@article { ISI:000265699700015, title = {Control of molecular aggregation in symmetrically substituted pi-conjugated bulky poly(p-phenylenevinylene)s and their copolymers}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {47}, number = {10}, year = {2009}, month = {MAY}, pages = {2631-2646}, publisher = {JOHN WILEY \& SONS INC}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

A new series of symmetrically substituted bulky PPV-copolymers based on poly(bis-2,5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) bearing tricyclodecane (TCD) pendants were synthesized to study the effect of chain aggregation in the pi-conjugated polymer backbone. The composition of the copolymers was varied up to 100 mol \% and the structures of the copolymer were confirmed by NMR and FTIR. The molecular weights of the copolymers were obtained as M(w) = 11,500-1,78,800 depending on the TCD-incorporation in BEH-PPV. The origin of the pi-aggregation was investigated using mixture of solvents (polar or nonpolar) or temperature as external stimuli. Absorption, photoluminescence, and time-resolved fluorescence decay techniques were employed as tools to trace molecular aggregation in solution and solid state. The TCD-substituted bulky copolymers showed almost twice the enhancement in photoluminescence compared with that of BEH-PPV Solvent-induced aggregation studies of copolymers revealed the existence of strong molecular aggregation in BEH-PPV compared with that of bulky copolymers. Variable temperature studies further evidence for the reversibility of molecular aggregation on beating/cooling cycles and showed isosbetic points with respect to free and aggregated polymer chains. Time-resolved fluorescent studies confirmed the existence of free and aggregated pi-conjugated species with a life time of 0.1 to 1.0 ns. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2631-2646, 2009

}, keywords = {conjugated polymers, fluorescence, poly(p-phenylenevinylene), solution properties, Structure-property relationship}, issn = {0887-624X}, doi = {10.1002/pola.23348}, author = {Resmi, R. and Amrutha, S. R. and Jayakannan, M.} } @article { ISI:000276790500011, title = {Synthesis and characterization of new aromatic polyesters containing cardo decahydronaphthalene groups}, journal = {European Polymer Journal}, volume = {46}, number = {4}, year = {2010}, month = {APR}, pages = {709-718}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Three cardo bisphenols containing decahydronaphthalene group viz., 4,4{\textquoteright}-(octahydro-2(1H)-naphthylidene)bisphenol, 4,4{\textquoteright}-(octahydro-2(1H)-naphthylidene)bis-3-methylphenol and 4,4{\textquoteright}-(octahydro-2(1H)-naphthylidene)bis-3,5-dimethylphenol were synthesized starting from commercially available 2-naphthol and were utilized for synthesis of new aromatic polyesters by phase transfer-catalyzed interfacial polycondensation with isophthaloyl chloride, terephthaloyl chloride and a mixture of isophthaloyl chloride and terephthaloyl chloride (50:50 mol \%). Inherent viscosities and number average molecular weights (M(n)) of polyesters were in the range 0.35-0.84 dL/g and 13300-48,500 (Gel Permeation Chromatography, polystyrene standard), respectively. Polyesters were readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and 1-methy1-2-pyrrolidinone at room temperature and could be cast into tough, transparent and flexible films from their chloroform solutions. Wide-angle X-ray diffraction measurements revealed the amorphous nature of polyesters. The glass transition temperature of polyesters was in the range 207-287 degrees C. The temperature at 10\% weight loss (T(10)), determined from thermogravimetric analysis of polyesters, was in the range 425-460 degrees C indicating their good thermal stability. (C) 2010 Elsevier Ltd. All rights reserved.

}, keywords = {bisphenol, Cardo, Decahydronaphthalene, polyester, Structure-property relationship}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2009.12.028}, author = {Honkhambe, Pandurang N. and Bhairamadgi, Nagendra S. and Biyani, Mahesh V. and Wadgaonkar, Prakash P. and Salunkhe, Manikrao M.} } @article { ISI:000360002300005, title = {Studies on melt processable biocomposites of polylactic acid}, journal = {Journal of Polymers and the Environment}, volume = {23}, number = {3}, year = {2015}, month = {SEP}, pages = {321-333}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Melt processable microcrystalline cellulose (MCC)/poly(lactic acid) (PLA) composites were successfully prepared by twin-screw extrusion. Several characterization techniques were used to investigate the effect of MCC on rheological behavior, morphology, crystallization and melting behavior of the PLA and structure-property correlation of the MCC/PLA composites has been established. Rheological measurements showed that the addition of MCC has a dramatic influence on the low frequency relaxations of PLA chains and above 5 \% of MCC, it forms percolated network structure. Differential scanning calorimeter analysis showed that MCC acted as nucleating agent enhancing crystallization below the percolation concentration. Properties of MCC/PLA composites have been compared with that of talc and CaCO3 filled composites. Talc is found to be more effective in crystallizing PLA than MCC and CaCO3. MCC/PLA composites are found be melt processable like that of talc and CaCO3 filled PLA composites.

}, keywords = {Biopolymers, composites, Rheological properties, Structure-property relationship}, issn = {1566-2543}, doi = {10.1007/s10924-014-0668-5}, author = {Joseph, Seena and Deenadayalan, E. and Mahanwar, Prakash A.} }