Emulsion graft polymerization of 4-chloromethylstyrene on kenaf fiber by pre-irradiation method

The stability of micelle size in 3% 4-chloromethylstyrene (CMS), 0.3% Tween 20 in water emulsion over time was studied using a static light scattering. It was found that the micelle diameter decreased with storage time and temperature. The influence of micelle size over time was then explored by adjusting the ratio of CMS to Tween 20 (10:1, 10:2, 10:4) at CMS concentration of 0.2–5.0%. It was found that the increase in average micelle diameter resulted in a decreased in the stability of CMS emulsion. Graft polymerization of CMS on kenaf fiber was carried out in emulsion with 350 nm micelle at various CMS concentrations at a dose of 150 kGy. It was found that the degree of grafting (Dg) was strongly dependent on the monomer concentration and time. However, the increase in micelles diameter from 250 nm to 500 nm resulted in the increased in Dg from 3% to 153%. This extraordinary result led us to investigate the micelle size distributions of CMS emulsion during graft polymerization. It was found that the diameter of micelle decreased rapidly to 100 nm within 2 h. It was discovered from digital photomicrography the existence of multiple emulsions in the CMS emulsion. It was proposed that the enhancement of grafting yield is governed by emulsion breakdown mechanisms through radical effect during radiation induced graft polymerization.

► The stability of 4-chlorometylsyrene (CMS) emulsion was studied by static light scattering and optical microscope.
► Different micelle size was obtained by adjusting the ratio between CMS and Tween 20.
► Effect of micelle size on radiation induced graft polymerization onto kenaf fiber was evaluated.
► Microscope observations of the CMS emulsion revealed that some of the micelles were of a multiple type.
► Mechanism during radiation induced graft polymerization was predicted.