02858nas a2200265   4500008004100000022001400041245013400055210006900189260000800258300001200266490000800278520193200286653002302218653002602241653002002267653002402287653002602311100002502337700001802362700000502380700002202385700003002407700002802437856012702465       2019                        eng d  a0014-305700aAromatic polyesters containing pendant azido groups: synthesis, characterization, chemical modification and thermal cross-linking0 aAromatic polyesters containing pendant azido groups synthesis ch  cJUL  a180-1890 v1163 a<p>A partially bio-based bisphenol containing pendant azido group viz., 4,4'-(5-azidopentane-2,2-diyl) diphenol (AZBPA) was synthesized starting from 4,4'-bis (4-hydroxyphenyl) pentanoic acid. AZBPA was reacted with isophthaloyl chloride (IPC), terephthaloyl chloride (TPC) and a mixture of IPC/TPC (50:50 mol%) by phase transfer-catalyzed interfacial polycondensation route to obtain aromatic polyesters containing pendant azido groups. Copolyesters containing pendant azido groups were also synthesized by polycondensation of different molar proportions of AZBPA and commercially available 4,4'-(1-phenylethane-1,1-diyl) diphenol (BPA-AP) with IPC. Inherent viscosities and number average molecular weights of (co)polyesters were in the range 0.85-1.64 dL/g and 58,900-190,400, respectively, indicating the formation of reasonably high molecular weight polymers. Tough, transparent, and flexible films could be cast from chloroform solutions of these polyesters. X-Ray diffraction analysis showed that (co)polyesters were amorphous in nature. (Co)polyesters were characterized using FT-IR, H-1 NMR spectroscopy, XRD, TGA and DSC analysis. The chemical modification of a representative copolyester containing pendant azido groups was carried out quantitatively using copper-catalyzed azide-alkyne cycloaddition (CuAAC) with two alkynes viz., phenyl acetylene (PA) and ethynyl-4-nitrobenzene (ENB). Additionally, (co)polyesters containing pendant azido groups were thermally cross-linked (170 degrees C/12 h) leading to the formation of network structures based on azide to nitrene decomposition and subsequent reactions on polyester backbone. The selected cross-linked polyesters were characterized by stress-strain measurements. The cross-linked polymers exhibited higher tensile strength and Young's modulus and lower % elongation at break compared to corresponding pristine polyesters containing pendant azido groups.</p>
10aAromatic polyester10aChemical modification10aClick chemistry10aPendant azido group10aThermal cross-linking1 aNagane, Samadhan, S.1 aVerma, Savita1 a1 aSane, Prakash, S.1 aDhanmane, Sushilkumar, A.1 aWadgaonkar, Prakash, P.  uhttps://library.ncl.res.in/content/aromatic-polyesters-containing-pendant-azido-groups-synthesis-characterization-chemical02274nas a2200241   4500008004100000022001400041245008500055210006900140260000800209490000700217520146300224653003901687653001401726653001701740653002501757653002501782100002301807700002601830700000501856700002501861700002801886856011801914       2021                        eng d  a0959-810300aPartially bio-based furyl-functionalized organosoluble poly(ether ether ketone)s0 aPartially biobased furylfunctionalized organosoluble polyether e  cAUG0 v703 a<p>A new series of partially bio-based (co)poly(ether ether ketone)s bearing pendent furyl groups was synthesized by nucleophilic aromatic substitution polycondensation of varying molar proportions of 4,4 `-(furan-2-ylmethylene)bis(2-methoxyphenol) and bisphenol-A with 4,4 `-difluorobenzophenone. The chemical structures, compositions and random nature of (co)poly(ether ether ketone)s were confirmed by NMR spectroscopy. Inherent viscosities and number-average molecular weights of the (co)poly(ether ether ketone)s were in the range 0.74-2.90 dL g(-1) and 33 500-46 300 g mol(-1), respectively, indicating the formation of reasonably high molecular weight polymers. (Co)poly(ether ether ketone)s were readily soluble in common organic solvents and could be cast into tough, transparent and flexible films from chloroform solutions. (Co)poly(ether ether ketone)s exhibited 10% weight loss and glass transition temperatures in the range 429-464 and 152-156 degrees C, respectively. A representative copoly(ether ether ketone) was crosslinked with 1,1 `-(methylenedi-1,4-phenylene)bismaleimide via Diels-Alder reaction to form a crosslinked polymer which showed improved mechanical properties and was recycled twice without significant loss of mechanical properties. Diels-Alder/retro Diels-Alder reaction was demonstrated by studies of sol-gel transformation, solubility tests, DSC and stress-strain measurements. (c) 2020 Society of Chemical Industry</p>
10aaromatic poly(ether ether ketone)s10abio-based10acrosslinking10aDiels-Alder reaction10apendent furyl groups1 aKuhire, Sachin, S.1 aTalanikar, Aniket, A.1 a1 aNagane, Samadhan, S.1 aWadgaonkar, Prakash, P.  uhttps://library.ncl.res.in/content/partially-bio-based-furyl-functionalized-organosoluble-polyether-ether-ketones