A polymer matrix composed of Gg-cl-poly(MAA) was prepared by using N,N´-methylene-bis-acrylamide (MBA) as crosslinker and Ammonium persulfate (APS) as initiator under vacuum oven.
Ammonium persulfate (APS) is a thermal initiator that decomposed under heat and lead to the formation of sulphate ion radicals, which, on further reaction with water molecules, gave hydroxyl (OH*) radicals. OH* and sulphate (SO4-*) radicals reacted with the monomer and backbone molecules to produce free-radical sites. Someone told me that the probability of hydrogen atom abstraction by sulfate radical ion or OH radical from an -OH functional group of the polysaccharide is so low that such reactions can be neglected and suggested that the main reaction is hydrogen atom abstraction from carbon atoms in the sugar, and not from -OH groups. Therefore the linkage to methacrylate does not occur via an oxygen atom, but by direct addition of a carbon-centered sugar radical to the double bond of the monomer.
The reaction scheme for the sulfate radical ion (and/or OH radical) attacks on the polysaccharide structure is attached below. Is the scheme is correct, or do I need to modify something?
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Polymers