Title of article :
Effect of an added base on (4-cyanopentanoic acid)-4-dithiobenzoate mediated RAFT polymerization in water
Author/Authors :
Albertin، نويسنده , , Luca and Stenzel، نويسنده , , Martina H. and Barner-Kowollik، نويسنده , , Christopher and Davis، نويسنده , , Thomas P.، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2006
Pages :
9
From page :
1011
To page :
1019
Abstract :
The effect of an added base on the aqueous reversible addition–fragmentation chain transfer polymerization of a methacrylic glycomonomer with (4-cyanopentanoic acid)-4-dithiobenzoate was investigated. When sodium carbonate or sodium bicarbonate were used to dissolve the RAFT agent in aqueous solution at room temperature, an inhibition period of 60–90 min was observed at the beginning of the polymerization together with a marked decrease in the overall polymerization rate. Also, experimental Mn values were much higher than the calculated ones in both cases. When sodium carbonate was used, control over the polymerization process was lost within 43% conversion. Better results were obtained with sodium bicarbonate, in which case the molecular weight distribution remained narrow and unimodal up to 81% conversion. At that point, a higher molecular weight shoulder developed that kept growing in intensity at the proceeding of the reaction. Dramatically improved results were obtained by adding circa 10% ethanol to the polymerization mixture to facilitate the dissolution of (4-cyanopentanoic acid)-4-dithiobenzoate. Following this protocol, narrow polydispersity poly(methyl 6-O-methacryloyl-α-d-glucoside) was obtained possessing a molecular weight close to the predicted value.
Keywords :
Aqueous RAFT polymerization , Living radical polymerization , RAFT agent
Journal title :
Polymer
Serial Year :
2006
Journal title :
Polymer
Record number :
1725630
Link To Document :
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