02232nas 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<p>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.</p>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<p>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.</p>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-0