AbstractsChemistry

Cellulose-based materials

by Sara R. Labafzadeh




Institution: University of Helsinki
Department: Department of Chemistry, Laboratory of Organic Chemistry
Year: 2015
Keywords: laboratory of Organic Chemistry
Record ID: 1141964
Full text PDF: http://hdl.handle.net/10138/153410


Abstract

Worldwide research is focused on the use of renewable and biodegradable raw materials due to the limited existing quantities of fossil supplies and the environmental degradation caused by global warming. Cellulose, derived from natural resources such as wood, annual plants and microbes, represents the most abundant renewable polymeric material on earth. Due to its low cost and functional versatility, cellulose has been a key feedstock for the production of chemicals with various properties and applications over the past century. It has found a wide range of applications in food, printing, cosmetics, pharmacy, therapeutics, paper making and in the textile industry. This partly crystalline polymer has not yet reached its full application potential due to its essential insolubility in most common solvents. Many investigations focus on the development of novel media for efficient and economically feasible functionalization of cellulose. The chemical modification of cellulose overcomes this obstacle and offers considerable opportunities for preparing cellulose-based polymeric materials. The modification could adjust the properties of the macromolecule for different purposes and meet the environmental requirements by using green reagents and recyclable solvent systems. Synthesis of new cellulose-based polymers and their thorough characterization and increasing the usefulness of cellulose by altering its properties have been of growing research interest for the past few years. The objective of this research was to investigate new paths for the preparation of cellulose-based materials with a variety of structural features to obtain advanced materials suitable for different applications. Most of the research has focused purely on the synthesis of cellulose derivatives in new and economically feasible solvent systems, but it also has general relevance for the material properties of the obtained derivatives. Also, the potential application of synthesized cellulose derivatives as barrier films for packaging was investigated. Highly substituted cellulose esters, carbamates and carbonates were prepared using various recyclable reaction solvents. Biomaterials with the potential for use in the packaging sector should provide high mechanical properties, in addition to good barrier properties for oxygen and water vapour. Some derivatives showed good barrier properties being promising for packaging application. Uusiutuvien ja biohajoavien raaka-aineiden tutkimus on maailmanlaajuisesti erittäin aktiivista johtuen fossiilisten polttoaineiden rajallisista määristä ja ilmaston lämpenemisen aiheuttamista ympäristön muutoksista. Selluloosaa, maailman yleisintä uusiutuvaa polymeeriä, syntyy luonnossa esimerkiksi puissa ja yksivuotisissa kasveissa sekä myös mikrobien tuottamana. Alhaisesta hinnastaan ja monikäyttöisyydestään johtuen selluloosa on ollut viimeisen vuosisadan aikana yksi tärkeimmistä teollisuuden raaka-aineista. Lukuisia sovelluksia on hyödynnetty mm. elintarvike-, kosmetiikka-, lääke-, paperi-, tekstiili- ja…