Granular starches grafted with polycaprolactone (St-g-PCL) were obtained using N-methylimidazole (NMI) as a catalyst. The effect of the starch/monomer ratio and catalyst content was studied to obtain different levels of grafted PCL. The highest grafting percentage (76%) and addition (43%) were achieved for reactions with a starch/monomer ratio of 50/50 and 25% catalyst. The grafting of PCL on the starch granule was verified by the emergence of the carbonyl group in the FTIR spectra and the increased diameter of the grafted starch granule. Thermoplastic starch from ungrafted starch (TPS) and grafted starch (TPGS) was obtained by mixing ungrafted or grafted starch granules with water, glycerol, or sorbitol in a mixer. TPS and TPGS behave as plastic materials, and their mechanical properties depend on the type of plasticizer used. Materials with glycerol as the plasticizer exhibited less rigidity. The presence of starch-g-PCL results in a dramatic increase in the elongation of the thermoplastic material. The starch present in the TPS or TPGS was completely biodegraded while the grafted PCL was partially biodegraded after the enzymatic degradation of the materials.

This work proposes a conceptual design for recovering polystyrene (PS) using solvents of agro-industrial origin. The literature describes the dilution of expanded polystyrene (EPS) in limonene, followed by its insolubilization with alcohols for recovery. However, there is no information on the solubility limit for the PS + limonene + alcohol system, which is critical for the process design. To determine the solubility limit, we diluted the waste EPS in D-limonene, mixed it with ethanol to form a precipitate, and used a gravimetric method to measure the mass of the compounds. These results allowed for the conceptual design of an EPS recycling process using a chemical process simulator, which includes a separator, a distillation column, and auxiliary equipment such as heaters, coolers, and pumps. An empirical correlation was obtained for the solubility limit, which enabled the design of a process for the treatment of 52 kg/s of PS using 0.75 kg/s of ethanol and 2.4 kg/s of D-limonene once the stationary state had been reached. The distillation column is six-stage, with a reflux ratio of 1.5 and duties of 30,000 and −25 847 kW for the condenser and reboiler, respectively.

El sector agropecuario en Colombia, es considerado primordial para el desarrollo económico del país, las diferentes entidades encargadas de la ejecución de los recursos, hacen esfuerzos para hacer uso eficiente de los mismos mediante diferentes mecanismos estatales, tales como las convocatorias de proyectos cuyas estrategias se operativizan en los departamentos y municipios; sin embargo, se ha observado que para Boyacá, el acceso a los recursos por parte de los agricultores ha sido bajo, además se ve la necesidad de implementar herramientas pertinentes que faciliten el proceso de gestión de los proyectos desde la identificación hasta la ejecución. Dado lo anterior se plantea esta investigación con el análisis de la gestión pública y la relación de los proyectos agropecuarios, a través de la conceptualización y estructura de un modelo que permita identificar y desarrollar sistemáticamente el paso a paso para la gestión de proyectos agropecuarios. Se empleó para el desarrollo de la investigación el método cualitativo y cuantitativo. Los datos surgen progresivamente permitiendo la profundidad en las ideas, se contextualiza el fenómeno y los resultados son particulares. Dentro de los hallazgos encontrados, se observa que las principales limitantes de la gestión de los proyectos están en la deficiente articulación de los actores, la concentración de los proyectos en el 58% de municipios de Boyacá y en la falta de manejo de competencias blandas como trabajo en equipo, comunicación, resolución de conflictos y logros motivacionales.