Catalyst- and Solvent-Free “Click” Chemistry: A Facile Approach to Obtain Cross-Linked Biopolymers from Soybean Oil

Energetic polymeric networks prepared via a solvent- and catalyst-free thermal cycloaddition of azide-bearing polymers with alkynes and hydroxyl-isocyanate addition reactions

The construction of azide-bearing polymeric networks using a dipolarophile and a diisocyanate.

RAFT polymerization of bio-based 1-vinyl-4-dianhydrohexitol-1,2,3-triazole stereoisomers obtained via click chemistry

Four 1-vinyl-4-dianhydrohexitol-1,2,3-triazole stereoisomers are prepared from isomannide, isoidide, and isosorbide using an alkylation/CuAAC-ligation/elimination three-step strategy. After characterization of the monomers by NMR, differential scanning calorimetry (DSC), and high-resolution mass spectrometry (HRMS), the corresponding stereocontrolled poly(1-vinyl-4-dianhydrohexitol-1,2,3-triazole)s are obtained by RAFT polymerization using a xanthate chain transfer agent. A systematic investigation of the structure-properties relationship of both the monomers and polymers highlights the significant impact of the dianhydrohexitols stereochemistry on their physical properties (1H and 13C NMR chemical shifts, physical state, Tg, thermal stability and solubility). A particularly original and unexpected behavior is highlighted since the two different isosorbide-based poly(1-vinyl-4-dianhydrohexitol-1,2,3-triazole) stereoisomers exhibit contrasting solubility in water.

PEGylated click polypeptides synthesized by copper-free microwave-assisted thermal click polymerization for selective endotoxin removal from protein solutions

PEGylated click polypeptides (PEG-CPs) containing α-amino side groups as well as PEG segments are designed for selective endotoxin removal from protein solutions. The PEG-CPs are synthesized via copper-free thermal click copolymerization from aspartic (or glutamic) acid-based dialkyne and diazide monomers (containing free amino side groups) and alkyne-terminated mPEGs or dialkyne-terminated PEGs. Microwave-assisting technology is introduced into thermal click chemistry to improve the reaction efficiency. The monomers and polymers are fully characterized using NMR, XPS, and MALDI-TOF MS. After immobilizing the PEGylated click polypeptides onto polystyrene microspheres, the adsorbents exhibit good endotoxin removal selectivity from BSA solutions.

Biopolymers from vegetable oils via catalyst- and solvent-free "click" chemistry: effects of cross-linking density

New monomers were prepared by introducing the azide groups in castor, canola, corn, soybean, and linseed oils. Polymerization of the azidated oils with alkynated soybean oil under thermal "click" chemistry conditions (without using a solvent or a catalyst) yielded fully cross-linked elastomers (1-5) of almost the same density (1.05 × 10(-3) kg/m(3)). The degree of cross-linking gradually increased from the castor-derived polymer (220 mol/m(3)) to the linseed-derived polymer (683 mol/m(3)). A systematic correlation between the degree of cross-linking and the thermal and mechanical properties was observed in these biopolymers. Tensile strength (0.62-3.39 MPa) and glass transition temperature (-5 to 16 °C) increased and the linear thermal expansion coefficient decreased in the series from the canola-derived polymer (2) to the linseed-derived polymer (5). The castor-derived polymer (1) that possesses an additional hydroxyl group per fatty acid chain behaved differently.