Webhydride SiH, vinyl (in the polymer chain or at the end of the chain), dimethylene -CH. 2-CH. 2-, methine -CHCH. 3-, MePh and Ph. 2. groups have been studied. In the case of SiH-silicone, … WebChain scission has been discussed as a process involving medium cages and diffusion of polymer fragments out of such cages. Two types of processes can be distinguished: completion of potential ...
Chain scissions in a polymer network - Horikx - 1956 - Journal of ...
WebMar 9, 2024 · 2.- CHEMICALS: chain breakage (scission), changes in lateral substituents, crosslinking reactions, other chemical reactions etc. Each external agent that leads to polymer degradation results in a different degradation mechanism (and modifies the polymer structure).. Types of polymer degradation WebThese polyesters contain either alkoxyphenacyl or coumarin chromophores embedded along the polymer chain. The alkoxyphenacyl polyesters … dallas registering vehicle
Photoresponsive Coumarin Polyesters That Exhibit Cross-Linking …
WebNov 17, 2024 · With data on both mechanophore activation and backbone scission, the mechanophore activation selectivity can be studied using the extent of ring-opening extrapolated to one scission cycle (ϕ), as defined by Craig, 8b which can be obtained from plots of gDCC ring-opening versus chain scission cycle, where ϕ is the slope of the … WebPolymer oxidation has caused accidents involving medical devices. One of the oldest known failure modes is ozone cracking caused by chain scission when ozone gas attacks susceptible elastomers, such as natural rubber and nitrile rubber. They possess double bonds in their repeat units which are cleaved during ozonolysis. WebMar 1, 2010 · In general high energy radiation like gamma-rays can lead to polymer chain scission and, depending on the polymer, result in lower molecular weight or crosslinking [22, 23]. dallas registry of actions