Polymer degradation processes

GRASSIE, n., Chemistry of High Polymer Degradation Processes, Butterworths, London (1956)... 

This indicated that the polymer degradation process was likely sensitized by monomeric rather than polymeric rose bengal. 

Alternative Polymer Degradation Processes, (e.g., Photochemical, Plasma,... 

Grassie N, "Chemistry of High Polymer Degradation Processes", Interscience, New York, 1956. 

Two steps occur in the microbial polymer degradation process, first, a depolymerisation or chain cleavage step, and second, mineralisation. The first step normally occurs outside the organism due to the size of the polymer chain and the insoluble nature of many of the polymers. Extracellular enzymes are responsible for this step, acting either endo (random cleavage of the internal linkages of the polymer chains) or exo (sequential cleavage of the terminal monomer units in the main chain). 

Grassie, N., Chemistiy of Vinyl Polymer Degradation Processes, Butterworth, London, 1956. 

Grassie,N. Chemistry of high polymer degradation process. London Butterworths Sci. 1959. 

The first step of the hydrocarbon polymer degradation processes is the formation of polymeric alkyl radicals (P") and its reaction with oxygen to give peroxy radicals... 

The need for a quantitative working TGA - coupled - FTIR/MS system was clearly felt in our laboratory mainly to study the first stage(s) of polymer degradation processes but also to determine small amounts of residual solvent and/or residual monomer(s) in polymeric systems. First, a Perkin Elmer TGA -coupled - FTIR system was purchased and adapted to allow quantitative determinations. A Balzers MS was subsequently purchased and coupled, using the method described by Dufour and Raemaekers [4], in parallel with the FTIR resulting in a TGA - coupled - FTIR/MS system [11]. The TGA/FTIR and the TGA/MS coupling, the systems modifications and calibrations and some typical results are described in this chapter. 

IR spectroscopy is a popnilar method for characterizing polymers. This spectroscopy may used to identify the composition of polymers, to monitor polymerization processes, to characterize polymer structure, to examine polymer surface, and to investigate polymer degradation processes. There are several reports of use of IR spectroscopy to evaluate grafting of acrylic monomers onto natural materials as carboxymethyl cellulose (CMC) and chicken feathers (CF) (Martinez et al, 2003, 2005, Vasile et al, 2004, Zohuriann-Mehr et al, 2005, Joshi and Sinha, 2006). 

A schematic illustration is shown in Fig. 15.5 to describe the main mechanism in polymer degradation process. 

Factors governing polymer degradation Processing Service lifetime ... 

Pieichowski, J., Pielichowski, K. (1995). Application of thermal analysis for the investigation of polymer degradation processes, J. Therm. Anal, 43, 505-508. 

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