Poly(caprolactone) containing highly branched segmented poly(ester urethane)s via A2with oligomeric B3polymerization

Development and Characterization of Tailored Polyurethane Foams for Shock Absorption

In this paper, different types of polyurethane foams (PUR) having various chemical compositions have been produced with a specific density to monitor the microstructure as much as possible. The foam may have a preferential orientation in the cell structure. The cellular polyurethane tends to have stubborn, typical cellular systems with strong overlap reversibility. Free expansion under atmospheric pressure enables formulas to grow until they are refined. Moreover, the physicochemical characterization of the developed foams was carried out. They later are described by apparent density, Shore hardness, Raman spectroscopy analysis, X-ray diffraction analysis, FTIR, TGA, DSC, and compression tests. The detailed structural characterization was used by scanning electron microscope (SEM) and an optical microscope (MO) to visualize the alveolar polymer’s semi-opened cells, highlighting the opened-cell morphology and chemical irregularities. Polyurethane foams with different structural variables have a spectrum characterization that influences the phase separation and topography of polyurethane foam areas because their bonding capability with hydrogen depends on chain extender nature. These studies may aid in shock absorption production; a methodology of elaboration and characterization of filled polyurethane foams is proposed.

Melt polycondensation of carboxytelechelic polyethylene for the design of degradable segmented copolyester polyolefins

Chain-transfer ring-opening metathesis polymerization (CT-ROMP) provided a route to carboxytelechelic polyethylene (PE) with subsequent incorporation into segmented copolymers.

Non-isocyanate Polyurethanes from 1,1'-Carbonyldiimidazole: A Polycondensation Approach

1,1'-Carbonyldiimidazole (CDI) provides a platform to generate high molecular weight polyurethanes from industrially relevant diols and diamines. CDI, which is described in the literature for its use in amidation and functionalization reactions, enables the production of well-defined and stable polyurethane precursors, thus eliminating the need for isocyanates. Herein, the functionalization of 1,4-butanediol with CDI yields an electrophilic biscarbamate, bis-carbonylimidazolide (BCI), which is suitable for further step-growth polymerization in the presence of amines. Elevated reaction temperatures enable the solvent-, catalyst-, and isocyanate-free polycondensation reaction between the BCI monomer and various diamines. The thermoplastic polyurethanes produced from this reaction demonstrate high thermal stability, tunable glass transition temperatures based on incorporation of flexible polyether segments, and mechanically ductile thin films. CDI functionalized diols will allow the preparation of diverse polyurethanes without the use of isocyanate-containing monomers.

A one-pot, solvent-free, and controlled synthetic route for thermoresponsive hyperbranched polyurethanes

Hyperbranched polyurethanes (HPUs) are known for their multifunctionality and versatile properties.