Abstract:
This disclosure provides a polymer composite including a polymer, nanocellulose, and a compatibilizer, wherein the nanocellulose comprises cellulose nanocrystals and/or cellulose nanofibrils, and wherein the compatibilizer comprises a maleated polymer. In some embodiments, the nanocellulose includes lignin-coated nanocellulose. The polymer may be selected from polyethylene, polypropylene, polystyrene, polylactide, or poly(ethylene terephthalate). The maleated polymer may be selected from maleated polyethylene, maleated polypropylene, maleated polystyrene, maleated polylactide, or maleated poly(ethylene terephthalate. Other variations provide a process for compatibilizing a polymer with nanocellulose, comprising: providing a polymer; providing nanocellulose comprising cellulose nanocrystals and/or cellulose nanofibrils; providing a maleated polymer; and combining the polymer, the nanocellulose, and the maleated polymer, wherein the maleated polymer functions as a compatibilizer between the polymer and the nanocellulose.
Abstract:
A method for fibrillation of cellulose includes the following steps: introducing fiber pulp of anionic cellulose at a consistency of 1 to 4% into a homogenizer, and homogenizing fiber pulp in the homogenizer at a pressure of 200 to 1000 bar, advantageously 300 to 650 bar, and by using 2 to 4 passes through for the same fiber pulp under these conditions, and after passes through, taking pulp from the homogenizer, which pulp has been fibrillated by homogenization to a degree than can be expressed as Brookfield viscosity exceeding 10,000 mPa·s (consistency 0.8%, 10 rpm).
Abstract:
In accordance with some embodiments of the present invention, a composite material is prepared by blending a flame retardant modified cellulosic nanomaterial (FR-CN) filler into a polymer, wherein the FR-CN filler comprises a cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs)) having a surface functionalized to incorporate a phosphorus-containing moiety. In some embodiments, the FR-CN filler is prepared by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a halogenated phosphorous-containing monomer (e.g., diphenyl phosphoryl chloride). In some embodiments, the surface of the cellulosic nanomaterial is further functionalized to incorporate an orthogonal functionality selected to enhance the compatibility of the FR-CN filler with the polymer by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a monomer (e.g., epichlorohydrin when the polymer is an epoxy-based polymer).
Abstract:
In a method for preparing nanofibrillar cellulose, fibrous dispersion of ionically charged cellulose is repeatedly passed through a mechanical process of disrupting fibers into fibrils until the viscosity starts to decrease. The number average diameter of the nanofibrillar cellulose after the mechanical process is in the range of 2-10 nm, and the zero-shear viscosity is below 10 Pa·s, preferably below 1 Pa·s, when measured in the concentration of 0.5 wt-%. The nanofibrillated cellulose is low aspect ratio nanofibrillated cellulose (NFC-L).
Abstract:
The present invention relates to a haemostatic patch comprising a porous layer based on oxidized cellulose and a neutralized film based on chitosan, said film comprising a free face and a face fixed on one of the faces of the porous layer, and to the method of preparing said patch comprising the following steps: —a°) preparing a porous layer based on oxidized cellulose, —b°) preparing a film based on chitosan starting from an acidic aqueous solution of chitosan, —c°) fixing the film obtained in b°) on one face of the porous layer, —d°) neutralizing the film obtained in b°), —where step c°) can be carried out before or after step d°), characterized in that: the neutralizing step d°) comprises treatment of said film with a neutralizing composition comprising at least ethanol and ammonium hydroxide (NH4OH).
Abstract:
The present disclosure relates to a process for reducing particle agglomeration and/or increasing porosity of agglomerated particles, a method for enhancing dispersion of nanoparticles in a polymer matrix, and thermoplastic or thermoset nanocomposites comprising nanoparticles.
Abstract:
A process for dissolving modified cellulose includes contacting modified cellulose solution with at least one multivalent cation to form a plurality of modified cellulose particles.
Abstract:
A method of recovering purified partly-hydrolyzed cellulose (36) from a composition (14) comprising partly-hydrolyzed cellulose and an acid, such as sulfuric acid. A base (28) having a cation that forms a precipitate with the anion of the acid is added to the composition. For example, a base such as barium hydroxide is added to form a sulfate precipitate. The precipitate (38) is then separated from the partly-hydrolyzed cellulose (36), thus reducing its acid content. The method may include additional steps of centrifugation (18) of the composition, breaking-up agglomerations (44) in the composition after precipitation, and dialysis (42).
Abstract:
A new approach is conceived for the development of organic polymeric conducting materials synthesized from nanocomposites of nanocrystalline cellulose (NCC) and polyaniline (PANI). The process involves oxidative-radical polymerization of aniline in the presence of NCC using either in situ or emulsion polymerization. The resulting NCC-PANI nanocomposite material can be obtained in film or powder form and exhibits electrical conductive properties typical of semiconducting materials. Unlike PANI, a brittle conductive polymer, NCC-PANI nanocomposite materials can be engineered to possess significant flexibility, strength and/or hardness as a result of the NCC acting as a reinforcing scaffold. Depending on the preparation conditions, electrical conductivities for the NCC-PANI nanocomposite materials prepared according to this disclosure range from 9.98×10−5 to 1.88×10−2 S·cm−1; they could also have hardness ≧0.189 GPa or be formed into flexible films of tensile strength of the order of 9.74 MPa and stretch of the order of 0.54%. These unique electrical and mechanical properties render these materials suitable for use in a variety of value-added industrial products, such as batteries, electronics, electrical sensors, separation membranes, anti-static coatings for aerospace applications, as well as anti-corrosive coatings for automotives and other industrial applications.