Wood, a largely used material for the accomplishment of several kinds of objects, is subject in his lifetime to various types of degradation which reduce its chemical and mechanical stability. In detail, water and biological agents can favour hydrolysis reactions which cause the loss of the so-called “olocelluloses” (hemicelluloses and cellulose), which represent the backbone of the wood structure. Aim of this study is the synthesis and characterization of some novel compounds characterized by a structural affinity for the natural wood components as cellulose and hemicelluloses, with the goal of structure consolidation with no alteration of aesthetic characteristics. To restore cellulose-type polysaccharides components, two different types of compounds have been designed and synthesized: water-soluble polysaccharides obtained from cellulose etherification reactions and oligosaccharides obtained from polycondensation reactions applied to glucosidic monomer derivatives opportunely functionalised. The synthesis of polysaccharides derivatives have been carried out in homogeneous phase, using N,N-dimethylacetamide/LiCl as a solvent for cellulose , . In a second time, starting from cellulose samples partially hydrolyzed, it has been possible to obtain polysaccharides with a lower DP, in order to enhance wood-penetration ability of the synthesized molecules. Some tests carried out on archaeological wood flours have shown a good interaction of some of the synthesised compounds with wood residual components. For oligosaccharides derivatives synthesis it has been necessary, at first, to design and carry out the synthesis of a glucosidic monomer able to give polycondensation reactions in a subsequent time. Oligosaccharides obtained with this method, although not provided with high molecular weights, can be employed in applications for planning a wood restoration or consolidation. All the compounds obtained in this study have been characterized through FT-IR spectroscopy, 1D (1H, 13C) and 2D (gCOSY, gHSQC, gHMBC) NMR spectroscopy.
Synthesis and characterization of oligo- and polysaccharides for their use in wood conservation / G.Cipriani; A.Salvini; D.Buralli; C.Nativi; P.Baglioni. - STAMPA. - (2006), pp. L02-L02. (Intervento presentato al convegno 3rd European Students Conference on Physical, Organic and Polymer Chemistry” tenutosi a Vienna, Austria nel 18-20/09/2006).
Synthesis and characterization of oligo- and polysaccharides for their use in wood conservation
SALVINI, ANTONELLA;NATIVI, CRISTINA;BAGLIONI, PIERO
2006
Abstract
Wood, a largely used material for the accomplishment of several kinds of objects, is subject in his lifetime to various types of degradation which reduce its chemical and mechanical stability. In detail, water and biological agents can favour hydrolysis reactions which cause the loss of the so-called “olocelluloses” (hemicelluloses and cellulose), which represent the backbone of the wood structure. Aim of this study is the synthesis and characterization of some novel compounds characterized by a structural affinity for the natural wood components as cellulose and hemicelluloses, with the goal of structure consolidation with no alteration of aesthetic characteristics. To restore cellulose-type polysaccharides components, two different types of compounds have been designed and synthesized: water-soluble polysaccharides obtained from cellulose etherification reactions and oligosaccharides obtained from polycondensation reactions applied to glucosidic monomer derivatives opportunely functionalised. The synthesis of polysaccharides derivatives have been carried out in homogeneous phase, using N,N-dimethylacetamide/LiCl as a solvent for cellulose , . In a second time, starting from cellulose samples partially hydrolyzed, it has been possible to obtain polysaccharides with a lower DP, in order to enhance wood-penetration ability of the synthesized molecules. Some tests carried out on archaeological wood flours have shown a good interaction of some of the synthesised compounds with wood residual components. For oligosaccharides derivatives synthesis it has been necessary, at first, to design and carry out the synthesis of a glucosidic monomer able to give polycondensation reactions in a subsequent time. Oligosaccharides obtained with this method, although not provided with high molecular weights, can be employed in applications for planning a wood restoration or consolidation. All the compounds obtained in this study have been characterized through FT-IR spectroscopy, 1D (1H, 13C) and 2D (gCOSY, gHSQC, gHMBC) NMR spectroscopy.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
