Crosslinked Poly(2-oxazoline)s as “Green” Materials for Electronic Applications

Abstract

Poly(2-nonyl-2-oxazoline) 80 -stat-poly(2-dec-9 1 -enyl-2-oxazoline) 20 and poly(2-dec-9 1 -enyl-2-oxazoline) 100 can be synthesized from the cationic ring-opening polymerization of monomers that can be derived from fatty acids from renewable resources. These (co)poly(2-oxazoline)s can be crosslinked with di-and trifunctional mercapto compounds using the UV-induced thiol-ene reaction. The complex permittivity of the corresponding networks increases with the temperature and decreases with the network density. In a frequency range from 10´2 to 10 6 Hz and at temperatures ranging from´20 to 40˝C, the changes of the real part of the complex permittivity as well as the loss factor can be explained by interfacial polarization within the material. At a temperature of 20˝C and a frequency of 50 Hz, the permittivity of the crosslinked (co)poly(2-oxazoline)s covers a range from 4.29 to 4.97, and the loss factors are in the range from 0.030 to 0.093. The electrical conductivities of these polymer networks span a range from 5ˆ10´1 2 to 8ˆ10´9 S/m, classifying these materials as medium insulators. Notably, the values for the permittivity, loss factor and conductivity of these copoly(2-oxazoline)s are in the same range as for polyamides, and, hence, these copoly(2-oxazoline)-based networks may be referred to as "green" alternatives for polyamides as insulators in electronic applications.

Synthesis and Investigation of Thermo-Induced Gelation of Partially Cross-Linked Poly-2-isopropyl-2-oxazoline in Aqueous Media

“…Briefly, the mixture of adipodinitrile (11 g, 0.1 mol), 2-aminoethanol (13.5 g, 0.22 mol), and Cd(OCOCH 3 ) 2 (2.3 g, 0.01 mol) was heated at 140 • C for 24 h. The target product was distilled, dried over sodium and redistilled. The yield was 10. multifunctional cross-linker [17][18][19][20] and oligo-and polyoxazoline chain cross-linking [21][22][23][24][25][26]. The hydrogels described in literature are characterized by high affinities for water and swelling degrees.…”

“…Polyoxazoline-based gels have great prospects to be used in biomedical applications due to the nontoxicity and biocompatibility of these polymers [9,15,16]. In general, there are two routes to cross-linked polyoxazoline production, which are the simultaneous copolymerization of monomers with a multifunctional cross-linker [17][18][19][20] and oligo-and polyoxazoline chain cross-linking [21][22][23][24][25][26]. The hydrogels described in literature are characterized by high affinities for water and swelling degrees.…”

Investigation of the swelling behavior of hydrogels derived from high‐molecular‐weight poly(2‐ethyl‐2‐oxazoline)

“…However, POx‐based hydrogels have been found to show no sharp phase transition, but to transit from a highly to a lowly swollen state due to a change of the swelling–deswelling rate d S /d T over a broad temperature range . Such POx‐hydrogels are prepared by end‐group linking, simultaneous copolymerization of a monomer with a multifunctional cross‐linker, or only using a radical starter and a multifunctional cross‐linker …”

Enhancement of the Insulation Properties of Poly(2‐oxazoline)‐co‐Polyester Networks by the Addition of Nanofillers

“…Epoxy resins, polyesters, and polyamides constitute the polymer classes commonly used for the fabrication of electrical equipment insulation . While poly(2‐oxazoline)s, which are known for their high temperature stability, may be referred to as “pseudo”‐polyamides (due to the fact that the amide bond is situated in the side‐chain, but not within the main chain), a precedent initial study was conducted to investigate the dielectric properties of this polymer class . It was found that densely crosslinked poly(2‐oxazoline)s exhibited the same ranges of permittivity, loss factor, and conductivity like polyamides commonly used in high‐voltage applications as, e.g., insulating thermoplasts and for the enhancement of partial discharge resistance in composites .…”