13results about How to "Improve melt strength" patented technology

This invention discloses a method for preparing low-density, high-filler SPC flooring. The method is characterized by a raw material formulation comprising the following components in the indicated weight proportions: 100 parts graft-modified PVC resin, 300-350 parts filler, 9-12 parts heat stabilizer, 3-5 parts melt processing modifier, 3-5 parts reinforcing and toughening modifier, 1-2 parts external lubricant, 1-2 parts internal lubricant, 2-5 parts chemical foaming agent, and 2-5 parts foaming aid. The graft-modified PVC resin is prepared by replacing the chlorine atoms in PVC with p-aminothiophenol, followed by an amidation reaction between a diacid or polyacid and an amino group. Its advantages are: 1) It improves the melt strength and expandability of the PVC resin, ensuring foaming performance under high filler content. Compared with ordinary SPC flooring, the flooring product has lower density and lighter weight, higher hardness, and lower overall formulation cost compared to ordinary low-density SPC flooring. 2) The process is simple, and the product has high controllability.

This invention relates to the field of polymer foaming materials technology, and discloses a plant fiber composite nucleating agent for microfoaming of biodegradable materials and its application. The plant fiber composite nucleating agent is made from raw materials comprising the following parts by weight: 80-95 parts of primary ultrafine plant fiber powder, 5-20 parts of surface modifier, and 0.1-5 parts of dispersing lubricating wax; the surface modifier and dispersing lubricating wax are coated on the surface of the primary ultrafine plant fiber powder. The application steps are as follows: adding the plant fiber composite nucleating agent to a biodegradable material matrix to obtain a pre-foaming blend, introducing foaming gas or adding a chemical foaming agent for foaming treatment. The nucleating agent of this invention improves the compatibility between plant fibers and hydrophobic biodegradable matrices, provides heterogeneous nucleation sites in the matrix while increasing the polymer melt strength, inhibits cell coalescence and rupture, and obtains microfoamed materials with uniform pore size. Furthermore, the nucleating agent itself is completely biodegradable.

The application discloses a kind of polylactic acid double-stretching film materials and preparation method thereof, belong to the field of biaxially oriented film.The polylactic acid double-stretching film material includes the following mass fraction of raw materials: polylactic acid 95~99 parts, melt strength improvement aid 1~5 parts, hydrolysis inhibitor 0.3~1 parts and processing aid 0.5~1 parts;Melt strength improvement aid is ultra-high molecular weight polar polymer;Ultra-high molecular weight polar polymer contains one or a combination of two of epoxy group and side chain ester group.The melt strength improvement aid improves the melt strength and melt uniformity of polylactic acid, thereby improving the yield and film thickness uniformity of polylactic acid double-stretching film;The addition of hydrolysis inhibitor improves the heat processing stability of the material, to obtain a kind of processing performance excellent, while taking into account melt strength and uniformity, thickness fluctuation small polylactic acid double-stretching film material.

This invention relates to the field of propylene polymerization, and discloses a polypropylene, its preparation method, and its applications. The polypropylene has a molecular weight distribution of 6-20; at 230℃, a melt index of 0.1-10 g / 10 min with a loading of 2.16 kg; an isotactic index ≥97%; a fraction with a weight-average molecular weight M ≥ 5 million g / mol containing ≥1 wt%, a fraction with 1000 g / mol < M < 50000 g / mol containing 5-30 wt%, a fraction with 50000 g / mol ≤ M < 5 million g / mol containing 60-90 wt%, and a fraction with M ≤ 1000 g / mol containing <1 wt%; a melt strength ≥0.4 N at 230℃; a heat distortion temperature ≥95℃; and a flexural modulus ≥1800 MPa. This polypropylene exhibits high isotacticity, a wide molecular weight distribution, high flexural modulus, and also high melt strength and heat resistance.

This invention discloses a polyester material, a heat-shrinkable film, its preparation method, and its applications. The raw materials for preparing the polyester material include a diacid, a diol, a chain extender, a stabilizer, and a catalyst; wherein the diacid comprises: 90 mol%~95 mol% polyterephthalic acid and 5 mol%~10 mol% isophthalic acid; the diol comprises: 65 mol%~78 mol% ethylene glycol, 18 mol%~28 mol% 1,4-cyclohexanediol, and 4 mol%~12 mol% diethylene glycol; the chain extender is 2,2'-(1,3-phenylene)-dioxazoline, added in an amount of 0.2%~0.8% of the total mass of the diol and the diacid; the molar ratio of carboxyl groups to hydroxyl groups in the diacid and the diol is 1:1~1.05. The polyester material of this invention possesses excellent transparency, shrinkage rate, and strength, and has a low initial shrinkage temperature, making it particularly suitable for applications such as heat-shrinkable films. This invention also provides a heat-shrinkable film, as well as the polyester material, a method for preparing the heat-shrinkable film, and their applications.

