Study of functional biofilms as coating in multilayer panels for use in agroindustrial facilities

Author(s)

Erika Yukari Nakanishi

• Document type: Doctoral Thesis
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2018-01-15

Examining board members

Holmer Savastano Júnior; Sérgio Brazolin; Juliano Fiorelli; Francisco Antonio Rocco Lahr; Danilo Florentino Pereira; Sérgio Francisco dos Santos

• Advisor: Holmer Savastano Júnior; Valdemir dos Santos

Abstract

This project aims the study of surface coatings with polymeric films based on latex and rosin, by using a microbicide agent of\' silver in multilayer panels of sugarcane bagasse reinforced with bamboo particles (PMBB) to be used as an insulate material in agroindustrial facilities subject to humid environments with high bacterial load. This project was conducted into four steps. In the step 1 (Study of the multilayer panels), the evaluation of two different molding procedures was conducted, with molding 1 (PMBB-M1) with pre-pressing in the layers and molding 2 (PMBB-M2) without pre-pressing in the layers. Physical and mechanical properties of the PMBB-M2 panel presented better physical and mechanical performance due to the best interaction between the layers compared to the PMBB-M1 panel. In the step 2 (Study of the superficial treatment of panels), it was studied the production and characterization of the films of rosin, latex-LT and latex-LS, as well as the evaluation of the PMBB panel covering, and evaluation of the durability of these panels exposed to weather conditions (sun, rain, wind and dew). The films presented good physical performance, making it difficult to penetrate water in the material, on the other hand, by exposing the materials to radiation and weather conduction it was noticed the degradation of the films, despite the fact that latex-LT and rosin presented better mechanical performance until three months of age. In the step 3 (Study of impregnation of silver nanoparticles (AgNPs) in the films) it was conducted the preparation and evaluation of the films with AgNPs. By means of the microbiology analyses it was stated that the latex-LT and rosin presented bacteriostatic character. In the step 4 (Application of PMBB panels in Poultry facilities) it was evaluated the potential of the PMBB panel as an insulation material in a pig-farm as a piglet shelter. In this step, the microclimate generated inside of the pig shelter heated by incandescent lamps was evaluated through the collection of environmental data and evaluation of the thermal comfort indices. The panel presented good performance, taking into account the temperature and humidity range of thermal comfort for the piglets in the first week of life. Therefore, it can be concluded that the films of rosin and latex-LT in the PMBB panel, promoted a waterproofing of the materials and due to the bacteriostatic character, it was noticed that proliferation of the bacteria when in contact with the films was avoided, thus, the application of this material as thermal insulation in pig installation presents a great potential, due to the coating in the material and propitiates its application in a humid environment and with bacterial load. (AU)

• FAPESP's process: 16/07372-9 - Particleboard based on biomaterials with functional gradation for using as piglet shelter
• Grantee: Erika Yukari Nakanishi
• Support Opportunities: Scholarships in Brazil - Doctorate