<jats:title>Abstract</jats:title>
          <jats:p>Valorization of waste for chemical processes addresses a challenging task for the society. Soda lignin (<jats:bold>AL</jats:bold>) available in the pulp industry operated in a photocatalytic cycle CuX<jats:sub>2</jats:sub>/<jats:bold>L</jats:bold> (X: Br, Cl; <jats:bold>L</jats:bold>: Me<jats:sub>6</jats:sub>TREN: Tris[2-(dimethylamino)ethyl]amine) and to initiate radical photopolymerization of methyl methacrylate (MMA) with α-bromophenylacetate (EBPA) by exposure at 420 nm. This resulted in poly(methyl methacrylate) (PMMA<jats:bold>)</jats:bold> exhibiting a dispersity &lt;1.3 with CuX<jats:sub>2</jats:sub>/L loading of ≲52 ppm. Deactivator reduction increased dispersity. MMA, styrene, and benzyl methacrylate successfully served as monomers for chain extension and block copolymerization experiments. This worked with CuX<jats:sub>2</jats:sub>/L ≥ 6.5 ppm, although conventional radical polymerization additionally competed. Adding of sodium pyruvate enabled radical photopolymerization under air. Modification of lignin with an aryl sulfonate group resulted in a one-component photoinitiator. It successfully initiated radical photopolymerization of a monomer mixture of (hydroxyethyl)methacrylate (HEMA) and urethane dimethacrylate (UDMA). Scale-up experiments approved practicability of photo-ATRP.</jats:p>