The invention relates to the field of propylene polymerization, and discloses a preparation method of polypropylene, polypropylene and application. The method comprises the following steps: S1, in the presence of a functional external electron donor and a catalyst system, carrying out a prepolymerization reaction on propylene to obtain a prepolymer A; the prepolymerization multiplying power is 1000 to 10000 times; s2, in the presence of a first molecular weight regulator, a first external electron donor and the prepolymer A, performing a first polymerization reaction on propylene to obtain a polymer B; s3, in the presence of a second molecular weight regulator, a second external electron donor and a polymer B, carrying out propylene second polymerization reaction to obtain polypropylene. According to the method, the prepolymerization reaction is combined with the polymerization reaction of two stages, the functional external electron donor is introduced in the prepolymerization process, and the specific first external electron donor and the specific second external electron donor are subsequently matched, so that the prepared polypropylene has good processability and heat resistance.

This invention relates to the field of organic synthesis technology, and in particular to a monophosphine halide and its preparation method, as well as a method for preparing polypropylene resin. The monophosphine halide provided by this invention has the following structure: where n is an integer between 1 and 4, and X is selected from any one of F, Cl, Br, and I. The monophosphine halide of this invention has a specific structure, and when used in the polymerization reaction of propylene, the monophosphine halide polymerizes with propylene under the action of a catalyst to obtain a high melt strength polypropylene resin with a long-chain branched structure, thereby achieving a low-cost, high-performance reactor method for preparing polypropylene resin.

This invention relates to the field of preparation method technology and discloses a method for preparing a low-density nylon foam material. The method includes selecting nylon resin as the matrix material, wherein the nylon resin is a blend of PA6 and amorphous nylon PA610 in a specific ratio, wherein the mass ratio of PA6 to PA610 is 60:40 to 80:20, and the melt strength of the nylon resin is greater than or equal to 18 Pa·s; introducing a composite foaming agent, wherein the composite foaming agent is a combination of a chemical foaming agent and a physical foaming agent; and adding a nucleating agent, wherein the nucleating agent is nano-sized silica, nano-clay, talc, or a combination thereof, wherein the mass content of nano-silica is 0.5% to 2.0%. This invention can maintain stable dimensions and mechanical properties in humid environments and has a uniform and stable cell structure.

The invention relates to the technical field of polymer composite material processing, and discloses a blending extrusion preparation method of a plant fiber reinforced biodegradable foaming material, which comprises the following steps: firstly, preparing polycaprolactone glycol, zinc isoocatanoate and absolute ethyl alcohol into a polar cosolvent system; the plant fibers are deagglomerated by utilizing the permeation effect of the solvent and a hydrogen bond damage mechanism; then, in a first extruder, a melt sealing material is formed through base resin in a specific proportion to maintain the vacuum degree of a middle-section devolatilization area, and it is ensured that absolute ethyl alcohol is completely removed; in the rear section of the extruder, zinc isoocatanoate immobilized on the surface of the fiber is utilized to catalyze the polyfunctional group epoxy chain extender to generate in-situ ring opening grafting, and a flexible transition layer is constructed on the interface of the fiber and the resin. The problems that plant fibers are prone to agglomeration and poor in resin interface bonding force are solved, the melt strength of a composite system is improved, and the prepared foaming material is uniform in foam hole and stable in performance and has good industrial application prospects.

This invention relates to the fields of polymer material synthesis technology and formulation modification technology, specifically to a narrow-distribution high-strength polyethylene and its preparation method. The invention discloses a narrow-distribution high-strength polyethylene and its preparation method, wherein the polyethylene molecular chain has long-chain branched structures grafted onto it, and the molecular weight distribution exhibits a narrow distribution characteristic. This polyethylene is prepared by a two-reactor series process, wherein the first reactor generates macromonomers containing terminal vinyl groups, and the second reactor copolymerizes the macromonomers in situ onto the polyethylene backbone, forming long-chain branched structures grafted with terminal vinyl groups. The polyethylene provided by this invention maintains a narrow molecular weight distribution while possessing excellent processing performance, combining high strength and high melt strength, and can be widely used in blown films, injection molded products, pipes, and monofilament resins, among other fields.

This invention relates to the field of polymer materials, and discloses a modified polyether ester, its preparation method and application, an elastomer additive, and an elastomer. The modified polyether ester contains structural unit A as shown in formula (I) and structural unit B as shown in formula (II), where R1 is an alkylene group having 2-10 carbon atoms, m is an integer from 5-100, n is an integer from 10-125, and R2 is hydrogen or an alkyl group having 1-5 carbon atoms; the terminal carboxyl group content of the modified polyether ester is not higher than 5 mol / t. This modified polyether ester can efficiently load elastomer additives, resulting in high activity stability of the elastomer additives, thereby improving the modification effect of the elastomer additives on the elastomer, and enabling the multiple reuse of elastomer products. Formula (I), Formula (II).

This invention relates to the field of propylene polymerization, and discloses a method for preparing polypropylene and its applications, as well as polypropylene and its applications. The method includes: S1, conducting a first polymerization reaction of propylene in the presence of a first molecular weight regulator, a first external electron donor, a functional external electron donor, and a catalyst system to obtain polymer A; S2, conducting a second polymerization reaction of propylene in the presence of a second molecular weight regulator, a second external electron donor, and polymer A to obtain polypropylene; the amount of the first molecular weight regulator is less than the amount of the second molecular weight regulator. This method introduces a functional external electron donor during the first polymerization process, while simultaneously controlling the first and second external electron donors to meet specific types and controlling the amount of molecular weight regulator at different polymerization stages, enabling the obtained polypropylene to possess both good processing properties and heat resistance.