In recent years, the pursuit of new polymer materials based on renewable raw materials has been intensified with the aim of reusing waste materials in sustainable processes. The synthesis of a lignin, styrene, and butyl acrylate based composite was carried out by a mass polymerization process. A series of four composites were prepared by varying the amount of lignin in 5, 10, 15, and 20 wt.% keeping the content of butyl acrylate constant (14 wt.%). FTIR and SEM revealed that the –OH functional groups of lignin reacted with styrene, which was observed by the incorporation of lignin in the copolymer. Additionally, DSC analysis showed that the increment in lignin loading in the composite had a positive influence on thermal stability. Likewise, Shore D hardness assays exhibited an increase from 25 to 69 when 5 and 20 wt.% lignin was used respectively. In this same sense, the contact angle (water) measurement showed that the LEBA15 and LEBA20 composites presented hydrophobic properties (whit contact angle above 90°) despite having the highest amount of lignin, demonstrating that the interaction of the polymer chains with the –OH groups of lignin was the main mechanism in the composites interaction.

Thermal degradation of Poly(ethylene terephthalate) (PET) bottles waste was carried out by glycolysis using triethyleneglycol (TEG) as nucleophilic agent and N¹,N²-bis(2-aminobenzyl)-1,2-diaminoethane zinc(II) (ABEN), in order to test this compound as catalyst in the degradation of PET until to obtain short chains of polyester (oligomers). The depolymerization processes was tested at 180, 190 and 210 °C, and two molar ratios of PET:TEG (1:1.3 and 1:2.6), the amount of catalyst used was fixed at 1% in relation to PET, the best experiment of PET glycolysis was found at 190 °C during two hours in a mass relation PET:TEG 1:1.3. All products were analyzed by Fourier transform infrared spectroscopy (IR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC), the behavior of the reaction rate was studied for the best experiment by measuring the amount of degraded PET at different glycolysis time. The degradation of PET was favored with the use of ABEN, which accelerates the reaction, obtaining oligomers in the absence of an organic solvent or reaction medium, this is the most efficient catalyst found so far. The oligomers were obtained with molecular weight between 900 and 1500 g mol^-1 depending on the reaction time, 60 min was the less time of the total glycolysis of PET. Also was found that the molecular weight of the oligomers increased along the glycolysis, due to the recombination with TEG and ethylene glycol produced in degradation.