POLYMER INSTITUTE BRNO (PIB), formerly known as the Research Institute of Macromolecular Chemistry (RIMC), has long been the research base of the applied research in the field of polymers. The shape of the Institute is a result of its more than 60 years´ evolution. Being for many years a state-sponsored organisation, the interests of RIMC were very broad - although always directed at areas more industrial than academic. However, the Institute has long cooperated closely with a number of universities and academic institutions at home and abroad.

Having a long tradition in Ziegler-Natta catalyst research and polymer stabilisation, the position of the Institute became quite clear-cut, particularly after the building of polyolefin production plants in Chemopetrol Litvínov in early seventies. Since then activities have been focused mainly on polyolefin catalyst research, new resin grades development, post-reactor modification of polymers (reactive compounding, reactive extrusion, polymer alloys, fillers), new formulations of additives (stabilisers, colour concentrates, antistatics, etc.) and trouble-shooting.

In 1994, in the course of the second privatisation wave, the Institute became a limited liability company with the status of an independent contract research organisation in which a German firm Consil VBmbH and a Czech petrochemical company Chemopetrol, a.s. had their capital share. In 2004, Chemopetrol, a.s. bought out the whole share from both owners and the Institute thus became a daughter company of the biggest petrochemical complex in the country. After the privatization of Unipetrol an ownership interconnection was created with Unipetrol Orlen Group. And now, after the merger (December 31, 2015), PIB is a part of Unipetrol RPA as „UNIPETROL RPA, s.r.o. - POLYMER INSTITUTE BRNO, odštěpný závod“. ​

The company name was changed in early 2021 to „ORLEN Unipetrol RPA s.r.o. - POLYMER INSTITUTE BRNO, odštěpný závod“. ​​