Categories: BGNews Date: юни 4, 2018 Title: Общ семинар №19
Rheology and processing of polymer nanocomposites with graphene and other 2D materials
Dr. Ricardo Andrade
Mack Graphe Centre, University Mackenze, Sao Paolo, Brazil
Семинарът ще се проведе на 5 Юни 2018 г. (вторник) от 13.00 ч. в зала 200 на 4 блок на БАН (Институт по механика) Доц. Румен Кръстев секретар на общия семинар на ИМех
Summary: Bi-dimensional (2D) nanomaterials became of great interest, scientific and technologically, due to their unique properties, after graphene was isolated in 2004. These unique properties make them extremely appealing to process polymer nanocomposites, due to their polymer-nanofiller interactions. These nanocomposites have been found to possess promising properties such as mechanical, barrier, thermal, and electrical. These properties are advantageous for applications in the field of food packaging, automotive, airplane, sport products, textile, electronic devices, membranes, and coatings/inks. Among the different methodologies of incorporate 2D nanofillers in a polymer matrix, melt blending is usually the most economical and industrial approach when compared with others. However, the effective reinforcement of polymers is still a challenge due to the poor dispersion and the strong interfacial adhesion between the nanofiller and the polymeric matrix.
In this study, we used different strategies to disperse 2D materials into polymer matrix by using a twin screw extruder. The influence of the methods, processing parameters, particles concentration, level of particles dispersion and polymer nanocomposite properties were evaluated with the aim to understand the thermodynamics and the physical-chemical interactions that are involved in the mixing and dispersion process, with special attention to the rheological properties. Actually, it was observed these particles have a significant influence depending on their preparation and pre-exfoliation, which influences the nanocomposites rheological behavior. Depending on their exfoliation level, they can behave as a lubricant, where the viscosity decreases with the particles. The results showed that the strategies used here to prepare polymer nanocomposite are very efficient in order to obtain a good dispersion, and consequently, obtaining of a material with excellent properties at very low content (some cases less than 0.5% w/w).