@article { ISI:000266780000004,
	title = {Solvent-induced self-assembly in cardanol-based urethane methacrylate comb polymers},
	journal = {Journal of Polymer Science Part A-Polymer Chemistry},
	volume = {47},
	number = {12},
	year = {2009},
	month = {JUN},
	pages = {2996-3009},
	publisher = {JOHN WILEY \& SONS INC},
	address = {111 RIVER ST, HOBOKEN, NJ 07030 USA},
	abstract = {<p>We report side chain urethane-methacrylate comb polymers based on the renewable resource cardanol and its saturated analogue 3-pentadecyl phenol and their self-assembly into pores, spheres, vesicles, tubes, and so forth. The monomers were synthesized in one pot by coupling 1 equiv. of isophorone diisocyanate with 1 equiv. of cardanol/pentadecyl phenol followed by coupling with 1 equiv. of hydroxyethyl methacrylate. They were polymerized free radically using benzoyl peroxide as the initiator and were characterized by NMR and FTIR, and their molecular weights were determined by gel permeation chromatography. The unique polymer design had sites for self-organization via hydrogen bonding of the side chain urethane units, pi-pi stacking interactions of the aromatic units as well as interdigitation of the long C(15) alkyl side chains in the polymer. The morphologies of solvent cast polymer films were studied using microscopic techniques such as scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The polymers exhibited three-dimensional honeycomb morphology in CHCl(3), whereas in tetrahydrofuran, they formed spheres. The direct cardanol-derived polymer PCIH showed a tendency for multiple morphologies such as spheres and tubes in tetrahydrofuran. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2996-3009, 2009</p>},
	keywords = {Morphology, polyurethanes, Renewable resources, self-organization},
	issn = {0887-624X},
	doi = {10.1002/pola.23383},
	author = {Rekha, N. and Asha, S. K.}
}
@article { ISI:000263163200021,
	title = {Synthesis and self-organization properties of copolyurethanes based on perylenediimide and naphthalenediimide units},
	journal = {Journal of Polymer Science Part A-Polymer Chemistry},
	volume = {47},
	number = {4},
	year = {2009},
	month = {FEB},
	pages = {1224-1235},
	publisher = {JOHN WILEY \& SONS INC},
	address = {111 RIVER ST, HOBOKEN, NJ 07030 USA},
	abstract = {<p>A series of perylene and naphthalene diimide-containing random copolyurethanes with different ratios of perylene/naphthalene diimide content was synthesized and characterized. Copolymerization improved the solubility of these rigid aromatic diimides, and the copolymers were soluble in common organic solvents like chloroform, tetrahydrofuran, and so forth. The absorption spectra of perylene-based copolymers showed a red-shifted peak at a wavelength of 557 nm corresponding to J-type aggregates. For naphthalene copolymers, the quenching of fluorescence at higher naphthalene incorporation suggested the presence of aggregates because of the extensive pi-pi stacking of the aromatic core. FTIR spectroscopic analysis showed that the hydrogen bonding tendency of the polymer decreased with increase in perylene/naphthalene incorporation. The fluorescence spectra of the perylene polymers were exactly a mirror image of the absorption spectra. The fluorescence spectra of the naphthalene polymers at higher naphthalene incorporation showed a red-shifted excimer like emission peak, which was assigned as static excimers based on their excitation spectra. These polymers could exhibit two types of secondary interaction modes, namely, hydrogen bonding (via urethane linkage) and pi-stacking (via aromatic perylene or naphthalene units) thus highlighting the importance of polymer design in inducing self-organization at both low and high incorporation of the rigid bisimide moieties. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polyrn Chem 47: 1224-1235, 2009</p>},
	keywords = {fluorescence, hydrogen bonding, naphthalene diimide polymers, polyurethane copolymer, self-organization, structure-property relations},
	issn = {0887-624X},
	doi = {10.1002/pola.23233},
	author = {Jancy, B. and Asha, S. K.}
}
