Preparation and evaluation of rubber seed oil based polymer
processing additives
Okieimen*, F. E. and Sogbaike, C. E.
University of Benin, Industrial Agricultural Products Research
Laboratory,
Benin City, Nigeria.
ABSTRACT
Rubber seed oil
(specific gravity 0.926, acid value 23.0mkKOH/g, iodine value
155.6gI2/100g, free fatty acid 11.26%, oleic acid 20.61%, linoleic
acid 36.62% and linolenic acid 22.5%) was epoxidised and
characterisied by chemical method. Soaps (barium and cadmium) of the
raw and epoxidised oils were prepared by metathesis in alcohol
solution and characterized by thermogravimetry. The effect of the
rubber seed oil derivatives on the thermal degradation of PVC was
examined using rate measurement at 1% conversion of polymer, dilute
solution viscosity measurements on degraded PVC samples and
thermogravimetry. The results of the kinetic studies show that the
rubber seed oil derivatives retard the rate of dehydrochlorination.
Also, changes in the viscosity polymer samples indicate that the
derivatives of rubber seed oil reduce the extent of polymer chain
scission associated with the thermal degradation of PVC.
Thermogravimetric data obtained are consistent with the observed
stabilising effect of the rubber seed oil derivatives in the thermal
degradation of PVC. The order of stabilising effectiveness was found
to be: mixture of epoxidised rubber seed oil and metal soaps of the
oil > metal soaps of epoxidised oil > metal soaps of oil > raw
rubber seed oil. The results of preliminary studies indicate that
the epoxidised rubber seed oil is a good plasticizer form of PVC.
