Cellulose derivatives still receive special attention in today biomedical applications due to their biocompatibility, ability to form resistant membranes and compatibility with various bioactive agents. In this work, cellulose acetate (CA) was used to prepare membranes with different morphologies aiming to evaluate the release profile of the drug ibuprofen (IBF). The IBF incorporation was performed by the addition of 10% of the drug in an 8% (w/w) CA/acetone solution. The morphology of the membranes was modified by the addition of water, used as porogenic agent. Drug release assays showed the effect of morphology on the cumulative drug release curves. The symmetric membrane exhibited retention of significant amounts of the drug and a slow release process that lasted for more than 50 hours. The asymmetric porous membranes presented different behavior with greater amount of drug released in less time of release. The kinetic parameters calculated from the Higuchi and Korsmeyer/Peppas models indicated release profiles controlled by diffusion/solution process in the polymer matrix. The results revealed that the interactions established between IBF, CA and the matrix morphology are significant factors for the kinetic control of the drug release process and enable to choose different applications of the membranes loaded with IBF.

Methylcellulose was produced from the fibers of Mangifera indica L. Ubá mango seeds. MCD and MCI methylcellulose samples were made by heterogeneous methylation, using dimethyl sulfate and iodomethane as alkylating agents, respectively. The materials produced were characterized for their thermal properties (DSC and TGA), crystallinity (XRD) and Degree of Substitution (DS) in the chemical route. The cellulose derivatives were employed as mortar additive in order to improve mortar workability and adhesion to the substrate. These properties were evaluated by means of the consistency index (CI) and bond tensile strength (TS) tests. The methylcellulose (MCD and MCI) samples had CI increased by 27.75 and 71.54% and TS increased by 23.33 and 29.78%, respectively, in comparison to the reference sample. Therefore, the polymers can be used to produce adhesive mortars.

In the present paper, the use of poly(styrene sulfonate) (PSS), produced from discarded polystyrene materials through heterogeneous and homogeneous processes, was investigated. The use of PSS for water treatment, using a kaolin suspension as wastewater model, reduced water turbidity for all the employed materials when compared to the blank analysis, without PSS. The most efficient polyelectrolyte was PSS cups obtained by homogeneous route. The same behavior was observed for real system. The homogeneous PSS cups showed a balance between a moderate molecular weight and high anionic character that improved flocks formation and water removal turbidity.