The trend in recent years has been to promote a circular economy and save non-renewable resources. Polymers most commonly are used in composites, where they can be combined with other polymers or fillers to produce a composite with desired properties. For example, natural fiber composites are an excellent way to obtain high-strength materials. However, to achieve this, the best possible compatibility between polymer matrix and natural fibers must be ensured. According to literature natural fibers need to be pretreated to obtain better interfacial interactions. Besides, it is necessary to use compatibilizers in creation of composites in order to improve the compatibility between polymer matrix and natural fiber, obtaining materials with higher mechanical properties. Maleic anhydride (MAH) grafted polymer is a compatibilizer, which is very effective and commonly used for natural fiber and polymer matrix at the interfacial agent. MAH is produced from non-renewable resources, so the aim of the work was to develop biobased compatibilizers and assess their effectiveness. Tannic acid (TA), catechin hydrate (CA) and stearic acid chloride (SC) were used for the synthesis of the biobased compatibilizers (SCTA and SCCH). The synthesis process was carried out according to modified procedure of M.M.S.Abdullah . The compatibilizer effect was evaluated for recycled polypropylene/polyethylene compositions with 10 % and 40 % rapeseed straw fibers. The results of mechanical properties (tensile, flexural, impact strength) showed that the developed compatibilizers have the potential to replace MAH. Moreover, the addition of SCTA and SCCA to the composite showed excellent thermo-oxidative properties, providing very high stabilization in oxygen environment at 190 °C. Composites formed with SCTA and SCCA showed high surface wetting properties than with MAH; the wetting angle reached up to 90°, granting a more hydrophobic surface.