WebMay 1, 2024 · 2. Single chain model. The basic postulates of the original freely jointed chain (FJC) theory are as follows: (i) the macromolecule behaves like a chain of freely jointed segments (i.e., Kuhn segments); (ii) every segment in the polymer chain has the same length; (iii) the segments are rigid. WebApr 1, 2012 · The main pathway of degradation is given for each sample. It results in oxidation, chain scission or cross-linking. Cross-linking levels are dependant on the type of ageing, the chemical structure ...

Chain scission - Wikipedia

http://polymerdatabase.com/polymer%20chemistry/Thermal%20Degradation.html WebAug 14, 1998 · The role of chain scission in the mechanical degradation of polyethylene has been examined using Fourier transform infrared spectroscopy to measure changes … python numpy sort values

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Susceptibility to photo-oxidation varies depending on the chemical structure of the polymer. Some materials have excellent stability, such as fluoropolymers, polyimides, silicones and certain acrylate polymers. However, global polymer production is dominated by a range of commodity plastics which account for the majority of plastic waste. Of these polyethylene terephthalate (PET) has only m… WebThe result of these reaction is enbrittlement and cracking of the polymer. Termination by chain scission, on the other hand, results in the decrease of the molecular weight leading to softening of the polymer and reduction of the mechanical properties. R n · + R m · → R n-2 −CH=CH 2 + R m. 2 RCOO· → RC=O + ROH + O 2 WebDuring thermal degradation, random-chain scission, end-chain scission and side-chain cleavage can occur.[2] Chain scission will reduce the molecular weight and change the molecular weight distribution of the polymer and hence will significantly affect the viscosity and flow properties; and further affecting on the quality of the polymer processes. python numpy tanh