A study of cryostructuring of polymer systems. 34. Poly(vinyl alcohol) composite cryogels filled with microparticles of polymer dispersion

摘要: Macroporous filled and unfilled poly(vinyl alcohol) (PVA) cryogels are produced by cryogenic treatment (freezing at −20°C for 12 h followed thawing a rate of 0.03°C/min) mixtures an aqueous PVA solution full-component acetate) (PVAc) dispersion or its individual components. The values the elasticity modulus fusion temperature determined obtained samples; their microstructure is studied light microscopy thin sections. It shown that effects induced incorporation PVAc into macroporous matrix cryogel due to presence both discrete phase, i.e., solid microparticles, ingredients liquid phase dispersion, mainly, urea. Therewith, dispersed particles themselves serve as reinforcing filler, increase rigidity (to lesser extent) heat endurance cryogel, while urea, which possesses chaotropic properties hinders intermolecular hydrogen bonding chains, reduces composites. As result, total effect competition differently directed influences these components depends on concentration in resulting cryogel. also microparticles mainly entrapped gel form necklacelike aggregates, cross-sectional areas lengths depend degree composite filling.