564results about How to "Reduce the degree of polymerization" patented technology

Strands of molten polyethylene terephthalate (PET) from a PET polycondensation reactor are solidified, pelletized, and cooled only to a temperature in the range of 50° C. to a temperature near the polymer Tg by contact with water. The still hot pellets are conveyed, optionally followed by drying to remove water, to a PET crystallizer. By avoiding cooling the amorphous pellets to room temperature with water and cool air, significant savings of energy are realized.

Coating liquid prepared by dissolving an acid and a silicon alkoxide into alcohol, containing at least one of either a silicon alkoxide or a hydrolyzate thereof (including a partial hydrolyzate) in an amount of 0.010 to 3% by weight (in terms of silica), an acid in terms of 0.0010 to 1.0 normality, and water in terms of 0 to 10% by weight is coated on a substrate to produce an article coated with a silica-based film. By this method for producing a silica-based film coated article, an excellent silica-based film coated article can be obtained without requiring baking and pretreatment. Furthermore, a functional film coated article excellent in durability can be produced in a short period of time and safely by using the abovementioned silica-based film as a primer film and applying thereon an organosilane having a hydrolyzable group and a functional group having a specific function or a hydrolyzate thereof.

A process for making a composition for conversion to lyocell fiber where the process comprises pulping a raw material in a digester to provide an alkaline pulp, wherein the raw material comprises sawdust in an amount greater than 0 % up to 100 %; and contacting the alkaline pulp comprising cellulose and at least about 7 % hemicellulose under alkaline conditions with an amount of an oxidant sufficient to reduce the average degree of polymerization of the cellulose to within the range of from about 200 to about 1100, without substantially reducing the hemicellulose content of the pulp or substantially increasing the copper number.

The present invention provides a process for the preparation of high molecular weight crystalline Polyethyleneterephthalate (PET) using up to 50% of Post consumer recycled PET flakes along with Pure Terephthalic Acid (PTA), Isophthalic Acid (IPA) and Mono Ethylene Glycol (MEG) as a virgin raw material, in the presence of a combination of catalysts and additives to obtain an intermediate prepolymer heel having a low degree of polymerization further subjecting to autoclaving to yield an amorphous melt and followed by solid state polymerization.

The invention discloses a method for preparing water-soluble solid styrene / acrylic resin and application thereof. The method prepares the required resin by simultaneously performing free radical polymerization reaction and esterification reaction on an aromatic vinyl unsaturated monomer, an aliphatic vinyl unsaturated monomer, an unsaturated carboxylic acid monomer, fat alkanol, an initiating agent and an alpha-methyl styrene dimer in a reactor. In the method, the alpha-methyl styrene dimer is added as a chain transfer agent to reduce the branching degree and avoid the generation of gel and the blockage of the reactor; and simultaneously, the added fat alkanol performs esterification reaction with acroleic acid to inhibit the esterification reaction between an alcohol ether solvent and the acroleic acid, thus the viscosity of the reaction mixture is controlled effectively, and the finally prepared resin has narrow molecular weight distribution (Mw / Mn is less than 2.0), low molecular weight (Mw is less than 10,000), few organic volatile matters, and good wetting dispersion of pigment, and can be applied to preparing water color ink, coating or oil polish.

The invention discloses a composite material for pultrusion polyurethane resin and a preparation method thereof. The composite material is prepared from continuous fiber and polyurethane resin; the continuous fiber is selected from glass fiber or carbon fiber and is 60-85% of the total volume of the composite material in percentage by weight; and the polyurethane resin is 15-40% of the total volume of the composite material in percentage by weight. The resin disclosed by the invention has fast speed during curing, high degree of cross-linking, excellent mechanical property and good wettability to fiber reinforced materials.

PCT No. PCT / JP97 / 01785 Sec. 371 Date Mar. 16, 1998 Sec. 102(e) Date Mar. 16, 1998 PCT Filed May 26, 1997 PCT Pub. No. WO97 / 45452 PCT Pub. Date Dec. 4, 1997The purpose of the present invention is to provide a simple and economical method for the production of BC having improved properties such as dispesibility, suspensibility and viscosity. The present invention relates to a method for the improvement of dispersibility and suspensibility of bacterial cellulose, comprising concentrating an aqueous suspension of bacterial cellulose to a final concentration of the bacterial cellulose of between 10% by weight or more and less than 75% by weight, dispersing it again into an aqueous solution and homogenizing the bacterial cellulose in the resulting dispersion, to a method for the improvement of paper properties of bacterial cellulose, comprising concentrating an aqueous suspension of homogenized bacterial cellulose to a final concentration of the bacterial cellulose of between 4% by weight or more and less than 75% by weight, dispersing it again into an aqueous solution and homogenizing the bacterial cellulose in the resulting dispersion, and to the BC concentrate thus prepared.

A method for recovering sulfuric acid from concentrated acid hydrolysate of plant cellulose material is disclosed. In some of the examples, the concentrated acid hydrolysate is mixed with a liquid organic precipitant, with the sugars in the hydrolysate being precipitated and separated out. The remainder is sulfuric acid and an organic solvent solution. The organic solvent is then separated by distillation or extraction, thereby obtaining the pure sulfuric acid solution. This precipitation method can recover above 90% sugars and acids with a small amount of organic precipitant, which greatly reduces the recovery cost.

