PhD defence: Allan de Amorim dos Santos
Allan de Amorim dos Santos defends his thesis,
Approach of new coating formulations based on cationic starch for kraftliner paper
Supervisors:
Associate Professor Anand Ramesh Sanadi, IGN
Professor Gustavo Henrique Denzin Tonoli, Univ. Federal de Lavras - Brazil
Assessment Committee:
Associate Professor Lina Bufalino, Univ. Federal Rural da Amazônia - Brazil
Professor Sergio Henrique Pezzin, Univ. do Estado de Santa Catarina - Brazil
Professor Lisbeth Garbrecht Thygesen (chair UCPH), IGN
Dr. Maria Lucia Bianchi (main chair) - Univ. Federal Rural da Amazônia - Brazil
Dr. Juliana Cristina da Silva – Klabin S.A.
Dr. Saulo Rocha Ferreira - Univ. Federal Rural da Amazônia - Brazil
Dr. Luiz Eduardo Silva - Unicesumar
Summary:
Traditional packaging materials are based on polyethylene and polypropylene, which are not biodegradable and compromise their disposal or recycling. The coating technique on kraftliner paper can improve its barrier properties, decreasing its hygroscopicity and pressure in the environment. Thus, making the coating with natural or biodegradable materials, such as starches, is preferable. Therefore, this work aimed to evaluate cationic starch-based coatings on kraftliner paper to create high-quality multilayer papers with biodegradation and recycling potential and barrier properties. Thus, cationic starch suspensions were mixed with carnauba wax and poly(vinyl alcohol) (PVOH) in proportions of 1:0, 3:1, 1:1, 1:3, and 0:1 (m:m), and also adding bentonite in the proportions of 5%, 7% and 10% (m/m). Then, the treatments were compared with uncoated kraftliner papers (86±1 g/m²). The suspensions were evaluated for solids content, pH, and viscosity, while the films were analyzed by Raman spectroscopy. Formed by two layers of 15.0±0.5 g/m² total, we analyzed the multilayer papers for chemical, physical, morphological and mechanical characteristics. In addition, barriers to water, water vapor, oil, and oxygen were evaluated. The cationic starch proved to be hydrophilic and an efficient oil barrier. The incorporation of carnauba wax, bentonite, and PVOH into the starch also contributed to the barrier properties to water vapor and oxygen. This thesis collaborates with supporting data for future theoretical work. We expect to increase the understanding of sustainable materials and cationic starch to establish a healthier interaction between people and the environment, developing more sustainable packaging for a better future.
A digital version of the PhD thesis can be obtained from the PhD secretary Anne Marie Faldt at anmf@ign.ku.dk