Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
  • C04B28/10—Lime cements or magnesium oxide cements
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/91—Use of waste materials as fillers for mortars or concrete

Definitions

• the invention relates to an organo-mineral complex obtainable by chemical degradation of cellulose, a process for producing such a complex and the applications thereof, in particular in construction.
• Cellulose the most abundant organic polymer in the biosphere, is a polysaccharide made up of glucose units connected by ⁇ (1-4) bonds, the number of which can reach several thousand. It is a linear polymer whose linking gives it a secondary structure which can be assimilated to a helix consisting of dimeric units of cellulobiosis at each step of the helix, and whose tertiary structure is a bundle of polysaccharide chains arranged. parallel to each other and in the same direction from the non-reducing end to the reducing end, forming microfibrils. In this structure come into play a considerable number of intramolecular and intermolecular hydrogen bonds, at the origin of the remarkable mechanical strength of cellulose.
• FR2700163A1 discloses a process for the manufacture of a building material which is obtained by a reaction mixture comprising a suspension of cellulosic fibers from waste paper and cardboard, lime and a mono- or trivalent sulfate of metal salts like aluminum, in stoichiometric quantities.
• a reaction mixture comprising a suspension of cellulosic fibers from waste paper and cardboard, lime and a mono- or trivalent sulfate of metal salts like aluminum, in stoichiometric quantities.
• Such conditions lead to the formation of a calcium ligno-sulphoaluminate in the form of a paste which is pressed and then dried, or molded, and is then used to manufacture a structural element having mechanical and sound and thermal insulation properties.
• the Applicant has developed a method of chemical degradation of cellulose using quicklime, not hydrated lime, resulting in an organo-mineral complex different from those known.
• This complex possesses exceptional mechanical and physicochemical properties which
• the material of the invention makes it possible to obtain more efficient construction elements, as some of the properties of such elements, listed below:
• the invention relates to a calcio-cellulosic organo-mineral complex that can be obtained by reaction of quicklime on cellulose, in aqueous suspension.
• quicklime reacts with cellulose at a much higher rate than the hydration of quicklime in the aqueous medium, but the two reactions, having different kinetics, co-exist.
• a complex is formed, that of the invention, which consists of polysaccharide chains resulting from a rupture of the intermolecular hydrogen bonds of cellulose and a decarboxylation of the CH 2 OH group (carbon 6) carried by the carbon 5 of the units.
• glucose of cellulose associated with calcite CaCO 3 . This is formed by the reaction of the carbon dioxide released by said decarboxylation on Ca (OH) 2 from the hydration of quicklime in the reaction medium.
• the intermolecular hydrogen bond breaking and decarboxylation of the CH 2 OH group carried by the carbon 5 of glucose units may be concomitant.
• At least 50% of the non-reducing ends of the cellulose are decarboxylated according to the decarboxylation described above, preferably at least 75%, or even at least 90%, or even all.
• at least 50% of the intermolecular hydrogen bonds of the cellulose are broken, preferably at least 75%, or even at least 90%, or even all.
• Decarboxylation of the CH 2 OH group carried by the carbon of the glucose units requires the rupture of the intramolecular hydrogen bond between the hydrogen atom of the C6 hydroxyl group of the glucose unit concerned by the decarboxylation, and the atom of oxygen from the pyranic ring of the next glucose unit. During complex formation, other intramolecular hydrogen bonds can also be broken, without subsequent decarboxylation.
• the invention also relates to a process for the preparation of a calcio-cellulosic complex, in which aqueous lime is reacted in aqueous suspension on cellulose and the complex is obtained in the form of a paste.
• the cellulose to be treated can be in any form, pretreated or not, and come from any source. It is preferably in the form of cellulose fibers, it can come from all papermaking waste and cardboard, such as cellulosic waste from recycling, landfills, waste paper, cardboard, newspapers, magazines or other cellulosic waste. It can also come from paper sludge or waste paper.
• the implementation of the process is simple, and the complex is obtained regardless of the order of addition of the ingredients, namely, water, quicklime and cellulose. Their addition may be concomitant.