The invention is directed to olefin copolymers composed of nonhydrolyzable monomer units and hydrolyzable monomer units, the latter resulting from copolymerization of monomers containing a linkage that is hydrolytically cleavable in the presence of aqueous base or aqueous acid. Generally, the hydrolyzable monomer units represent a significant fraction of the copolymer, such that upon hydrolysis, a substantial portion of the copolymer is degraded into low molecular weight fragments. Also provided are degradable articles that are at least partially composed of a degradable copolymer in which hydrolyzable monomer units represent at least 20 mole % of the copolymer. These degradable articles include agricultural film products, adhesive tape substrates, bed linens, containers, disposable absorbent articles, packaging materials, bags, labels, pillow cases, protective clothing, surgical drapes, sponges, tampon applicators, disposable syringes, temporary enclosures and temporary siding, toys, wipes, foamed plastic products, and controlled release pellets, strips and tabs.

The present invention provides a process for the preparation of high molecular weight crystalline Polyethyleneterephthalate (PET) using up to 50% of Post consumer recycled PET flakes along with Pure Terephthalic Acid (PTA), Isophthalic Acid (IPA) and Mono Ethylene Glycol (MEG) as a virgin raw material, in the presence of a combination of catalysts and additives to obtain an intermediate prepolymer heel having a low degree of polymerization further subjecting to autoclaving to yield an amorphous melt and followed by solid state polymerization.

The invention relates to a resourced recovering and utilizing method for waste cotton fabric, in particular to a technology for recovering polyester and cotton fiber from waste polyester cotton blended fabric and using the polyester and the cotton fiber during the production of fermentable sugar, and belongs to the field of resourced cycling and reutilizing of solid waste. According to the resourced recovering and utilizing method, concentrated phosphoric acid is used as a solvent, a reaction is conducted under the conditions that the mass fraction of the phosphoric acid is 82 to 86 percent, the solid-liquid ratio is 1:10 to 1:30, the reaction temperature is 45 to 60 DEG C, and the reaction time is 2 to 18 hours; the cotton fiber in the polyester cotton blended fabric is completely dissolved, so as to enable the polyester to be isolated and recovered by one hundred percent; then water is added to a solution to dilute the solution, so as to enable cellulose to be regenerated and obtain regenerative cellulose with a low cleanliness degree and a low polymerization degree, which is applicable to enzymatic hydrolysis; and after the regenerative cellulose is subjected to the enzymatic hydrolysis, the fermentable sugar is generated to be used as a carbon source for fermenting and producing bio-based products. Waste liquid is distilled and the concentrated phosphoric acid is recovered to be circularly used. The resourced recovering and utilizing method is applicable to the polyester cotton blended fabric formed in any proportion, has the advantage of relatively low energy consumption and is simple to operate; and the polyester can be recovered by one hundred percent, the concentrated phosphoric acid can be simultaneously recovered to reduce costs, and the cotton fiber component is utilized to produce bio-based sources or bio-based products.

An apparatus for continuous stirring comprising a horizontal elongated cylindrical vessel and two rotating blade assemblies rotatable in the direction opposite to each other provided in parallel to each other in the vessel, where a liquid feed is moved from one end to another therethrough by rotation of the two rotating blade assemblies in the direction opposite to each other, while stirring and mixing the liquid feed, the two rotating blade assemblies each comprising rotor shafts (3a-3b or 3c-3d) supported at both ends of the rotating blade assemblies, support members (4) each fixed to the rotor shafts, connecting members (5) span between the support members (4) and in positions far from the substantial rotating shaft center and a plurality of plate-shaped stirring blades (6) arranged in parallel in the longitudinal direction of the substantial rotating shaft center and fixed to the connecting members (5).

The invention relates to the technical field of production of regenerated cellulose fiber, in particular discloses a complex enzyme preparation applied in the preparation of dissolving pulp and a technique for preparing the dissolving pulp by using the enzyme preparation. The complex enzyme preparation is divided into a complex enzyme preparation I and a complex enzyme preparation II, wherein the complex enzyme preparation I mainly consists of feruloyl esterase, lipase and the like; and the complex enzyme preparation II mainly consists of xylanase, cellulase and the like. The complex enzyme preparation is applied in the technique for purifying alpha-cellulose and preparing the dissolving pulp; and the technique comprises the following steps of impurity removal for raw materials, enzyme method pretreatment, enzymolysis pulping, chelation treatment, alkali hydroxyl active oxygen cooking, acid treatment, washing, sand removal and pulp mixing. The method has the simple preparation technique, and adopts the complex enzyme preparation to treat the raw material pulp so as to effectively remove lignin, hemicellulose, pectin substance and waxiness and to reduce the degree of polymerization of the alpha-cellulose; the energy consumption is low under the normal pressure condition; the COD (Chemical Oxygen Demand) value of the pulping waste water is low; the yield of the dissolving pulp is high; the alpha-cellulose has high content and uniform degree of polymerization; and the production requirements of viscose can be satisfied.