Gas permeability of thin dense films from polymer blend of thermoplastic elastomer and polyolefin

Abstract

Stretched thin films composed of a thermoplastic elastomer, a polystyrene-block-poly(ethylene butylene)-block-polystyrene triblock copolymer (SEBS), and polyolefins, poly(ethylene-co-ethylacrylate) and poly(ethylene-co-propylene), were obtained by blow-molding, uniaxial stretching, and cooling to room temperature and the gas permeability of the stretched films was investigated. When the as-blown annealed film was subjected to uniaxial stretching in the machine direction, P O2 and P N2 increased with an increase in the stretching ratio K and approached a constant value at high stretching ratios. In addition, P O2 /P N2 decreased gradually with K and approached a value of 2.95-3.0. The reason for this unique gas permeation behavior is that the molecular mobility of poly(ethylene butylene) chains in a direction normal to the film increases and reaches an equilibrium state at around K 5 4.5. The change in gas permeability of the stretched films can be explained using a deformation model for the SEBS matrix.

Accurate Evaluation of Hepatocyte Metabolisms on a Noble Oxygen-Permeable Material With Low Sorption Characteristics

“…Although many thermoplastics have been reported for cell culture, factors such an environment cannot be achieved according to their poor oxygen permeability ( Gencturk et al, 2017 ). Even in “gas-permeable” thermoplastic elastomers (TPEs), such as a polystyrene- block -poly (ethylene butylene)- block -polystyrene triblock copolymer (SEBS) ( Campbell et al, 2021 ; Schneider et al, 2021 ), the oxygen permeability is still not sufficient [22 of SEBS vs. 800 of PDMS; unit: × 10 –10 cm 3 (STP) cm cm −2 s −1 (cmHg) −1 ] to induce such metabolic phenotypes ( Merkel et al, 2000 ; Uenishi et al, 2014 ). Together, it demonstrates the capability of PMP as an alternative to PDMS in regard to oxygen permeable materials.…”

“…As the results described previously clearly demonstrated, high oxygen permeability and low sorption characteristics of PMP successfully improved the quality of cultured primary hepatocytes and the accuracy of evaluation of hepatocyte metabolisms. While oxygen permeabilities are very low ( Merkel et al, 2000 ; Uenishi et al, 2014 ), other thermoplastic elastomers and thermoplastics with less sorption characteristics than PDMS have been reported ( Gencturk et al, 2017 ; Schneider et al, 2021 ). They are also promising alternatives to PDMS, and thus, an appropriate selection of materials seems important depending on the context of use ( Campbell et al, 2021 ).…”

Elastomers for the 21st century

“…This can be accomplished through the typical sulfur vulcanization used to create rubber tires, but also to produce novel high‐performance elastomers as in the work by http://onlinelibrary.wiley.com/doi/10.1002/app.38201/full1 Alternatively, different types of vulcanizing agents can be explored, as in the article by http://onlinelibrary.wiley.com/doi/10.1002/app.38471/full 2. Deformation of elastomers can also lead to novel fabrication techniques, as described by http://onlinelibrary.wiley.com/doi/10.1002/app.38379/full 3…”