Use of Hydroxypropylmethylcellulose as Thermo-Responsive Flocculant in Skim Natural Rubber Latex
To recover residual rubber from skim natural rubber (SNR) latex, the effective and environmentally friendly methodology developed based on using hydroxypropylmethylcellulose (HPMC) as a thermo-responsive flocculant. The SNR particles could be completely separated to form high concentrated latex as cream phase within only 5 hours. Almost 100% of SNR was recovered when using HPMC 0.7%w/w. Quality of SNR obtained from this technique was higher and color of it was lighter than SNR obtained from the conventional method. HPMC could be easily precipitated from the serum phase by heating the serum phase at about 70 °C. The cloud point and the precipitation point of HPMC were affected by the additions of α-D-glucose, sn-phosphatidyl chloride and inorganic salts. It was found that reduction of the cloud point and the precipitation point of HPMC also depended on both concentration and type of cations and anions of inorganic salts.
N. Moonprasith et al., "Use of Hydroxypropylmethylcellulose as Thermo-Responsive Flocculant in Skim Natural Rubber Latex", Advanced Materials Research, Vols. 55-57, pp. 913-916, 2008