Autor(es): Correia, Ricardo Miguel Paulino Barroso Dias
Data: 2013
Identificador Persistente: http://hdl.handle.net/10362/11082
Origem: Repositório Institucional da UNL
Assunto(s): Derivatized sucrose; Biocompatibility; Biodegradability; Conventional synthesis protocols; Microwave assisted protocols; Vinyl esters
Dissertation toobtaina Master of Science degree in Bioorganics
There has been a worldwide acknowledgement that nature derived saccharides can provide the raw materials needed for the production of numerous industrial consumer goods. As such, sucrose is a low molecular weight renewable carbohydrate feedstock from which it is possible to elaborate new materials, like water-soluble and/or amphiphilic and biocompatible polymers. In this thesis we will describe some synthetic procedures (both conventional synthesis protocols (CSP) and microwave assisted protocols (MAPs)) by introducing and altering sugar hydroxyl groups, with the intent to produce functionalized polymers for use as biodegradable/biocompatible polymers with sugar linked side chains. The most widely used method for the synthesis of poly(vinyl saccharide)s has been based on free radical polymerizations of vinyl sugars. In this work, eleven compounds based on sucrose derivatization were synthesized using anhydrides, bromide halides, silyl chlorides, non-selective esterification and Mitsunobu reaction. Optimization and scale-up studies were made on monomer synthesis. Four of these compounds were used as monomers for radical copolymerization with styrene using as catalysts 2,2’-Azobis(2-methylpropionitrile) and sodium persulfate whether organic solvents or water was used as reaction media. From this copolymerization’s, four polymers were obtained and polystyrene was also synthesized to be used as a standard for comparison. The polymers, poly(1’,2,3,3’,4,4’,6-hepta-O-benzyl-6’-O-methacryloyl sucrose)-co-polystyrene, poly(1’,2,3,3’,4,4’,6’-hepta-O-acetyl-6-O-methacryloyl sucrose)-co-polystyrene, poly(6-O-methacryloyl sucrose)-co-polystyrene and poly(O-methacryloyl sucrose)-co-polystyrene, were characterized by Proton nuclear magnetic resonance (to assess sucrose vinyl ester/styrene ratio), Fourier transform infrared spectroscopy, Differential scanning calorimetry, Powder X-ray diffraction, Atomic force microscopy (topology studies as thin films and aggregates), Viscometry and polarimetry.
