Synthesis of MgO-Lignin Hybrids

MgO-lignin hybrids were obtained using magnesium oxide and kraft lignin. The final products in the form of MgO-lignin systems were prepared at three different ratos: (i) one part by weight of MgO for 5 parts by weight of lignin (1:5); (ii) one part by weight of MgO per one part by weight of lignin (1:1); (iii) five parts by weight MgO for one part by weight of lignin (5:1). Both components were mechanically connected by grinding and homogenizing the system in a planetary ball mill (Fritsch GmbH, Idar-Oberstein, Germany) for 2 h. A detailed description of the production methodology can be found in our previous publications [9 (link),16 (link),27 (link),28 (link)]. Additionally, fillers in the form of pure magnesium oxide and pure lignin were prepared. After milling, the powders were sieved through a sieve with a diameter of 80 mm. Then, the samples were subjected to further tests. The received materials are presented on a digital photo (see Figure 1).