• quicklime is poured into water and the cellulose is then introduced.
• the weight ratio of CaO to cellulose is preferably between 30/70 and 70/30.
• it is 50/50, the amount of quicklime reacted being the same as that of the cellulose to be treated.
• various ingredients may be added, depending on the desired applications, such as a salt of a metal chosen from aluminum, potassium, magnesium and calcium, the salt being preferably chosen from sulphates, phosphates, carbonates, oxalates and silicates, or calcium stearate, alumina, cellulose powder, sawdust and / or calcium silicate.
• a salt of a metal chosen from aluminum, potassium, magnesium and calcium the salt being preferably chosen from sulphates, phosphates, carbonates, oxalates and silicates, or calcium stearate, alumina, cellulose powder, sawdust and / or calcium silicate.
• the complex of the invention has applications in many other industrial fields, such as in furniture, for example in the manufacture of furniture, objects or decorative panels, such as in the civil engineering and public works sector, for example as filling mortar, laying and jointing mortar, as a material for the manufacture of road panels, for the manufacture of pavers and curbs.
• objects or decorative panels such as in the civil engineering and public works sector, for example as filling mortar, laying and jointing mortar, as a material for the manufacture of road panels, for the manufacture of pavers and curbs.
• Figures 1-5 show the infrared spectra of a control cellulose, a complex of the invention and the superposition of these spectra with others of chemical entities likely to be found in one or both samples
• Figures 6 and 7 show the X-ray diffraction spectra of the cellulose control and a complex of the invention.
• Example 1 Process for the Preparation of an Organo-mineral Complex of the Invention
• the complex is prepared from cellulosic waste from recycling, landfills, waste paper, cardboard, newspapers, magazines or other cellulosic waste. It could just as easily be made from paper sludge or waste paper.
• Infrared spectroscopy in total reflection attenuated on diamond crystal was performed on a sample of paste obtained according to the invention in Example 1 and a starting cellulose sample obtained by dispersing the starting waste in water, said cellulose control, for comparison.
• the IR spectra are shown in FIG. 1 for the cellulose control, and 2 for the paste of example 1.
• FIG. 3 is superimposed on the spectrum of FIG. 1 (cellulose control), the spectra of cellulose, calcite (calcium carbonate) and kaolinite (hydrated aluminum silicate, of formula AI 2 Si 2 0 5 (OH) 4 ) from the spectral libraries of the analysis laboratory.
• FIG. 4 the same spectra of calcite and kaolinite are superimposed on the spectrum of FIG. 2 (invention) as in FIG.
• FIG. 5 the spectra of FIGS. 1 and 2 are superimposed.
• FIGS. 1 and 3 show the following characteristic bands:
• FIGS. 2 and 4 show the following characteristic strips:
• the analyzes were performed on a 40-300 kV X-ray beam dosimeter apparatus, at a wavelength of 1.5406 nm.
• FIG. 6 shows the X-ray diffraction spectrum of the cellulose control.
• FIG. 7 shows the X-ray diffraction spectrum of the calcio-cellulosic complex of the invention of Example 1.
• This calcite is formed by a reaction of the carbon dioxide released during the exothermic reaction of quicklime on cellulose, the pyranic cycle on Ca (OH) 2 from the hydration of quicklime in the reaction medium.
• Example 1 The calcio-cellulosic complex obtained in Example 1 in paste form has many applications, some of which are hereinafter illustrated.
• compositions based on a paste of the invention and cement is prepared in proportions to be determined according to the desired result, and then calcium or zinc stearate is added in a proportion 0.1 to 0.5% (w / w) as a water repellent.
• the composition thus prepared can be projected.
• the paste of the invention is dried to obtain a powder, which is then mixed with cement, in proportions to be determined according to the desired result.
• a powder In the form of a powder, it can be added as an adjuvant for the preparation of a cement or a plaster to be tempered, which can in particular be used for the manufacture of a building element or panel having a high power of thermal and sound insulation.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)

Applications Claiming Priority (1)

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• 2014
  • 2014-07-24 WO PCT/FR2014/051929 patent/WO2016012662A1/fr active Application Filing
  • 2014-07-24 EP EP14750776.8A patent/EP3172179A1/fr not_active Withdrawn
  • 2014-07-24 CN CN201480080895.2A patent/CN106660880A/zh active Pending

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