Effect of stretching on structure and properties of polyethylene hollow fiber membranes made by melt‐spinning and stretching process

Abstract

Microporous polyethylene (PE) hollow fiber membrane was prepared by the melt-spinning and stretching (MS-S) method. The effect of stretching on the structure and properties of the membrane was investigated by water contact angle measurement, field emission scanning electron microscopy (FESEM), mercury porosimetry, and N 2 permeation. The tensile experiment was used to study the hard elasticity and the mechanical properties of annealed PE fibers. During the stretching process, the stretching temperature, rate, and ratio have great effects on the morphology, crystal structure, pore structure, and N 2 permeation of the membrane. Experimental results showed that N 2 permeation and porosity of the membrane increased with the increase in stretching temperature, rate, and ratio. The pore size decreased with increase in the stretching rate and increased with the stretching ratio. The pore size distribution was also affected by the stretching process, and was investigated in detail.

A Review on Porous Polymeric Membrane Preparation. Part II: Production Techniques with Polyethylene, Polydimethylsiloxane, Polypropylene, Polyimide, and Polytetrafluoroethylene

“…To commercialize the membranes and increase the water flux [20], changes to the membranes configuration was proposed by the Mitsubishi Rayon Corporation in 1977 [96]. The MSCS technique to fabricate hollow fiber membranes was developed, and these microporous membranes gained popularity by being used in several applications such as blood oxygenators, desalination equipments, biosensors, ultra-pure water purifiers, and membrane distillators [20,22,96,97,98].…”

“…As a result, the micropores are formed in the membranes. This means that the effect of external forces is the main origin for the porous structure formation [20,22].…”

“…Thus, the MSCS process is more environmentally friendly, since MSCS only uses a neat polymer. This also means that there is no phase separation, and its control is relatively easy [20,22].…”

Interconnected, microporous hollow fibers for tissue engineering: Commercially relevant, industry standard scale‐up manufacturing

“…Micropores allow a diffusion path for nutrients into the scaffold and removal of cellular waste products. Micropores can be created after the spinning process via cold stretching, thermally induced phase separation (TIPS), or by introducing a secondary sacrificial component into the base polymer . Subsequent removal of the sacrificial component leaves a microporous network throughout the fiber wall generated by the primary polymer.…”

“…Several methodologies to form micropores are described in published literature and patents. These include the addition of soluble additives, thermally induced phase separation, and melt spinning cold stretching …”