01859nas a2200229 4500008004100000022001400041245007200055210006900127260007300196300001200269490000800281520104300289653002301332653003301355653001601388653002801404653001901432653003301451100002301484700002101507856010101528 2007 eng d a0378-517300aMechanistic investigations of phase behavior in Eudragit (R) blends0 aMechanistic investigations of phase behavior in Eudragit R blend aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT a106-1210 v3433 a

Blends of Eudragit (R) E (EE) and polymeric excipients using thermal analysis and FTIR spectroscopy were examined. The interactions amongst the blend components were quantified in terms of parameters K-1 and K-2 in Schneider equation and were explained on the basis of interactions between the functional groups of the blend constituents investigated by FTIR spectroscopy. EE formed miscible blends with EC and polyelectrolyte complexes increasing in strength in the order: ES < HPMCP < CAP < EL. From the T-g data the weight fraction of EE in the polyelectrolyte complex was determined. The importance of formulating polyelectrolyte complexes in stoichiometric ratios has been highlighted. The duration over which the release can be sustained by polyelectrolyte complexes has been correlated with equilibrium swelling of the polyelectrolyte complex and parameter K, for the first time. This would help in the choice of blend constituents and composition to tailor drug release. (C) 2007 Elsevier B.V. All rights reserved.

10adegree of swelling10aGlass transition temperature10amiscibility10apolyelectrolyte complex10apolymer blends10apolymer-polymer interactions1 aMenjoge, Anupa, R.1 aKulkarni, M., G. uhttps://library.ncl.res.in/content/mechanistic-investigations-phase-behavior-eudragit-r-blends-002232nas a2200229 4500008004100000022001400041245009000055210006900145260010600214300001200320490000700332520133100339653002801670653003301698653002901731653001501760100002801775700002601803700002101829700002801850856012401878 2009 eng d a0014-305700aSynthesis and characterization of new polyimides containing pendent pentadecyl chains0 aSynthesis and characterization of new polyimides containing pend aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcFEB a582-5890 v453 a

A new unsymmetrical aromatic diamine, viz., 4-pentadecylbenzene-1,3-diamine was synthesized through a series of reaction steps starting from 3-pentadecylphenol. 4-Pentadecylbenzene-1,3-diamine was employed to synthesize a series of new polyimides by one-step polycondensation in m-cresol with four commercially available aromatic dianhydrides. viz., 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenone-tetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic anhydride (ODPA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA). Inherent viscosities of resulting polyimides were in the range 0.33-0.67 dL/g and number average molecular weights were in the range 14,700-52,200 (GPC, polystyrene standard). Polyimides containing pendent pentadecyl chains were soluble in organic solvents such as chloroform, m-cresol, N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone (NMP), pyridine and nitrobenzene. Strong and flexible films of polyimides could be cast from their chloroform solutions. Polyimides exhibited glass transition temperature in the range 158-206 degrees C. The temperature at 10% wt. loss (T(10)). determined by TGA in nitrogen atmosphere, of polyimides was in the range 470-480 degrees C indicating good thermal stability. (C) 2008 Elsevier Ltd. All rights reserved.

10aCashew nut shell liquid10aGlass transition temperature10aPendant pentadecyl chain10apolyimides1 aSadavarte, Nilakshi, V.1 aHalhalli, Mahadeo, R.1 aAvadhani, C., V.1 aWadgaonkar, Prakash, P. uhttps://library.ncl.res.in/content/synthesis-and-characterization-new-polyimides-containing-pendent-pentadecyl-chains-003424nas a2200241 4500008004100000022001400041245011300055210006900168260010600237300001400343490000700357520245500364653003302819653002902852653002202881653002802903653002202931100002802953700002102981700002203002700002803024856013003052 2010 eng d a0014-305700aRegularly alternating poly(amideimide)s containing pendent pentadecyl chains: synthesis and characterization0 aRegularly alternating polyamideimides containing pendent pentade aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN a1307-13150 v463 a

