a method of producing a composition which is composed of from 5 to 50 wt . % of caoutchouc , preferably natural caoutchouc ; from 4 to 25 wt . % of starch powder ; from 10 to 50 wt . % of one of polybetahydroxybutyrate or cellulose ; and from 0 to 15 wt . % of auxiliary agent , and which is biodegradable includes providing caoutchouc in one of flaked or granular form ; providing initial materials selected from the group consisting of starch , polybetahydroxybutyrate , cellulose , and auxiliary agent , in ground form as one of a powder or granulated ; homogeneously mixing the initial materials into the caoutchouc to provide a homogeneous mixture : plasticizing the homogeneous mixture by heating in one of a screw - type extruder or injection molding machine to provide a plasticized mass ; and ejecting the plasticized mass from the extruder or injection - molding machine and allowing the mass to cool . preferably , plasticizing is carried out of a temperature ranging from 170 ° c . to 180 ° c .