Polymer specialty monomers

This book is a conq)endmm of refereed papers based on invited talks presented at the American Chemical Society (ACS) Symposium on Sp ialty Monomers and Their Polymers. Specialty monomers are inherently different from commodity monomers, and it is these differences that result in new and important polymer properties. The most versatile feature of specialty iiKjnomers and polymers is their built-in functionality. This ftinctionality offers significant opportunity to customize the design of polyn rs to m t specific performance, physical, and chemical properties. These properties are needed for many of today s hi-tech applications and cannot be easily obtained with more common commodity monomers and polymers. 

AH the common monobasic (107) and dibasic esters (108) of tetrahydrofurfuryl alcohol have been prepared by conventional techniques the dibasic esters and some of the mono esters are effective as primary or secondary plasticizers for vinyl polymers. Tetrahydrofurfuryl acrylate [2399-48-6] and methacrjiate [2455-24-5] specialty monomers, have been produced by carbonylation (nickel carbonyl and acetylene) of the alcohol (109) as weU as by direct esterification (110—112) and ester interchange (111). 

Itaconic acid is a specialty monomer that affords performance advantages to certain polymeric coatings (qv) (see Polyesters, unsaturated). Emulsion stabihty, flow properties of the formulated coating, and adhesion to substrates are improved by the acid. Acrylonitrile fibers with low levels of the acid comonomer exhibit improved dye receptivity which allows mote efficient dyeing to deeper shades (see Acrylonitrile polymers Fibers, acrylic) (10,11). Itaconic acid has also been incorporated in PAN precursors of carbon and graphite fibers (qv) and into ethylene ionomers (qv) (12). 

Divinylbenzene. This is a specialty monomer used primarily to make cross-linked polystyrene resins. Pure divinylbenzene (DVB) monomer is highly reactive polymericaHy and is impractical to produce and store. Commercial DVB monomer (76—79) is generally manufactured and suppHed as mixtures of m- and -divinylbenzenes and ethylvinylbenzenes. DVB products are designated by commercial grades in accordance with the divinylbenzene content. Physical properties of DVB-22 and DVB-55 are shown in Table 10. Typical analyses of DVB-22 and DVB-55 are shown in Table 11. Divinylbenzene [1321 -74-0] is readily polymerized to give britde insoluble polymers even at ambient temperatures. The product is heavily inhibited with TBC and sulfur to minimize polymerization and oxidation. 

A large number of compounds related to styrene have been reported in the literature, Those having the vinyl group CH2=CH—attached to the aromatic ring are referred to as styienic monomers, Several of them have been used for manufacturing small-volume specialty polymers. The specialty styreme monomers that arc manufactured in commercial quantities arc vinyl toluene, /r, -methylstyrene, or-methylstyrene. and divinylbenzene. In addition, 4-fert-butylstyrene (TBS) is a specialty monomer that is superior to vinyltoluene and pnra-methylstyrene in many applications. Other styrenic monomers produced in small quantities include chlorostyrene and vinylbenzene chloride. With the exception of a-methylstyrene, which is a by-product of the phenol-acetone process, these specialty monomers are more difficult and expensive to manufacture than styrene... 

Performance Chemicals, specialty chemicals (surfactants, synthetic oils, rubbers specialty monomers) and emulsion polymers based on latex Agricultural Products herbicides and seeds ... 

Next-generation soft contact lenses, dental polymers, surface coatings, and similar materials are produced from compounds of varying structure and reactive functionality. For example, currently in development are new soft lenses that will be manufactured from monomers synthesized with dimethylsil-oxane backbones. The dimethylsiloxane backbone is terminated with a methacryloxy functionality that supplies the site for polymerization. The siloxane provides lens softness. Occasionally the functionality is formed on both ends of the monomer, resulting in undesired properties. The compound BisGMA is a monomer that is polymerized to form hard dental structures. In the monomer synthesis process impurities are coproduced that interfere with the polymerization. Finally, diacetone acrylamide used in a copolymerization process is another specialty monomer that is occasionally contaminated with difficult-to-remove impurities. These three monomers are quite reactive at modest temperature and cannot be purified by distillation. The three examples that are presented here derive from as yet unpublished research (Krukonis, 1982c). 

The compositions of most acrylic and styrene-acrylic emulsion polymers contain from one to three principal building-block monomers (which generally make up over 90% by weight of the backbone) and one or more of the auxiliary or specialty monomers. The building-block monomers mainly determine the hardness (Tg) and hydrophobicity of the polymer. Styrene and the acrylic monomers form amorphous, random copolymers with a Tg that is roughly proportional to the weight fractions and Tg s of the component monomers. Several mathematical equations have been proposed to describe correlations between Tg s and copolymer composition. Perhaps the most well known is the Fox equation [28] ... 

Eastman Chemical Co, Polymer Additives and Specialty Monomers Business Unit. PO Box 431. Kingsport, TN 37662, USA tel +1-615-229-2000 fax +1-615-224-0648... 

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