Effect of polymer properties on poly(vinylidene fluoride) particles produced by rapid expansion of CO2+polymer mixtures

Polymorphic properties of micronized mefenamic acid, nabumetone, paracetamol and tolbutamide produced by rapid expansion of supercritical solutions (RESS)

“…For off-line analysis of the produced particles samples are collected on a membrane filter (L). A more detailed description of the RESS apparatus and the experimental procedure can be found elsewhere in literature [43,[68][69][70][71][72]]. …”

Crystal phase transformation of α into β phase poly(vinylidene fluoride) via particle formation caused by rapid expansion of supercritical solutions

“…[19][20][21][22][23][24] PVDF is commonly produced by emulsion polymerization, which is associated with large quantities of waste water, the need for uorinated stabilizers and substantial amounts of energy for polymer drying. [38][39][40] For example, PVDF processing in scCO 2 aiming for the modication of certain polymer properties is not investigated in detail, yet. In recent years, the synthesis of polymers in supercritical carbon dioxide (scCO 2 ) has gained attention due to many advantages of the solvent: CO 2 is considered to be environmentally benign, is further a non-ammable, chemically inert, inexpensive and non-toxic solvent, which allows processing at moderate conditions (T C ¼ 304.13 K, p C ¼ 7.38 MPa) in addition to unproblematic solvent separation.…”

“…25,26 Therefore, alternate polymerization strategies are considered. 40 The emphasis was on the inuence of polymer properties such as molar mass, polymer end groups and degree of crystallinity on the obtained particle size. [27][28][29] The homogeneous phase polymerization of uorinated monomers in scCO 2 was reported in 1992 and was followed by the synthesis of PVDF.…”

“…In recent years, the synthesis of polymers in supercritical carbon dioxide (scCO 2 ) has gained attention due to many advantages of the solvent: CO 2 is considered to be environmentally benign, is further a non-ammable, chemically inert, inexpensive and non-toxic solvent, which allows processing at moderate conditions (T C ¼ 304.13 K, p C ¼ 7.38 MPa) in addition to unproblematic solvent separation. 40 In this contribution we describe the impact of RESS on PVDF properties for a model polymer with a number average molar mass of M n ¼ 2000 g mol À1 . [30][31][32][33][34] In addition to polymerization under supercritical conditions, even the production of semiconducting polymer particles has been reported in scCO 2 .…”

Homogeneous Phase Copolymerizations of Vinylidene Fluoride and Hexafluoropropene in Supercritical Carbon Dioxide

“…Previously, it was shown that PVDF nanoparticles may be obtained via rapid expansion from supercritical solution. [45] …”