_US
dc.identifier.urihttp://www.lib.ncsu.edu/resolver/1840.16/5765
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectpolymeren_US
dc.subjectpolymer blenden_US
dc.subjectengineering polymersen_US
dc.subjectbiomaterialsen_US
dc.subjectinclusion complexesen_US
dc.titleFabrication of Polymer Materials from Their Cyclodextrin Inclusion Complexesen_US

Files

Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
etd.pdf
Size:
8.87 MB
Format:
Adobe Portable Document Format

Collections