Formation of polyketone particle structure by hexafluoroisopropanol solvent evaporation and effects of plasticizer addition

Abstract

Few solvents are capable of dissolving polyketones (PKs). 1,1,1,3,3,3-Hexafluoro-2-propanol (hexafluoroisopropanol, HFIP) is a better solvent than trifluoroethanol and m-cresol. When HFIP was evaporated from a PK/HFIP solution, a porous cast-film with a microparticle structure was formed because the isotactic PKs adopted a helical conformation, and convection during evaporation of the high polarity and lowboiling-point HFIP caused aggregation and rolling of the polymer molecules. The addition of plasticizer suppressed particle formation, improving the surface structure and mechanical properties of the film. In particular, the dielectric properties of the film improved significantly. This will enable PKs, which are rigid insulating materials, to be used as dielectric materials, broadening their range of applications.

Preparation and characterization of novel transparent plasticized poly(butylene terephthalate)-co -poly(alkylene glycol terephthalate) gel

“…This is because the crystalline polymer molecules are attracted by highly polar, low-boiling-point solvents such as HFIP, and easily form strong convection cells during evaporation. 24 The PBT-co-PAGT film also shows a particle structure; the particle surfaces are not smooth and the particle size is about /5-20 mm, much smaller than those in the PBT film. The block thermoplastic copolymer has crystalline hard segments and amorphous soft segments, the head and tail of hard segments are connected to the soft segments and these segments combine together and restrict each other.…”

“…A large number of spherical particles (∼ ϕ 100 µm) are connected randomly from the surface to the bottom to form a porous PBT film. This is because the crystalline polymer molecules are attracted by highly polar, low‐boiling‐point solvents such as HFIP, and easily form strong convection cells during evaporation . The PBT‐ co ‐PAGT film also shows a particle structure; the particle surfaces are not smooth and the particle size is about ϕ 5–20 µm, much smaller than those in the PBT film.…”

“…Thus using the semicrystalline polymer to make a gel will be a valuable way. For semicrystalline polymers such as polyketones, poly(ethylene terephthalate), and polyamides (including PBT), it is difficult for the plasticizer to completely inhibit the formation of particle‐like structures in cast film, so the films are opaque and have low toughness; this limits their applications, particularly in optical electronics. Here, we made a new transparent polymer gel using a poly(butylene terephthalate)‐ co ‐poly(alkylene glycol terephthalate) (PBT‐ co ‐PAGT) copolymer and a plasticizer, dibutyl adipate (DBA).…”

Electrically Triggered Actuation of Plasticized Thermoplastic Polyurethane Gels

“…Plasticized gels are therefore ideal soft actuator materials for biomedical applications. In our previous studies, we prepared plasticized gels from various plastic polymers, including poly(vinyl chloride), poly(vinyl alcohol), polyketones, and poly(butylene terephthalate) copolymers . Some plasticized gels have been developed for use as actuators in microfingers, for rolling and contractile operations, and for variable focal length lenses .…”