Polyesters development

Sucrose polyesters, which are made by esterilying sucrose with long-chain fatty acids, have the physical properties of fat, but are resistant to digestive enzymes (40). Olestra, a sucrose polyester developed by Procter Gamble, was submitted for regulatory approval in May 1987. In order to faciUtate the approval process, Procter Gamble has since narrowed the scope of its food additive petition to include olestra s use only in savory and extmded snacks. 

PBT resin has been reviewed in many articles, often as part of a larger review of polyesters [1-3], A recent article provides an historic account of polyester development as an alternative to nylon fibers [4], while the review of Kirsch and Williams in 1994 gives a business perspective on polyesters [5], However, an understanding of PBT in the context of the more common polyester polyethylene terephthalate) (PET) is often overlooked. PET dominates the large volume arenas... 

In particular, during the course of commercial polyester development it turned out that the use of highly purified raw materials is of paramount importance. In this respect the same principles apply to laboratory-scale chemical synthesis as those that apply to industrial-scale manufacturing. Polyester syntheses, like most... 

Zimmermann, H., Degradation and Stabilization of polyesters. Developments in Polymer Degradation, Grassie, N., Ed. Applied Science Publishers, Vol. 5, London, 1984. 

Figure 5.8 Mylar, a polyester developed by E. I. DuPont deNemours Co., was used to cover the wings and pilots compartment of the Gossamer Albatross, the first human-powered aircraft to fly across the English Channel.

The data on aromatic polyesters based on phthalic and -oxybenzoic acid derivatives have been presented and various methods of synthesis of such polyesters developed by scientists from different countries for last 50 years have been reviewed. 

Attempts had been made to synthesise polyesters based on phthalic acid as the diacid component, but these products were amorphous, had low softening points, and were rapidly attacked by organic solvents and acids and bases. Research into polyesters made by the reaction of terephthalic acid (or esters thereof) with aliphatic diols, led to the discovery of polyesters of high commercial value poly(alkylene terephthalate)s [4]. This pairing of diols with terephthalic acid eventually led to the most commercially successful aromatic polyesters, but other synthetic pathways were also investigated towards such products in the early days of polyester development. These included the self-condensation of hydroxy acids of the structure -H0-R-Ph-C02H, where R-OH is para to the acid group and R is -(CH2)- or -(CH2)2- [5], and reactions of aliphatic diacids with 1,4-dihydroxy benzene and similar aromatic diols [6, 7]. Also synthesised about the same time were polyesters based on C2-Cg aliphatic diols and any of the isomeric naphthalene dicarboxylic acids [8]. 

A large variety of hyperbranched polymers with acrylate, vinyl ether, allyl ether, or epoxy functions were studied as multifunctional cross-linkers in coatings and in thermosets, using thermal as well as UV curing methods Clearly, polyesters are most prominent in the field, with the Perstorp Boltom products leading in technical studies. The commercialized poly(esteramide)s from DSM, sold under the trade name Hybrane polyethylenimines from BASF AG, available under the trade name TupasoF and poly(urethane)s (PUs) and polyesters developed by BASF are examples for hyperbranched polymers suited for coatings and resin products. 

Hydiaspun technology patented by Ahlstrom and Ecoflex- a fiilly biodegradable, compostable polyest developed by BASF are just two exanqiles of a number of biod radable products available on Ae market. 

H. Zimmmnann, Degradation and stabiUsation of polyesters. Developments in Polymer Degradatum-5, Chapter 3, N. Grassie (Ed.), AppUed Science PubUshers, London (1984). 

The first polyester, developed in the 1940s, involved the polymerization of benzene 1,4-dicarboxylic acid (terephthalic acid) with 1,2-ethanediol (ethylene glycol) to give poly-(ethylene terephthalate), abbreviated PET. Virtually aU PET is now made from the dimethyl ester of terephthahc acid by the following transesterification reaction (Section 14.4C) ... 

A special class of unsaturated polyesters, developed for composite applications in corrosive environments, is the so-called vinyl esters and vinyl ester urethane resins. 

Because the polyamides and the polyesters developed for fibers are too high-melting and too fast-setting to be used for adhesives, chemists have made copolymers to lower the melt point and increase the set time of these two classes of polymers. Today most of the polyamides and polyesters used in hot melt adhesives are based either on monomers not used for fibers or, more... 

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