Gel spinning of porous poly(methyl methacrylate) fibres

Abstract

Solutions of poly(methyl methacrylate) in 1-butanol demix on cooling. By solution extrusion, fibres are produced which have an oriented porosity. The relation between this morphology, the phase diagram and the extrusion procedure is discussed.

Phase Transitions in Swollen Networks. 3. Swelling Behavior of Radiation Cross-Linked Poly(vinyl methyl ether) in Water

“…Such a g−g demixing can be studied by different techniques. One of them is calorimetry, and this possibility has been discussed in the literature. , The technique has been applied with success to different polymer solvent systems − and more particularly to the system linear PVME/water . The obtained experimental data revealed the occurrence of type III demixing behavior.…”

The Effect of Stretch on Multi-Pore-Structure of Ultrahigh Molecular Weight Polyethylene/SiO 2 Hybrid Hollow Fiber Membranes

“…For spinning, a spinneret with an outer diameter of 10.5 mm and an inner tube diameter of 7.8 mm was used. The fibers were spun by the gel-spinning process (airgap = 15 cm) [16]. The temperature was 20 4 C and the relative humidity was 65%.…”

Phase behaviour and solvent diffusion in the system poly(methyl methacrylate)/methanol

“…The use of DSC in the investigation of L-L demixing has been well discussed in the literature 9) and has been applied to several polymer-solvent systems [1][2][3][4][5] . In this work, the solutions are prepared by heating the solvent together with the polymer in the sample pans to a temperature above 100 8C.…”

“…Aliphatic alcohols is are poor solvents for atactic poly-(methyl methacrylate) (aPMMA) and liquid-liquid demixing (L-L demixing) from the homogeneous solution takes place at temperatures far above room temperature. A typical example is the system aPMMA/butanol with a maximum in the demixing curve at a temperature of around 80 8C 1,2) . The exact position of this demixing curve on the temperature scale depends on the molecular mass of the polymer and its distribution.…”

“…Such a macroscopic demixing process, however, is slow and cooling to room temperature can freeze the above mentioned metastable structure because of the vitrification of the concentrated domains. A vitrification results from the intersection of the demixing curve with the glass transition (T g )-concentration relationship [1][2][3][4][5] . The glass transition temperature of these concentrated domains corresponds to this intersection temperature and will remain constant under the miscibility gap if the polymer is monodisperse.…”