Two new aromatic diamines containing preformed amide linkages, viz., N,N'-(4-pentadecyl-1,3-phenylene)bis(4-aminobenzamide) I and N,N'-(4-pentadecyl-1,3-phenylene)bis(3-aminobenzamide) II, were synthesized by reaction of 4-pentadecylbenzene-1,3-diamine with 4-nitrobenzoylchloride and 3-nitrobenzoylchloride, followed by reduction of the respective dinitro derivatives. A series of new poly(amideimide)s was synthesized by poly-condensation of I and II with four commercially available aromatic dianhydrides, viz., pyromellitic dianhydride (PMDA), 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-oxydiphthalic anhydride (ODPA), and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA) in N,N-dimethylacetamide (DMAc) employing conventional two step method via poly(amic acid) intermediate followed by thermal imidization. Reference poly(amideimide)s were synthesized by polycondensation of N,N'-(1,3-phenylene)bis(4-aminobenzamide) and N,N'-(1,3-phenylene)bis(3-aminobenzamide) with the same aromatic dianhydrides. Inherent viscosities of poly(amideimide)s containing pendent pentadecyl chains were in the range 0.37-1.23 dL/g in N,N-dimethylacetamide at 30 +/- 0.1 degrees C indicating the formation of medium to high molecular weight polymers. The poly(amideimide)s containing pendent pentadecyl chains were found to be soluble in N,N-dimethylacetamide, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and pyridine and could be cast into transparent, flexible and tough films from their N,N-dimethylacetamide solution. Wide angle X-ray diffraction patterns exhibited broad halo indicating that the polymers were essentially amorphous in nature. X-ray diffractograms also displayed sharp reflection in the small angle region (20 approximate to 3 degrees) for poly(amideimide)s containing pentadecyl chains indicating the formation of layered structure arising from packing of flexible pentadecyl chains. The glass transition temperatures observed for reference poly(amideimide)s were in the range 331-275 degrees C and those for poly(amideimide)s containing pendent pentadecyl chains were in the range 185-286 degrees C indicating a large drop in T(g), owing to the ``internal plasticization'' effect of pentadecyl chains. The temperature at 10% weight loss (T(10)), determined by TGA in nitrogen atmosphere, were in the range 460-480 degrees C indicating their good thermal stability. (C) 2010 Elsevier Ltd. All rights reserved.

10aGlass transition temperature10aPendent pentadecyl chain10aPoly(amideimide)s10aPreformed amide linkage10athermal stability1 aSadavarte, Nilakshi, V.1 aAvadhani, C., V.1 aNaik, Parimal, V.1 aWadgaonkar, Prakash, P. uhttps://library.ncl.res.in/content/regularly-alternating-polyamideimides-containing-pendent-pentadecyl-chains-synthesis-and-002935nas a2200277 4500008004100000022001400041245015100055210006900206260007300275300001200348490000800360520184600368653000602214653005402220653004302274653002402317653003302341653001502374653002302389100001802412700001402430700003002444700002302474700002802497856013202525 2010 eng d a0921-510700aSynthesis and characterization of polyesters from 2,3-bis (4 `-hydroxy phenyl) quinoxaline and 2,3-bis (2 `-hydroxynaphthalene-6 `-yl) quinoxaline0 aSynthesis and characterization of polyesters from 23bis 4 hydrox aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a186-1920 v1683 a

