Synthesis and properties of highly branched poly(urethane–imide) via A2 + B3 approach

Synthesis and Properties of Novel Thermoplastic Poly(ester-ether-imide) Elastomers Derived from 4,4′-bis(N-trimellitimide)-diphenylether Unit with Excellent Thermal Stability

“…The stress at break of PEEIs increases from 11.53 to 13.86 MPa, but the elongation at break decreases from 552.82 to 405.42% with the increment imide content. This can be attributed to the intermolecular interactions including the intermolecular force and hydrogen bonding were enhanced because of large amounts of imide groups in per macromolecule (31). Meanwhile, the flexibility and elasticity were provided by the soft segment, when the soft segment in the molecular chains decreased, resulting in the elongation at break decreasing.…”

Degradation Kinetics of Model Hyperbranched Chains with Uniform Subchains and Controlled Locations of Cleavable Disulfide Linkages

“…where K = 4π 2 n 2 (dn/dC) 2 /(N A λ 0 4 ) and q = (4πn/λ 0 ) sin(θ/2) with n, C, dn/dC, N A , and λ 0 being the refractive index, the concentration of the polymer solution, the specific refractive index increment, Avogadro's number, and the wavelength of light in a vacuum, respectively. The dn/dC value of polystyrene in THF is 0.186 mL/ g. 12,13 In dynamic LLS, 46 the Laplace inversion of each measured intensity−intensity time correlation function G (2) (q,t) in the selfbeating mode can result in a line-width distribution G(Γ). G(Γ) can be converted to a translational diffusion coefficient distribution G(D) or further to a hydrodynamic radius distribution f(R h ) via the Stokes− Einstein equation, R h = (k B T/6πη 0 )/D, where k B , T, and η 0 are the Boltzmann constant, the absolute temperature, and the solvent viscosity, respectively, by using both the cumulants and CONTIN analysis.…”

“…In the past two decades, various nonideal hyperbranched structures with uncontrollable branching subchains have been extensively prepared and used for the structure–property investigation. − This is due to the fact that the preparation of an ideal model hyperbranched structure with uniform and adjustable subchains between any two neighboring branching points is rather difficult because of synthetic methodology limitation, , which seriously hinders the relevant structure–property study. , Recently, using a novel seesaw-type macromonomer B∼∼A∼∼B as the precursor in self-polycondensation reaction, where the reactive A and the two B groups are located at the chain center and the two chain ends, respectively, − we have successfully prepared model hyperbranched chains. Moreover, we have experimentally, for the first time , established the scaling laws between their sizes ( R ), intrinsic viscosities ([η]), and molar masses ( M ); , found how these chains pass through a small cylindrical nanopore under an elongational flow field; , and prepared amphiphilic hyperbranched block copolymer chains and studied their interchain and intrachain association in dilute and semidilute solutions …”

Synthesis and characterization of poly(urethane-imide) nanocomposite films filled with iron oxide–silica and clay–silane–iron oxide nanoparticles

“…Reacting an isocyanate-terminated PU prepolymer with dianhydride is a convenient method to introduce the imide function into the PU backbone. [16][17][18] For example, various attempts to incorporate PI units into PUs can be classified as (a) reaction of isocyanate-terminated PU prepolymers and anhydrides with organoclay 19,20 ; (b) reaction of isophorone diisocyanate, polycarbonatediol with 3,3 0 ,4,4 0 -benzophen-onetetracarboxylic dianhydride 21 ; (c) reaction of blending PU prepolymer with different ratio of poly(amide acid) 22 ; (d) reaction of epoxy resins with PUI 23,24 ; (e) synthesis of inherently flame retardant and antidripping thermoplastic poly(imides-urethane)s 25 ; (f) synthesis of flame retarded PUI by 4,4 0 -diphenylmethane diisocyanate (MDI), poly(tetrahydrofuran), pyromellitic anhydride (PMDA), and hydroxyl-terminated poly(dimethylsiloxane) used as flame retardants. 26 During the last decade, magnetic nanocomposite material development has led to discovering spectacular new phenomena, with potential applications in multidimensional fields.…”