Poly(ethylene terephthalate)‐based molecularly imprinted polymers (MIPs) were synthesized, and their recognition capability was evaluated. Adsorption isotherm was described by the Langmuir model and the maximum adsorption capacity of MIPTy reached 172.4 mg g−1 in water at pH 6.2. A recognition coefficient of 1.17 was obtained. A solid‐phase extraction cartridge was manufactured and its behavior was evaluated for tylosin extraction from aqueous and milk samples. An off‐line SPE‐UV method was applied. An acceptable linearity was obtained in the range of 1–20 μg ml−1 and the average recovery at three spike levels in milk samples was higher than 92%. The limit of quantification was 2.6 × 10−2 μg ml−1. The manufactured SPE cartridge has a great potential for clean‐up processes in complex media. The cartridge offers a fast and sensitive option to the existing sorbents for extracting this drug from milk samples.

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.