Two bisphenols containing pendant, quinoxaline moiety; 2,3-bis (4'-hydroxy phenyl) quinoxaline (BHPQ) and 2,3-bis (2'-hydroxynaphthalene-6-yl) quinoxaline (BHNQ) were synthesized and characterized by FT-IR, (1)H, (13)C NMR and mass spectrometry. Aromatic polyesters and copolyesters were prepared by interfacial polymerization from BHPQ or BHNQ and isophthaloyl chloride or terephthaloyl chloride or a mixture of different mole proportions of (IPC + TPC). These polyesters and copolyesters were characterized by spectroscopic technique, viscosity measurement, solubility, thermal stability. DSC and XRD. Polymers had moderate to high molecular weights as evidenced by the inherent viscosities in the range 0.35-0.78 dL/g for BHPQ series and 0.27-0.52 dL/g for BHNQ series. BHPQ polyesters and copolyesters dissolved in m-cresol, NMP and conc. H(2)SO(4) whereas, BHNQ polyesters and copolyesters were readily soluble in NMP, DMAc, (TCE + phenol) and partly soluble in solvent like CHCl(3), pyridine, etc. Wide angle X-ray diffraction (WAXD) results showed that introduction of quinoxaline moiety into polymer chain and aromatic phenyl/rigid naphthyl structures lead to crystalinity. Differentional scanning calorimetry of BHNQ polyesters showed the glass transition temperatures in the range of 131-151 degrees C. BHPQ polyesters did not show any weight loss below 330 degrees C and retained 27-55% weight at 900 degrees C when investigated by TGA under nitrogen atmosphere demonstrating good thermal stability BHNQderived polyesters showed initial decomposition temperatures in range 211-234 degrees C. The structure-property relationships for the mentioned polyesters are analyzed, as these polyesters are of interest as materials for electronics, microelectronics and membrane separation. (C) 2009 Elsevier B.V. All rights reserved.

10a210a3-Bis (2 `-hydroxynaphthalene-6 `-yl) quinoxaline10a3-Bis (4 `-hydroxy phenyl) quinoxaline10aAromatic polyesters10aGlass transition temperature10asolubility10aThermal properties1 aPatil, V., B.1 aMedhi, M.1 aBhairamadgi, Nagendra, S.1 aWadgaonkar, P., P.1 aMaldar, Noormahamad, N. uhttps://library.ncl.res.in/content/synthesis-and-characterization-polyesters-23-bis-4-hydroxy-phenyl-quinoxaline-and-23-bis-2-002347nas a2200241 4500008004100000022001400041245013800055210006900193260000800262300001200270490000700282520146200289653003301751653001801784653002301802653002501825653001601850653003801866100002001904700001501924700003401939856013201973 2019 eng d a1022-134400aImpact of plasticizer addition on molecular properties of polybutadiene rubber and its manifestations to glass transition temperature0 aImpact of plasticizer addition on molecular properties of polybu cJUL a19000030 v283 a

Effect of blending low and high T-g polymer on the structural, spatial, and temporal properties of the polybutadiene rubber are investigated using molecular dynamics simulations. It is elucidated that smaller chain length counterpart of polybutadiene (5mer-OB) acts as plasticizer for the polybutadiene rubber matrix (32mer-PB). Observed flexibility at macroscopic level by plasticizer addition is corroborated at the molecular level in the form of lower conformational rigidity and faster diffusion of polybutadiene chains in the mixtures. It is inferred that plasticizers decreases T-g of the matrix, due to cooperative influence of decreased chain packing and rigidity. Opposite effect is observed in mixtures with high T-g polymer, polystyrene. T-g of the mixtures showed substantial dependence on the type, concentration, chain length as well as miscibility of plasticizers in the matrix. However, the effect of increasing chain length is more pronounced but counter-controlled by the spatially heterogeneous distribution of the plasticizer. Clustering of polystyrene chains induced significant dynamic heterogeneity in the homogeneous polybutadiene matrix, which apparently lead to reduced plasticization effect. Addition of plasticizers in rubber induce discernible changes in the structural and dynamic properties of the rubber matrix, which manifest as the variation in glass transition and explains the real-life activity of plasticizers.

