Synthesis of superporous hydrogels as tissue engineering scaffolds via inverse high internal phase emulsion (i-HIPE) polymerization.

The determination of single-chain properties for heterogeneous molecules such as a rigid-flexible block copolymer requires the use of solvents capable of reducing selective interactions involving the blocks and the diluent. Molecular dispersion is displayed by a two-block copolymer of benzoyl-terminated poly(p-benzamide) (poly(imin0-1,4-phenylenecarbonyl) and anilino-terminated poly(m-phenyleneisophthalamide) in 96 wt.-% sulfuric acid. For a series of such copolymers, intrinsic viscosities were measured avoiding degradation effects due to H2S04. The intrinsic viscosity ([a]) of the copolymers was found to decrease with increasing length of the flexible block, but [a] remained larger than the value corresponding to an equimolar blend of rigid and flexible homopolymers. These results are explained by theoretical considerations within the framework of the hydrodynamic behavior of single rodlike and single coiled macromolecules. a) part 1 : cf. ref. l). b, Structure-based IUPAC name for poly(p-benzamide) is: poly(imino-1 ,Cphenylenecarbonyl).

Cross-link property has been used to improve the insolubility, mechanical strength, stiffness, and rigidity of polymer microbeads having potential applications in solid-phase synthesis, solid-phase extraction, and biomedical fields. Therefore synthesis of polymer with desired cross-linker (hydrophilic/hydrophobic/rigid/flexible) and concentration of cross-linker (cross-link density) is an important. In the present review, chemical cross-linking by free-radical, condensation, UV radiation, and small-molecule cross-linking are discussed in details. Further, effects of cross-linker (type/concentration) on polymer properties like surface area, pore volume, pore size, particle size, thermal degradation, glass transition temperature, and polymer swelling are also discussed. Importantly, present review discusses the influences of rigidity, flexibility, hydrophilicity, and hydrophobicity of a cross-linker on polymer properties.

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