Some oligo-or polyamides containing several hydroxyl groups were synthesized in order to obtain new water-soluble compounds with a high affinity for polar materials as wood, paper, and natural fibers. The interest for the synthetic procedures is the use of renewable sources as starting compounds. In fact natural compounds or their derivatives, as L-tartaric acid, D(þ)-glucaric acid and a,a-trehaluronic acid, were used as dicarboxylic acids in the polycondensation reactions, in order to obtain several functionalized oligoamides. All the compounds obtained in this study were characterized through FTIR and NMR spectroscopy. The oligoamides, water-soluble and not provided with high-molecular weights, were tested as wood consolidants. Physical properties like hygroscopicity of stabilized wood, volume shrinkage, density, and basic density were evaluated on the treated samples and compared with those obtained in the same conditions for an untreated archeological sample and a recent wood sample.
Crosslinkable cellulose ethers as allyl cellulose, allyl carboxymethyl cellulose, and allyl n-hydroxypropyl cellulose were synthesized and characterized, and their use as consolidating agents for waterlogged wood was studied. For this kind of application, structural properties similar to those of wood's polysaccharide components are desired in the design stage of new consolidants. The choice to synthesize cellulose ethers was determined from the possibility of using cellulose as the starting material because of its large availability in nature, biocompatibility, and low cost. In addition, cellulose ethers are quite easy to obtain, and they can have different properties, depending on the nature and the amount of the functional groups introduced. For this purpose, a cellulose with a lower degree of polymerization was also used for the synthesis of related cellulose ethers. By means of Fourier transform infrared spectroscopy, the affinity of the cellulose derivatives for degraded lignin flours was detected. The preliminary results of this study show that these polysaccharide compounds may be proposed as wood consolidating agents.
A new efficient and sustainable method for the transesterification of triglycerides and production of fatty acid alkyl esters in acidic conditions is disclosed. The transesterification process can be extended, with the same efficiency, to methyl, ethyl and n-butyl esters. The method utilizes chlorotrimethylsilane as the mediator for the transesterification process, with a slight excess of the alcohol reagent and a low temperature (60 uC), without the use of water in any step of the process. The reaction provides a perfect separation of the glyceric phase and the fatty acid alkyl esters, which can be recovered, starting from pure vegetable oil, with high conversion and high purity. The method was positively extended to animal fats, exhausted vegetable oils and highly acidic oils without any pretreatment.
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