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.

The rainwater chemistry within the Metropolitan Area of Monterrey (MAM) was studied during a one-year period (January 2019–January 2020) in seven sampling sites. The metal concentration of Zn, Fe, Cd, Cu, Ni, and Mn was analyzed in bulk samples and the toxicity potential (TP) was calculated for each metal. A canonical correspondence analysis (CCA) was applied to identify the relationship between environmental variables and metals concentrations. An average of 26.6 ± 10 mm of rainfall was obtained. A mean pH of 7.2 ± 0.3 and a mean electrical conductivity of 177.8 ± 8.7 µS cm⁻¹ were observed. The average concentration of metals in all sites follows a descending order of Fe> Zn > Mn > Cu > Ni > Cd. The university site shows the highest averages of Fe, Zn, Cu, and Mn, which is attributed to its proximity to the metallurgical industry. The TP value of Cd reflects a risk in all sites and Fe only for the Universidad, Obispado, Pastora, and Santa Catarina sites, using as a reference value the Environmental Protection Agency (EPA) Drinking Water Regulations and Mexican norm NOM-127-SSA1-1994. The CCA analysis showed that only Ni and Cd had a strong correlation with the environmental variable of relative humidity of air.

The current research focused on improving two concrete mixes that contain a Portland cement and fly ash base, along with plant aggregates made from peanut shells (Arachis hypogaea) and sargassum (Sargassum fluitans) to obtain the configuration that would provide the best possible compressive strength (of at least 2 MPa to making them feasible for use in construction), but with the best thermal conductivity properties (lowest value) to improve the insulating capacity of the material. A full orthogonal array (Taguchi, P = 3 and L = 3) with three parameters (water/binder ratio, aggregate/binder ratio, and fly ash use) at three levels was employed to identify the optimized configuration. Additionally, the samples underwent morphological analysis to assess the treatments' efficacy and the compatibility of the raw materials. The statistical analysis revealed that the M5 samples exhibited the optimal compressive strength of 4.01 and 4.22 MPa for the concretes with peanut and sargassum. The thermal conductivity was lower than 0.37 W/mK, representing a reduction of approximately 75% compared to a conventional mortar. This demonstrates that the appropriate dosage of the compound allows for attaining optimized properties for non-structural applications in buildings.