A Survey of Some Recent Advances in Step-Growth Polymerization

Abstract

The field of step-growth polymers encompasses many polymer structures and polymerization reaction types. This chapter attempts to cover topics in step--growth polymerization outside of the areas reviewed in the other introductory chapters in this book, i.e., poly(aryl ethers), dendritic polymers, high--temperature polymers and transition-metal catalyzed polymerizations. Polyamides, polyesters, polycarbonates, poly(phenylene sulfides) and other important polymer systems are addressed. The chapter is not a comprehensive review but rather an overview of some of the more interesting recent research results reported for these step-growth polymers, including new polymerization chemistries and mechanistic studies. Aromatic PolyamidesAromatic polyamides (aramids) are important in the commercial fibers industry because of their high tensile strength and good flame resistance. The demand for these materials is increasing as new applications are found. One example is their use in composites where high-use temperatures, light weight, chemical resistance, and dimensional stability are crucial.The most widely employed synthetic route to aramids is based on the polycondensation of dicarboxylic acids with diamines in the presence of condensing agents. Good reviews on the synthesis of aramids have recently appeared (1-3). Recently, promising alternative synthetic routes to aramids have been reported and are described herein.These include the polycondensation of N-silylated diamines with diacid chlorides, the addition--elimination reaction of dicarboxylic acids with diisocyanates, and the palladium-catalyzed carbonylation polymerization of aromatic dibromides, aromatic diamines and carbon monoxide.The synthesis of aramids from N-silylated amines has been employed because N-silylated aromatic amines show higher reactivity relative to the parent diamines and the resulting trialkylsilyl halide does not lower the reactivity of unreacted amine functionality as is the case with amine protonation

Synthesis and characterization of a biphenyl perfluorocyclobutyl (BP‐PFCB) polyethylene glycol (PEG) blend compatibilizer

“…Although these properties are highly desirable, the majority of these materials have high melt transitions (T m s) resulting in poor processability. [1][2][3] Semifluorinated poly aryl ethers are an emerging class of thermoplastics that maintain high thermooxidative stability while often exhibiting solution and melt processability. [4,5] Recent advancements included semifluorinated poly(aryl ether)s prepared with a quadrephenyls, [6] segmented with oligo(ethylene glycol)s, [7] perfluorocyclopentenyl, [8] and trifluoromethyl groups.…”

Poly(arylene ether)s Containing 1,2,4-Triazole and Phthalimide or Naphthalimide Moieties Joined by a N−N Linkage

“…Poly(arylene ether)s are an important class of engineering thermoplastics and possess useful physical properties such as high modulus, toughness, high thermal, thermooxidative stability, and chemical resistance. − These polymers have become increasingly important and are used in a variety of applications such as coatings, adhesives, composites, and molded components. ,, …”

“…Poly(arylene ether)s are an important class of engineering thermoplastics and possess useful physical properties such as high modulus, toughness, high thermal, thermooxidative stability, and chemical resistance. [1][2][3] These polymers have become increasingly important and are used in a variety of applications such as coatings, adhesives, composites, and molded components. 1,2,4 Earlier work in this laboratory demonstrated the synthesis of high molecular weight poly(ether imide)s and copoly(ether imide)s having a N-N linkage between the imide units in the polymer backbone.…”