“Green” environmental crazing of polymers in oil-in-water emulsions with high water content

Bakirov

J of Applied Polymer Sci

et al. 2022

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.

Section: Resultsmentioning

confidence: 99%

Section: Preparation Of Pp-peo Nanocomposites Via Ecmentioning

confidence: 99%

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

Bakirov

J of Applied Polymer Sci

et al. 2022

“…Preparation of mechanoresponsive materials with hard elastic properties based on semicrystalline polymers involves the stages of environmental intercrystallite crazing (EIC) and subsequent spontaneous strain recovery (SSR). Figure illustrates the general scenario of this process. − …”

Section: Resultsmentioning

confidence: 99%

“…Adsorption measurements of the samples were performed with an ASAP 2020 automatic analyzer (Micromeritics). Prior to measurements, all samples were evacuated for 4–5 h. Pore dimensions were estimated according to the Barrett–Joyner–Halenda (BJH) method using Micromeritics software …”

Section: Methodsmentioning

confidence: 99%

Mechanoresponsive Hard Elastic Materials Based on Semicrystalline Polymers: From Preparation to Applied Properties

Аржакова

Долгова

ACS Appl. Polym. Mater.

et al. 2020

Self Cite

This work offers an alternative strategy for the preparation of hard elastic (HE) materials via environmental intercrystallite crazing and subsequent spontaneous strain recovery. Structure and properties of HE materials are characterized: secondary loading in air is accompanied by the development of porosity (up to 40%) with pores below 20 nm; upon unloading, the as-opened porous structure is closed in the elastic manner (strain recovery up to 90%). Upon loading/unloading cycles, the HE samples behave as "living" mechanoresponsive materials with openable and closable mesopores. This strategy has proved to be universal for diverse semicrystalline polymers [high-density polyethylene, polypropylene, poly(tetrafluoroethylene)]. The phenomenon of the forced impregnation of polymer matrixes with target cargo upon cyclic loading offers benefits for the incorporation of diverse additives when the overall uptake can be increased by 500%. The mechanism behind this phenomenon is discussed. Practical benefits of HE polymers and related nanocomposites as applied materials (including antibacterial and photoactive materials) are highlighted.

“…Polyolefin (HDPE and UHMWPE) films were used to prepare the mesoporous polymer matrices via the intercrystallite crazing in the presence of two-phase oilin-water emulsions with high water content as an efficient alternative to organic solvents [17]. n-Heptane was used as the organic component of the emulsion.…”

Section: Doi: 101134/s1070363221110104mentioning

confidence: 99%

Biomedical Organic-Inorganic Nanocomposite Materials Based on High-Density Polyethylene and Ultra-High-Molecular-Weight Polyethylene and Silver Nanoparticles

et al. 2021

Self Cite

Organic-inorganic nanocomposite materials based on high-density polyethylene and ultra-high-molecular weight polyethylene have been prepared via different methods of silver ions reduction to silver within confined space. The resultant materials have revealed uniform distribution of silver nanoparticles, and their size has been controlled by the reduction method. Silver nanoparticles with high surface/volume ratio have been obtained under mild conditions of reduction. Silver-containing nanocomposites have shown high antibacterial activity and can be used as efficient materials for biomedical purposes.