Unique structure and new thermophysical properties of poly(ethylene oxide) in nanocomposites based on nanoporous polypropylene matrices

Abstract

Polypropylene (PP)−poly(ethylene oxide) (PEO) nanocomposites were prepared by tensile drawing of PP films in water–ethanol solutions containing PEO with molecular masses of 4, 20, and 200 kDa via environmental crazing (EC). EC of PP films is accompanied by the development of nanoporous structure, which is loaded with the PEO component. The content of PEO in the PP − PEO nanocomposites can achieve 40%. Crystallization of PEO within the nanoporous PP matrix proceeds under the conditions of the confined space: as a result, the degree of crystallinity and melting temperature of PEO are markedly reduced. This effect appears to be more pronounced as the molecular mass of PEO increases. The direction of orientation of the PEO crystalline lamellae also depends on the molecular mass of PEO. The prepared PP‐PEO composites with new thermophysical properties of PEO can be used as gas‐separation membranes as well as in microelectronics and electrochemical devices.

Functionalization and Surface Modification of Mesoporous Hydrophobic Membranes by Oligomers and Target Additives via Environmental Crazing

“…PEG and PPG as oligomers are widely used in the pharmaceutical and food industry. The use of ecologically safe hydrophilic PEG and PPG as PALEs can promote environmental crazing in “green” mode and provide surface modification and hydrophilization of hydrophobic PP, HDPE, and PET whereas low-molecular-mass and high-molecular-mass compounds are able to penetrate the mesoporous structure of polymers upon crazing [ 26 , 27 , 28 ]. This work presents the study on the potential of environmental crazing as the strategy for the preparation of multicomponent membranes materials that synergetically unite the functional properties of incorporated additives and porous host matrix: membrane performance, vapor permeability, selectivity, hydrophilicity, antibacterial and sensing properties as well high mechanical robustness.…”