Poly , ester decomposition

The poly(ester-imides) are produced by the thermal decomposition of the soluble polytamic acids) which are obtained by the condensation of ail aromatic diamine and the bis-fester anhydride) of trimeUitic anhydride as shown in the following equation ... 

Monomer production is a general reaction of the methacrylates. Ester decomposition yielding methacrylic acid and the corresponding olefin is possible when the alcohol residue has P hydrogen atoms it becomes the most important mechanism in the case of tertiary esters like poly-t-butylmethacrylate but is competitive with monomer formation in ethyl- and n-butylmethacrylates. 

The copolymer of e-caprolactone and 11-aminoundecanoic acid-based poly(ester amide) exhibits good mechanical properties and thermostability. The melting temperature, heat of fusion and decomposition temperature all increase with an increase in 11-aminoundecanoic acid content in the polymer. ... 

Special types of hydrogen donors include phenols and aromatic amines. Notably, aromatic amines are also known as accelerators in peroxide curing of unsaturated poly(ester)s resins. The mechanism of the decomposition of peroxide radicals by aromatic amines is shown in Figure 19.3. 

Scheme 6 Ester decomposition in poly(sec-butyl methacrylate)...

The formation of alkene and CO2 from PEA, poly(propyl acrylate) (PPA), poly(butyl acrylate) (PBA) and poly(2-ethylhexyl acrylate) (P2EHA) can be explained by a side group ester decomposition of radical (C) as in Scheme 10. This mechanism also leads to unsaturation and provides further possibility for crosslinking. 

In order to study the molecular dynamics of the outer segments of a dendrimer, one pyrene moiety was selectively and covalently attached to one dendron of poly(aryl ester) dendrimers by Adams (in total three pyrene molecules per dendrimer) [24]. The fluorescence decay of pyrene in the THF solution of the labeled dendrimers provided details of the pyrene excimer formation, such as the excimer formation rate, the excimer decomposition rate constant and the equilibrium constant of the excimer formation. These parameters were utilized to evaluate the diffusional mobility of the dendrimer branches. 

Most crystalline polymers do not exhibit a crystalline melting point but a decomposition point where depolymerization starts (ca. 340 °C for poly-DSP and ca. 420 °C for poly-PDA phenyl ester by DSC). The decomposition point, however, is not strictly definable, because it is greatly affected by the morphology and the molecular weight of the polymer (see Sect. VI. a.). 

The thermal decomposition of 1,1,1,-trifluoroacetone has been studied by Fekete - , and that of fluoroacetone hemiacetal esters by Newallis et Lewis and Newman have reported on the rearrangements of fluoroesters in the gas phase. Thermal reactions of nitrogen-containing fluoro-compounds have included trifluoromethyl cyanide , hexafluoroazomethane , tetrafluorohydra-zine , fluorodiazirines , perfluoropyridazines , fluorochlorodinitrometh-ane and poly(difluoroamino)fluoromethanes - . ... 

The most common polymer of a vinyl ester is poly(vinyl acetate), CAS 9003-20-7, with the formula [-CH2CH(OC(0)CH3)-]n. Other vinyl esters also are known, such as poly(vinyl butyrate), poly(vinyl benzoate) CAS 24991-32-0, and poly(vinyltrifluoroacetate), CAS 25748-85-0. Poly(vinyl acetate) is typically obtained from the monomer with radical initiators, either by emulsion or suspension polymerization. The polymer Is used in water-based emulsion paints, adhesives [22], gum base for chewing gum, etc. Also, poly(vinyl acetate) is used as a precursor for the preparation of other polymers such as poly(vinyl alcohol) or poly(vinyl acetals). Thermal decomposition of poly(vinyl acetate) starts at a relatively low temperature, around 200° C, some of the reports regarding its thermal decomposition being given in Table 6.5.8 [13]. The same table includes references for poly(vinyl butyrate) and poly(vinyl cinnamate), CAS 9050-06-0. 

Table 6.5.8. Summary regarding literature information on thermal decomposition of several poly(vinyl esters).

The glass transition point of these materials decreases as the number of carbons in the alcohol increases. Thermal stability and pyrolysis products of polyacrylates have been thoroughly studied [23-29]. Some literature results regarding thermal decomposition of poly(acrylic acid esters) are summarized in Table 6.7.4 [6]. 

In ASA terpolymer acrylic acid brings more flexibility and the material has very good mechanical properties and weather resistance. For these reasons ASA is extensively used in automotive industry and in the fabrication of various appliances. Even more frequently than acrylic acid itself, various acrylates are used in copolymers. Among these can be mentioned the copolymers of acrylic acid esters with methacrylic acid esters such as poly(methyl methacrylate-co-methyl acrylate), poly(methyl methacrylate-co-ethyl acrylate), poly(methyl methacrylate-co-butyl acrylate), poly(ethyl methacrylate-co-ethyl acrylate), poly(acrylonitrile-co-methyl acrylate), poly(alkyl acrylate-co-methyl methacrylates), and poly(alkyl acrylate-co-hydroxyethyl methacrylates) where alkyl can be methyl, ethyl, butyl, etc. Some literature information regarding thermal decomposition of copolymers including acrylic acid and acrylic acid esters is given in Table 6.7.8 [6],... 

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