Pyrolysis of random and block copolymers of ethyl acrylate and methyl methacrylate

Abstract

SynopsisPyrolysis gas chromatography can distinguish random from block copolymers of ethyl acrylate and methyl methacrylate. The pyrograms depend on the pyrolytic temperature, the ratio of copolymerized monomers, the degree of conversion, and the method of polymerization. Larger amounts of ethyl methacrylate and methyl acrylate are formed on pyrolysis of random copolymers than of block copolymers. The presence of mixed dimers indicates random copolymerization. The sum of the percent recovery of ethyl alcohol and ethyl acrylate is fairly constant over a range of compositions and monomer sequence. Random copolymers produce less ethyl alcohol than ethyl acrylate on pyrolysis, while homopolymers and block copolymers produce more ethyl alcohol and less ethyl acrylate. In a set of random copolymers with different EA/MMA ratios, there is an increasing per cent recovery of EA monomer with decreasing EA in the COpolymer, while ethyl alcohol shows the opposite behavior. The characteristic degradation patterns are thought to be governed by the availability of the tertiary hydrogen for abstraction by the alkoxy oxygen of a neighboring acrylate unit, the availability depending on the sequence distribution of acrylate/methacrylate molecules.

Degradation of Poly(butyl acrylate) and Poly(2‐hydroxyethyl methacrylate) Model Compounds Under Extreme Environmental Conditions

“…However, the peak at m/z ¼ 20 ]Na þ , which has an error of 0.016 Da. We cannot explain the occurrence of this peak, other than to speculate that it is likely to contain atoms other than C, H and O, and the inclusion of other species is a matter of speculation.…”

“…[16][17][18][19][20][21][22][23][24][25][26]36,40,[42][43][44][45] However, as with pMMA, much of this work involves degradative conditions that are not overly relevant to a surface coating exposed to the harsh Australian climate over long periods of time. Thermal degradation studies on pBA indicate that it undergoes a number of different reactions, forming volatile products such as CO 2 , 1-butene and 1-butanol, [16] as well as the 'unbuttoning' reaction which yields fragments of the monomer molecules [17] (rather than the 'unzipping' reaction seen in pMMA, which results in intact monomer molecules [46][47][48][49] ).…”

“…[19] No monomer was evolved at these temperatures, however butyl acrylate may evolve at higher temperatures. [20,21] Haken and Tan [22,23] pyrolysed a series of poly(alkyl acrylate)s, including pBA, and again found butyl formate, butyl acetate, and saturated and unsaturated dimers. They propose the butyl acetate formation is occurring via scission at the chain end and addition of hydrogen.…”

Evidence of waste electrical and electronic equipment (WEEE) relevant substances in polymeric food-contact articles sold on the European market

“…By a similar mechanism, PS blends and co-polymers like styrene–acrylonitrile co-polymer (SAN) and ABS fragment by a similar mechanism, however, the styrenic part favours mainly a β-scission reaction resulting in a high quantity of unzipped styrene, α-methylstyrene, styrene dimers and trimers (Rutkowski & Levin 1986 ; Westerhout et al 1997 ; Achilias et al 2007 ). Acrylic polymers have similar fragmentation patterns as the acrylate esters appearing in the pyrograms are the most abundant (Straus & Madorsky 1953 ; Wallisch 1974 ). Condensed polymers like PA, PET, polybutylene terephthalate (PBT) and PC can also be evaluated by pyrolysis GC-MS.…”

Photocatalytic degradation of methyl methacrylate copolymers

“…In this process, the structure of the comonomer plays a crucial role in determining the properties, especially, T g and thermal decomposition temperature. Several studies have thoroughly evaluated the mechanism and products of thermal degradation of the copolymers of methyl methacrylate with styrene [1], acrylonitrile [2], alkyl(acrylates) [3][4][5] and methacrylic acid [6]. Though the assessment of the thermal stability is an important aspect, it is relatively less significant when considering polymer surfaces that are exposed to sunlight and other artificial weathering conditions, which undergo continuous and/or cyclic stresses resulting in the deterioration of surface, mechanical and chemical properties such as colour, surface texture, tensile strength, impact resistance, resistance to chemicals, etc., even at moderate temperatures [7].…”