The recommended dosage is 0.3-1.5% of the total amount depending on the application.
Direct addition, high speed dispersion in systems with similar viscosity or dilution with solvent.
RAFT reagent is a reversible addition-fragmentation chain transfer agent. It has chemical bonds that are prone to addition reaction and cleavage reaction in its molecular structure, which initiates the reversible addition-fragmentation chain transfer (RAFT) living radical polymerization of monomers. fischer tropsch wax msds . The basic structure of RAFT is shown in the formula.
Z is an activating group, which can activate C-S; R is a leaving group, which is broken to form a free radical R· which can initiate polymerization again. The chain transfer constant of RAFT reagent depends on the properties of the groups X, Z and R. When X is sulfur, that is, when the chain transfer agent is a dithioester compound, the chain transfer constant of the RAFT reagent is larger. Commonly used RAFT reagents include dithioesters
trithiocarbonates, dithiocarbamates, sulfonates (dithiocarbonates), and phosphoryl/thiophosphoryl dithioformates.
Dithioester RAFT reagents contain characteristic dithioester groups (SCC) and substituents R and Z. These groups can affect the chain transfer constants of RAFT reagents, thereby affecting the stereoregularity of the final polymer molecule. Therefore, determining the type and amount of RAFT reagent is the key to RAFT living polymerization. Commonly used ethyl groups include Ph, SCH z Ph, CHA, pyrrole, OC oF s, lactam, OPh and N(C2Hs) z, and commonly used R groups include C(CH): CN, C(CH&) z Ph , C(CHa) zC Hz C(CHy) a, CH(CHs) Ph, C(CH) ): and CH: Ph. The order of activity change of the Z group: aryl>alkyl>-OPh and -NH 2 The leaving ability of the R group is greatly affected by the steric effect and polarity of the substituent. Generally, as the steric hindrance and polarity increase, the leaving ability of the R group is significantly enhanced.
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