Ethylene glycol polyurethanes from

Polyester and polyether diols are used with MDI in the manufacture of thermoplastic polyurethane elastomers (TPU). The polyester diols are obtained from adipic acid and diols, such as ethylene glycol, 1,4-butanediol, or 1,6-hexanediol. The preferred molecular weights are 1,000 to 2,000, and low acid numbers are essential to ensure optimal hydrolytic stabihty. Also, caprolactone-derived diols and polycarbonate diols are used. Polyether diols are... 

Fatty acids, both saturated and unsaturated, have found a variety of applications. Brassilic acid (1,11-un-decanedicarboxylic acid [BA]), an important monomer used in many polymer applications, is prepared from erucic acid (Scheme 2), obtained from rapeseed and crambe abyssinica oils by ozonolysis and oxidative cleavage [127]. For example, an oligomer of BA with 1,3-butane diol-lauric acid system is an effective plasticizer for polyvinylchloride. Polyester-based polyurethane elastomers are prepared from BA by condensing with ethylene glycol-propylene glycol. Polyamides based on BA are known to impart moisture resistance. 

Molded urethanes are used in items such as bumpers, steering wheels, instrument panels, and body panels. Elastomers from polyurethanes are characterized by toughness and resistance to oils, oxidation, and abrasion. They are produced using short-chain polyols such as polytetram-ethylene glycol from 1,4-butanediol. Polyurethanes are also used to produce fibers. Spandex (trade name) is a copolymer of polyurethane (85%) and polyesters. 

The top layer was washed with water and ethylene glycol and dried to give 135 g of a yellow oily material that from infrared spectral analysis was identified to be the same triol used to prepare the flexible polyurethane foam. 

Figure 25.3 b) shows a generic polyester-based polyurethane. The most common polyester repeat units are derived from the polycondensation of adipic acid and a diol, such as ethylene glycol, which results in the structure shown in Fig, 25.4. The average molecular weight of the polyester sequences between urethane links commonly ranges between 400 and 6,000 g/mol. 

Several polymer-related uses of brassylic acid (BA) have been investigated. For example, a BA/l,3-butanediol/lauric acid oligomer is an effective plasticizer for poljrvinyl chloride,[6] BA/ethylene glycol and BA/propylene glycol polymers function as polyester based polyurethane elastomers,[7] and BA has been patented as a cross-linker for glycidyl methacrylate copolymer powder coatings.[8] However, the most detailed studies have involved polyamides selected data from these studies are summarized in Table I. 

Problem 16.56 Indicate the reactions involved and show the structures of the following condensation polymers obtained from the indicated reactants (a) Nylon 66 from adipic acid and hexamethylene diamine (b) Nylon 6 from e-caprolactam (c) Dacron from methyl terephthalate and ethylene glycol (d) Glyptal from glycerol and terephthalic acid (e) polyurethane from diisocyanates and ethylene glycol. ... 

Adipic acid can also polymerize with alcohols such as ethylene glycol to form polyesters, which can combine with isocyanates to form polyurethanes. Smaller esters of adipic acid produced with alcohols in the C-8 to C-10 range are called adipates. These are used as softeners in plastic (such as polyvinyl chloride) and as synthetic grease base oils. Adipic acid is also used in the food industry. Food grade adipic acid is prepared synthetically or extracted from beet juice as a natural source. It is used as a gelling agent, as an acidulant to provide tartness, and as a preservative. 

Methyl a-D-glucopyranoside is the only product of commercial promise to have thus far emerged from work with protic solvents it has utility in the preparation of polyurethane foams. Mehltretter and coworkers125,126 have described the application of mixtures of D-glucosides obtained by the acid-catalyzed reaction of ethylene glycol, 1,2-propanediol ( propylene glycol ), or glycerol with starch,... 

Dimethyl terephthalate for the production of polyethylene terephthalate) is produced by the cobalt salt-catalyzed oxidation of p-xylene with oxygen (reaction 1.15).209 In this free radical process, some biphenyl derivatives are formed. In addition, triesters are formed from any trimethylbenzenes in the feed. Thus, the still bottoms contain several compounds, which are all methyl esters. Hercules found that transesterification of this mixture with ethylene glycol led to a mixture of polyols that could be used with isocyanates to form rigid polyurethanes. For the price, the Terate product was hard to beat. 

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