Thermal degradation of poly

Wakeman, LB. and Johnson, H.R., Vinyl Chloride Eormation from the Thermal Degradation of Poly(Vinyl Chloride), Polym. Eng. Set, 18, 404 (1978)... 

Han S, Kim C, Kwon D (1995) Thermal degradation of poly(ethyleneglycol). Polym Degrad Stabil 47(2) 203-208... 

B. Rimez, H. Rahier, G. Van Assche, T. Arttoos, M. Biesemans, and B. Van Mele, The thermal degradation of poly(vinyl acetate) and poly(ethylene-co-vinyl acetate), Part I Experimental study of the degradation mechanism, Polym. Degrad. Stab., 93, 800-810 (2008). 

Holland, B. J. and Hay, J. N. The kinetics and mechanisms of the thermal degradation of poly(methyl methacrylate) studied by thermal analysis-Fourier transform infrared spectroscopy. Polymer 2001 42 4825. 

T he thermal degradation of poly (vinyl chloride) is now well under- stood to be caused by the ordered loss of hydrogen chloride, initiated at an unstable site, which results in the formation of long, colored polyene chains ... 

THERMAL DEGRADATION OF POLY(VINYL CHLORIDE) PLASTISOLS BASED ON LOW-MIGRATION POLYMERIC PLASTICIZERS... 

W. H. Starnes Jr., Structural and mechanistic aspects of the thermal degradation of poly(vinyl chloride). Prog. Polym. ScL, 27, 2133-2170 (2002). 

The same authors have also studied the effects of particle size on the rate of production of monomer during thermal degradation of poly(methyl methacrylate) and observed that the rate increases with particle size for particles smaller than about 50 mesh but it does fall away for larger particles. The study of the effect of layer thickness on the rate of mononrer production has also revealed the similar pattern of behavior of the polymer towards (tegradation. Several reasons for this behavior of the (tegradation are mentioned. "ITiese are ... 

All of tl products l,3 triphenylbenzene, 1,3-diphenylpropane, 1,3,5-triphenylpen-tane, ethylbenzMie, methylben2 ne, and styrene are volatile products of thermal degradation of polystyrene This kind of intramolecular cyclization is not likely to be important in thermal degradation of poly(methyl methacrylate) and poly(a-methylstyrene), because the reactive site is linked to two bulky substituents which restrict the rotation of the terminal carbon atom containing the unpaired electron and thus prevent it from coming into proper orientation to attack the other carbon atoms in the chain. 

Several studies on thermal degradation of poly acry ic acid) and of its salts are reported in literature [1-5]. Some results from these studies are summarized in Table 6.7.1 [6]. 

Thermal degradation of poly(ethylene-co-carbon monoxide) takes place by chain scission, yielding alkenes and ketone fragments. Around 500° C the decomposition products consist of CO, H2O, ethene, and series of ketones with the general structure R-[-CO-CH2-CH2-]n-CO-R where R, R = -CH3, -CH2-CH3 or -CH=CH2 [2, 3]. 

A number of studies were dedicated to the understanding of the good heat resistance of the polymers from this class [13-15]. One of these studies was done to evaluate the effect of para substitution on the thermal degradation of poly N-arylmaleimides [16]. 

Several studies regarding pyrolysis and thermal degradation of poly(siloxanes) are reported in literature [2-6], some of these being summarized in Table 16.1.1. 

Figure 1.40. Chain scission (given as number of scissions, S, per number-average molecule) during thermal degradation of poly(styrene) polymerized anionically (a), M = 2.3x10, or by free-radical initiation (b), M — 1.5x 10. Adapted from McNeill (1989).

Braun, D. (1981) Thermal degradation of poly(vinyl chloride), in Grassie, N. (Ed.) Developments in Polymer Degradation - 3, London Elsevier Apphed Science. 

PRODUCT YIELDS ASSOCIATED WITH MAXIMA C, D AND E (FIG. 32) IN THE THERMAL DEGRADATION OF POLY-f-BUTYLMETHACRYLATE... 

The first involves elimination of propene and formation of an acid residue on the chain this will catalyse further decomposition of the ester group. Such a mechanism has also been proposed to account for the thermal degradation of poly-t-butylacrylate (see later). It may occur either by a molecular or by a radical process. The molecular reaction may be written as... 

A review and some new results on the thermal degradation of poly-p-xylylene have been presented by Jellinek and Lipovac [303]. Little volatile material is formed but appreciable amounts of dimer, trimer, tetramer and pentamer were isolated. Typical vacuum volatilization curves are given in Fig. 73. It has been proposed that the mechanism consists of random chain scission at abnormal structures in the chain, followed by a depropagation reaction resulting in low molecular weight polymer but very little monomer. 

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