Polyacrylate degradation products

A product is only considered to be totally biodegradable if all its single components can be degraded naturally. Currently, pressure sensitive adhesives (PSA) are mostly based on non-biodegradable synthetic polymers such as polyacrylates, ethylene-vinyl acetate copolymers and styrene block copolymers [124]. Therefore there is a growing demand for the application of biodegradable PSAs on naturally degradable products like paper and cardboard. 

Bisphenol A is used as a raw material to make polycarbonate and epoxy adhesives and can coatings. It is also used in flame-retardants, in unsaturated polyesters and in polyacrylate resins. Many foodstuff containers are made of these resins, including containers for oven and microwave cooking. Recent studies have shown that bisphenol type compounds have both mutagenic and cytotoxic properties [84]. Nerin et al. developed a fast screening method based on SPME and HPLC with fluorescence detection suitable for the analysis of several bisphenol derivatives and their degradation products in aqueous canned foods such as tuna, olives and corn [85]. The best results were obtained with carbowax and PDMS/DVB fibers. The detection limits were between 0.7 and 2.4ngmL while RSDs were between 14 and 32%. After the extraction parameters were optimized, the method was applied to... 

Sulfosuccinic and sulfopropionic acids are economically attractive when synthesized in situ or offsite from maleic anhydride or acrylic acid. Both are subject to oxidation, but should give nonvolatile degradation products. Synthesis of sulfopropionic acid can give undesirable polyacrylic acid impurities. 

Fourier transform infrared (FT-IR) spectroscopy can be used to characterize drug substances, polymer blends, polymer complexes, dynamics, surfaces, and interfaces, as well as chromatographic effluents and degradation products. It provides information about the complexation and interactions between the various constituents in the PECs. It is capable of qualitative identification of the structure of unknown materials as well as the quantitative measurement of the components in a complex mixture. FT-IR spectra of physical mixture and PEC can be determined by FT-IR spectrophotometer using KBr disc method in the range of 4000 to 250 cm h Since the stability and drug substance is very important in several applications, determination of their physicochemical stability is crucial. The FTIR spectra of polyacrylic acid, PVP, metformin hydrochloride, and PEC microparticles of metformin were shown in Figure 56.8. The FTIR spectra of polyacrylic acid and PVP have shown... 

Monomers, dimers and higher-molecular-weight oligomers are the predominant decomposition products of the lower alkyl polymers. The major degradation products of higher alkyl polyacrylates are olefins, alcohols and acrylate monomers (see Table 5), which are different from those of the lower alkyl polyacrylates. 

Table 5. Degradation products and yield of higher and lower polyacrylates Reprinted from [a. 158] with permission from Elsevier ...

Product D adation products of higher alkyl polyacrylate Relative abundance of polyacrylate (%) at 550 °C Degradation products of lower alkyl polyacrylate Relative abundance of polyacrylate (%)... 

The photo-cross-linkability of a polymer depends not only on its chemical structure, but also on its molecular weight and the ordering of the polymer segments. Vinyl polymers, such as PE, PP, polystyrene, polyacrylates, and PVC, predominantly cross-link, whereas vinylidene polymers (polyisobutylene, poly-2-methylstyrene, polymethacrylates, and poly vinylidene chloride) tend to degrade. Likewise, polymers formed from diene monomers and linear condensation products, such as polyesters and polyamides, cross-link easily, whereas cellulose and cellulose derivatives degrade easily. ... 

The branched chain poly tertiary-butyl acrylate has been considered by several workers [36] at low temperatures. Schaefgen and Sarasohn [37] have studied this degradation at several low temperatures. At 160 °C isobutylene was lost quantitatively while above 180 °C approximately half of the weight of the polymer was lost after 12 hours of heating with the gaseous products being 36% isobutylene, 11% water, and 3% carbon dioxide. Elemental analysis of the pyrolysis residue corresponded approximately to polyacrylic anhydride (C H Oj). 

It may be noted here that the thermal degradation of polyacrylates does not follow the same pattern as that of the polymethacrylates. None of the polyacrylates gives appreciable yields of monomer or olefin the principal products are polymeric fragments which arise by chain scission accompanied by transfer of tertiary hydrogen atoms. 

MS has been widely used to identify the products and their formation kinetics in the degradation of filled reaction layers, e.g., phenol-formaldehyde resins [53, 54], epoxide resins, polyesters and polyacrylates [55]. 

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