Sustainable development requires taking care of and reusing the waste produced. Here, some strategies for valorization of model biopolymer and biopolymer waste to functional chemicals and carbon products [1-3] and further utilization of the derived products as property enhancers in polylactide (PLA) materials are presented. As an example a two-step industrially viable process for production of flexible fully biobased PLA was demonstrated [2]. First polyhydroxybutyrate (PHB) was recycled to functional oligomers with crotonate end-groups (dPHB) by thermal degradation in an extruder. Second the oligomeric plasticizer candidates were covalently anchored to PLA chain by reactive extrusion. 20 wt% grafted dPHB increased PLA’s elongation at break from 8% to 538 %. In another approach microwave assisted hydrothermal oxidation was utilized to selectively degrade low and high density polyethylene into few well-defined dicarboxylic acids [3,4]. This product mixture was then directly utilized for production of oligoesters, which were covalently coupled to PLA chain through reactive extrusion leading to effectively plasticized PLA [4]. In other studies we hydrothermally carbonized biopolymers and waste products to 3D carbon spheres from which functional 0D carbon dots were produced by oxidation [1]. These dots were shown to be effective nanoenhancers controlling crystallinity, mechanical and barrier properties of PLA materials [5,6]. References [1] N.B. Erdal, K.H. Adolfsson, T. Pettersson, M. Hakkarainen, ACS Sustainable Chem. Eng. 2018, 6, 1246. [2] X. Yang, J. Clenét, H. Xu, K. Odelius, M. Hakkarainen, Macromolecules, 2015, 48, 2509. [3] E. Bäckström, K. Odelius, M. Hakkarainen, I & EC Research 2017, 56, 14814. [4] E. Bäckström, K. Odelius, ACS Sustainable Chem. Eng. 2019, 7, 11004. [5] H. Xu, K.H. Adolfsson, L. Xie, S. Hassanzadeh, T. Pettersson, M. Hakkarainen, ACS Sustainable Chem. Eng. 2016, 4, 5618. [6] H. Xu, L. Xie, J. Li, M. Hakkarainen, ACS Appl. Mater. Interfaces, 2017, 9, 27972