Polyethylene sebacate

Polyethylene adipate Polyethylene suberate Polyethylene azelate Polyethylene sebacate Polyethylene decamethylate Polytetraunethylene succinate Polytetramethylene adipate Polytetramethylene sebacate Polyhexamethylene sebacate Poly-2,2-dimethyItrimethylene succinate... 

Figure 6. Relationship between Tm and the biodegradability of polyesters by R> delemar (a) and R> arrhizus (b) lipases, and PEA-degrading enzyme from Penicillium sp. strain ll+-3 (c). PESu polyethylene suberate PEAz polyethylene azelate PESE polyethylene sebacate PEDe polyethylene decamethylate PBS polytetramethyl-ene succinate PBA polytetramethylene adipate PBSE polytetra-methylene sebacate PHSE polyhexamethylene sebacate PPL poly-propiolactone.

Specific heat of synthetic high polymers. IX. Polyethylene sebacate). J. Polymer Sci. 32, 125-130 (1958). 

Polymers like starch and cellulose derivatives, poly(methyl vinyl ether-co maleic anhydride), hydrophobic dextranes, poly(3-hydroxybutyrate-co-hydroxyvalerate), polyethylene sebacate, polycyanoacrylates, and poly(methyl methacrylates) have been investigated as alternative polymers [19-25]. 

Guhagarkar SA, Malshe VC, Devarajan PV (2009) Nanoparticles of polyethylene sebacate a new biodegradable polymer. Aaps Pharmscitech 10(3) 935-942... 

Mori [75] characterised the end-groups of polyethylene sebacate as a function of molecular size by derivatisation of the hydroxyl and carboxyl groups with 3,5 dinitro... 

Plasticizers and Processing Aids. Petroleum-based oils are commonly used as plasticizers. Compound viscosity is reduced, and mixing, processing, and low temperature properties are improved. Air permeabihty is increased by adding extender oils. Plasticizers are selected for their compatibihty and low temperature properties. Butyl mbber has a solubihty parameter of ca 15.3 (f /cm ) [7.5 (cal/cm ) ], similar to paraffinic and naphthenic oils. Polybutenes, paraffin waxes, and low mol wt polyethylene can also be used as plasticizers (qv). Alkyl adipates and sebacates reduce the glass-transition temperature and improve low temperature properties. Process aids, eg, mineral mbber and Stmktol 40 ms, improve filler dispersion and cured adhesion to high unsaturated mbber substrates. 

In the case of copolymers a calorimetric investigation by Dole and Wunderlich (1959) of the copolyester, polyethylene terephthalate and sebacate) at the 80/20. (80 moles of terephthalate units to 20 of sebacate)... 

The agreement between heats of fusion of the same polymer is excellent in some cases, but very poor in others. Obviously, in the case of polypropylene more work needs to be done before the heat of fusion of this substance will be known with any certainty. Heats of fusion calculated from the copolymer equation, Eq. (6), are uniformly low, except in the case of Rybnikar s data. As pointed out by Dole and Wunderlich (1957) this is probably due to the failure to measure the maximum melting of carefully annealed samples. Thus, Dole and Wunderlich (1959) found that the calorimetrically estimated melting point in the case of the carefully annealed copolyester, the 80/20 polyethylene terephthalate and sebacate, was 240° C, whereas the value calculated from Eq. (6) using the heat of fusion estimated from the calorimetric data of Smith and Dole (1956) was 245° C. The unannealed sample had a melting point of ca. 210°. 

Fig. 11. Specific heat of annealed80/20 copolyester of polyethylene terephthalate-sebacate in the neighborhood of the melting point. Dotted line, calculated values from adaptation of theory of Feory...

For spray coating, polymer solutions and dispersions should be diluted with suitable solvents. Some products need the addition of a plasticizer such as dibutyl sebacate, dibutyl phthalate, glyceryl triacetate, or polyethylene glycol. Different types of plasticizer may be mixed to optimize the polymer properties for special requirements. 

The dimerization of half esters to l,n-diesters is also called Brown-Walker electrolysis. Thereby valuable intermediates for the synthesis of medium-sized rings or l,n-difunctionalized compounds can be prepared (Table 2, entry 4). This reaction is also of industrial interest since in this way sebacic acid can be prepared from adipic acid half ester. This process has been scaled-up in Germany, the USSR and Japan, and yields as high as 93% have been reported. Reaction conditions and yields for the coupling of other half esters have also been studied in detail. 1, -Polyethylene- or polydifluoromethylene-dicar-boxylic acids are reported to be formed by electrolysis of azelaic acid or perfluoroglutaric acid. Ketocarboxylic acids can be coupled to 1,4-, 1,6- or 1,14-diketones (Table 2, entries 9 and 10). Aldehydes must be dimerized in the form of their acetals to obtain good yields, as has been shown for (17) and (18). The arrow on (10)-(18) indicates the location of dimerization, along with the yield and reaction conditions. 

To control use of critical chemicals, various types of regulations were used. The basic one (NPA order M-45) was designed to provide for distribution and use of limited supplies of chemicals so as best to serve the interests of national defense and civilian production. Approximately 10 chemicals were controlled by this order. These included naphthenic acid, polyethylene, resorcinol, sebacic acid, methylene chloride, methyl chloride, Thiokol, Teflon, sulfuric acid, and plastic-type nylon. 

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