Preparation of methacrylate polymer nanocomposites with cellulose

Polimerni kompoziti predstavljaju skupinu materijala vrlo široke primjene koji omogućavaju napredak u brojnim područjima kao što su ambalažni materijali, folije, filmovi, zatim konstrukcijski materijali i slično. Nanoceluloza, jedan od prirodnih i obnovljivih polimera čijom se upotrebom pridonosi zaštiti okoliša, postaje popularna zbog jednostavne mogućnosti primjene i dobrih svojstava. Koristi se kao punilo u sintetskom polimeru s ciljem da ga zamijeni u što većem udjelu i ujedno ne pogorša njegova svojstva. Cilj ovog rada je prirediti polimerne kompozite na osnovi kopolimera metil-matakrilata i funkcionalnih metakrilata s kristalnom nanocelulozom i ispitati im glavna svojstva. Kopolimerizacija je provedena u zelenom otapalu dobivenom iz obnovljive biomase. Dihidrolevoglukozenon, koji je korišten u ovom radu te poznatiji pod nazivom CyreneTM, potpuno je biorazgradivo otapalo dobiveno pirolizom iz celuloze. U polimerizaciji su dobivene visoke konverzije monomera, te visoke molekulske mase i razmjerno niska polidisperznost kopolimera. Temperatura staklastog prijelaza polimernih nanokompozita se povećava s povećanjem udjela celuloznih nanokristala. Modul elastičnosti kompozitnih materijala je nešto veći ili manji u odnosu na čisti kopolimer i nema značajan utjecaj na primjenska svojstva. Utjecaj na prekidnu čvrstoću kopolimera dodatkom celuloznih nanokristala nije velik osim kod kopolimera metil-metakrilata s hidroksietil-metakrilatom. Istraživanjem je potvrđeno da se upotrebom zelenog otapala i celuloze kao punila mogu proizvesti polimerni materijali veće obnovljivosti i sa znatno manjim štetnim utjecajem na okoliš.Polymer composites present a group of materials that have very wide use and provide improvement in many areas such as materials for packaging, foils, films, construction materials and others. Nanocellulose, one of the natural and renewable polymers that contribute to environmental sustainability, is becoming very important because of its easy application possibilities and good properties. It is used as a filler in a synthetic polymer and it aims to replace it in the largest quantity possible and thereby does not worsen its properties. The purpose of this work is to prepare polymer composites based on the methyl methacrylate copolymer and functional methacrylates with crystal nanocellulose and to test their main properties. The copolymerization was conducted in a green solvent obtained from renewable biomass. Dihydrolevoglucosenone, which was used in this work, also known as CyreneTM, is a completely biodegradable solvent obtained through pyrolysis from cellulose. In the polymerization high conversions of the monomers, high molecular weights and low polydispersity are achieved. The glass transition temperature of the polymer nanocomposites increases with an increased addition of cellulose nanocrystals. The modulus of elasticity of composite materials is slightly higher or lower in regard to the pure copolymer and does not have a significant impact on the application properties. The influence on the breaking strength of the copolymer with the addition of cellulose nanocrystals is not big except for the copolymer methyl methacrylate with hydroxyethyl methacrylate. The research confirmed that by using a green solvent and cellulose as a filler, polymer materials can be produced with higher renewability and the harmful impact on the environment is significantly lesser