10aGlass transition temperature10aMD Simulation10aplasticizer action10apolybutadiene rubber10aPolystyrene10aspatial and dynamic heterogeneity1 aSharma, Pragati1 aRoy, Sudip1 aKarimi-Varzaneh, Hossein, Ali uhttps://library.ncl.res.in/content/impact-plasticizer-addition-molecular-properties-polybutadiene-rubber-and-its-manifestations02194nas a2200241 4500008004100000022001400041245008700055210006900142260001000211300001000221490000700231520141300238653002401651653001101675653003301686653002401719653001201743100002201755700002001777700002001797700002501817856011001842 2020 eng d a1060-132500aExamining the compatibility of energetic plasticizer DNDA-5 with energetic binders0 aExamining the compatibility of energetic plasticizer DNDA5 with  cJAN 2 a46-540 v573 a

The requirement of developing energetic binders with suitable energetic plasticizers is to enhance the mechanical properties and to reduce glass transition temperature of propellant and explosive formulations. Compatibility of energetic plasticizer 2,4-dinitro-2,4-diazapentane (DNDA-5) with four different energetic binders viz. poly glycidyl nitrate (PGN), poly(3-nitratomethyl-3-methyloxetane) (PLN), glycidyl azide polymer (GAP) and tetra functional glycidyl azide polymer (t-GAP) was studied by using differential scanning calorimeter (DSC) and density functional theory (DFT) methods. Results obtained for the pure binder was compared with the results obtained for binder/plasticizer blend in the parameters of decomposition temperature and the format of the peak which indicated the compatibility or incompatibility of DNDA-5 with the studied binders. Glass transition temperatures of all these blends were determined by low temperature DSC and showed desirable lowering of glass transition temperature with single peak in the case of PLN. The proposed energetic plasticizer DNDA-5 has displayed its compatibility with three binders PGN, PLN and GAP employing thermal techniques. DNDA-5 has been found as incompatible when it is mixed with t-GAP. The predicted relative trend of interaction energies between plasticizer and binder has provided concurrence to results drawn from thermal studies.

10aComputational study10aDNDA-510aGlass transition temperature10aplasticizing effect10athermal1 aVijayalakshmi, R.1 aAgawane, N., T.1 aTalawar, M., B.1 aKhan, Md, Abdul Shaf uhttps://library.ncl.res.in/content/examining-compatibility-energetic-plasticizer-dnda-5-energetic-binders02204nas a2200205 4500008004100000022001400041245014700055210006900202260000900271300001200280490000700292520144700299653003301746653003401779653001301813653001101826100002001837700001501857856012601872 2020 eng d a1539-445X00aGlass transition temperature of polybutadiene and polyisoprene from high temperature segmental relaxation correlation using molecular dynamics0 aGlass transition temperature of polybutadiene and polyisoprene f cJUL  a290-2960 v183 a

Predicting glass transition temperature for rubber and rubber composites is immensely important for tire industry for the development of products and fine-tune process conditions. Molecular dynamics simulation is been used to predict glass transition temperature as a function of molecular-level structural changes, e.g., composition (functional groups), topology, and polymerization. However, prediction of glass transition temperature within experimental error bar from molecular dynamics simulation is only possible from all atomistic description (model) of the system as united atom and coarse-grained models under-predict the values. Conventional way of calculation of glass transition temperature from density (or any other properties which show sharp transition)-temperature plots are computationally very demanding because of atomistic simulations and simulations below the glass transition point, i.e., in glassy state. Here we report a novel method for calculation of glass transition temperature using only segmental relaxation correlation functions calculated at higher temperatures, i.e., above glass transition temperature. We have presented a protocol here and shown for two polymeric systems polybutadiene and polyisoprene. We believe this method cuts the computational cost of predicting glass transition temperature by one-third and will be applicable for industrial applications for structure-property validations.

10aGlass transition temperature10amolecular dynamics simulation10aPolymers10arubber1 aSharma, Pragati1 aRoy, Sudip uhttps://library.ncl.res.in/content/glass-transition-temperature-polybutadiene-and-polyisoprene-high-temperature-segmental