Fabrication of polymer materials from their cyclodextrin inclusion complexes

Inclusion 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 enzyme. 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.; 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 polymer guests. PC crystals formed upon the coalescence from the narrow channels in the CD host lattice are possibly more chain-extended and certainly more stable than normal 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). Examination of as-received and IC coalesced nylon-6 samples shows 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 CD-IC crystals are coalesced, an intimately mixed blend of the polymers is 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. 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. Spectroscopic results illustrate that there is intimate mixing existing in the IC coalesced blend, but not in their solution cast physical blend.