01397nas a2200193   4500008004100000022001400041245014300055210006900198260000900267300001200276490000800288520066800296100002300964700002100987700001801008700001901026700002801045856013001073       2018                        eng d  a0014-305700a Synthesis and characterization of partially bio-based polyimides based on biphenylene-containing diisocyanate derived from vanillic acid 0 aSynthesis and characterization of partially biobased polyimides   c DEC  a257-2640 v1093 aA new bio-based biphenylene-containing diisocyanate, namely, 5,5'-diisocyanato-2,2',3,3'-tetramethoxy-1,1'-biphenyl (BDI) was synthesized starting from vanillic acid - a lignin-derived phenolic acid. A series of new partially bio-based polyimides was prepared by polycondensation of BDI with five commercially available aromatic dianhydrides. Polyimides exhibited good solubility in organic solvents and medium molecular weights (Mn (GPC, polystyrene standard) = 25,100-32,200 g mol(-1)). Polyimides showed good thermal stability with 10% degradation temperature and glass transition temperature in the range 459-473 degrees C and 262-329 degrees C, respectively.1 aKuhire, Sachin, S.1 aIchake, Amol, B.1 aGrau, Etienne1 aCramail, Henri1 aWadgaonkar, Prakash, P.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-partially-bio-based-polyimides-based-biphenylene-containing02425nas a2200265   4500008004100000022001400041245011200055210006900167260000800236300001500244490000600259520150600265653002701771653002401798653003001822653001601852653002001868100002501888700002301913700002101936700002601957700002001983700002802003856012802031       2022                        eng d  a2365-654900aSynthesis, characterization and UV-crosslinking of aromatic (Co)polycarbonates bearing pendant azido groups0 aSynthesis characterization and UVcrosslinking of aromatic Copoly  cSEP  ae2022010200 v73 a<p>
	A new series of (co)polycarbonates bearing pendent azido groups was synthesized by polycondensation of varying molar proportions of 4, 4'-(5-azidopentane-2, 2-diyl) diphenol and bisphenol-A with triphosgene. The chemical structures, compositions and random nature of (co)polycarbonates were confirmed by NMR spectroscopy. Inherent viscosities and number-average molecular weights of (co)polycarbonates were in the range 0.63-0.77 dL g(-1) and 35,400-43,400 g mol(-1), respectively indicating the formation of reasonably high molecular weight polymers. (Co)polycarbonates could be cast into tough, transparent and flexible films from chloroform solutions. (Co)polycarbonates were further characterized using IR spectroscopy, XRD, TGA and DSC. The thermal crosslinking of (co)polycarbonates bearing pendant azido groups was studied by DSC analysis. Independently, (co)polycarbonates bearing pendant azido groups were exposed to UV irradiation at wavelength of 254 nm and decomposition reaction of azido groups was monitored by FT-IR spectroscopy. The complete decomposition of azido groups was observed with exposure time of 30 min. The formed cross-linked (co)polycarbonates exhibited improved % char yield values compared to parent (co)polycarbonates. The measurement of mechanical properties of representative crosslinked (co)polycarbonates indicated increase in tensile strength and Young's modulus and decrease in % elongation compared to corresponding parent linear (co)polycarbonates.</p>
10aAromatic polycarbonate10aPendant azido group10asolution polycondensation10aTriphosgene10aUV-crosslinking1 aNagane, Samadhan, S.1 aKuhire, Sachin, S.1 aIchake, Amol, B.1 aTalanikar, Aniket, A.1 aLochab, Bimlesh1 aWadgaonkar, Prakash, P.  uhttps://library.ncl.res.in/content/synthesis-characterization-and-uv-crosslinking-aromatic-copolycarbonates-bearing-pendant