1110results about How to "Improve melt strength" patented technology

Polyester compositions that provide a higher throughput in calendering processes may be prepared from a polyester having crystallization half time of at least 5 minutes, an inherent viscosity of about 0.55 to about 0.75 dL/g, a branching monomer, and a release additive. The polyester compositions show a combination of excellent melt strength with good shear response that permits higher calendering line speeds before melt fracture occurs. Also disclosed are processes for film or sheet by calendering the above compositions and the film or sheet produced therefrom. The polyester compositions, film, or sheet also may include plasticizers and/or flame retardants to increase their flexibility and enable their use in commercial applications requiring flame resistance. The film and sheet have excellent appearance and can be used in a wide range of decorative and packaging applications.

A thermoplastic olefin (TPO) composition comprises (1) a major amount by weight of (a) a substantially linear homopolymer or copolymer of a C₂-C₁₀ α-olefin in major proportion to (b) a long chain branched a linear homopolymer or copolymer of a C₂-C₁₀ α-olefin, (2) a minor amount by weight of a cross linkable elastomer, and (3) at least one thermally decomposing free radical generating agent present in an amount sufficient to promote an increase in melt strength of the composition over that of the melt strength of the linear homopolymer or copolymer of a C₂-C₁₀ α-olefin alone and insufficient to substantially degrade the α-olefinic polymers. The TPO composition is prepared by melt blending the components at a temperature sufficient to melt said homopolymers or copolymers of a C₂-C₁₀ α-olefin and thermally decompose said agent. Articles are thermoformed from the thermoplastic olefin.

The present invention is directed to an oriented, foamed article having an integral security element, and a method of making the article. The oriented foam article is particularly useful in the preparation of printed security documents such as currency, stock and bond certificates, birth and death certificates, land titles abstracts and the like.

The invention discloses a preparation method of polypropylene with high melt strength. The method includes i) a step of, under the action of a Ziegler-Natta catalyst containing a silane type external electron donor, subjecting propylene or propylene with other alpha-olefin to polymerization to obtain a polymer A having a melt mass flow rate of 0.01-0.4 g/min, with a hydrogen concentration being not more than 400 ppmV; ii) a step of adding a 1,3-diether type external electron donor and premixing the 1,3-diether type external electron donor and the polymer A; iii) a step of, under the existence of hydrogen and the premixed materials in the step ii), subjecting the propylene or the propylene with other alpha-olefin to polymerization to obtain a polymer B having a melt mass flow rate of 1.0-60 g/10min; and a step of preparing polypropylene C with high melt strength comprising the polymer A and the polymer B. The melt mass flow rate of the polypropylene C is 0.8-15 g/10min. The preparation method is simple and feasible and is convenient to operate and prone to industrial production. High-performance products with high melt strength and wide molecular weight distribution can be prepared by the method. The method has wide application prospect.

Branched crystalline polypropylene compositions and methods for the preparation of branched crystalline polypropylene compositions are provided. For example, described herein is a process of preparing a branched crystalline polypropylene composition that includes combining two or more different metallocene catalyst compounds with a polymerization medium that includes propylene, for a time sufficient to provide branched crystalline polypropylene that has from 0.0 wt % to 2.0 wt % ethylene and a heat of fusion of 70 J/g or more.

The invention relates to a high melt strength polypropylene material and a preparation method. The high melt strength polypropylene material consists of 100 parts of polypropylene, 5-60 parts of high-melting point crystalline polymer, 2-50 parts of compatilizer, 0-40 parts of polyethylene and other additives according to parts by weight. The preparation method includes the following steps of: measuring the polypropylene, the high-melting point crystalline polymer, the compatilizer, the polyethylene and a processing agent according to formula amount, premixing the materials uniformly and then melting and blending the materials by a screw extruder at controlled temperature and rotating speed, thus obtaining the high melt strength polypropylene material which is applicable to extrusion foaming and other hot forming technologies.

The invention discloses an environment-friendly single-layer microcellular foamPVC (polyvinyl chloride) wood-plastic composite board and a preparation method thereof. According to an adopted raw material formula,the board comprises the components in percentage by mass as follows: 20%-60% of a PVC reclaimed material, 15%-45% of PVC resin, 5.6%-10% of wood fiber powder, 5%-8.9% of filler, 4%-4.4% of a foaming conditioning agent, 1%-1.5% of a compound stabilizer, 0.7%-0.9% of a foaming agent, 2%-2.5% of a reinforcing agent, 2.2%-2.4% of an impact modifier, 0.3%-0.45% of a lubricating agent, 0.1%-0.15% of a coupling agent and 3%-5% of a functional additive, and the functional additive is an anti-aging agent, a fire retardant or a coloring agent. The composite board has the processability similar to that of wood, can substitute for a wood board and also has thecharacteristics of fireproof property, moistureproof property, smooth and attractive appearance and the like, and the wood does not have the characteristics; according to the preparation method of the composite board, waste PVC can be used for performing cycle production, waste materials can be changed into things of value, waste of wood resources can be reduced, and the pollution caused by plastic products to the environment can also be avoided.

The invention discloses a high-melt strength polypropylene foam material and a preparation method thereof. The matrix resin of the foam material is high-melt strength polypropylene. The high-melt strength polypropylene foam material has the following characteristics: (1) the melt index (190 DEGC/2.16kg) is 1.0-10g/min; (2) the molecular weight distribution Mw/Mn is 6-20; (3) the content of the molecules with molecular weight over 5 million is greater than or equal to 0.8% by weight; and (4) (Mz+1)/Mn is greater than or equal to 70. The foam material is prepared by premix melting, blending and foaming of the following components in parts by weight: 100 parts of high-melt strength polypropylene and 1-15 parts of foaming agent. The obtained foam material meets the environmental protection requirements of degradability, uniform cell, high physical heat resistance, low production cost and smooth surface, and is suitable for continuous large-scale production.

This invention refers to a kind of preparation method of PC/ABS alloy, adopts ABS/PP-g-MAH as the compatiblizing agent of PC/ABS and is composed of polycarbonate, acrylonitrile-styrene- butadiene copolymer (ABS), ABS/PP grafts, antioxidant, lubricant and other auxiliary agents. We mix them in double-screwed extruder, discharges, extrudes, cools, dries, granulates and gets the turnoff. The invention is characterized with good mechanical properties, processing propertyies and high thermal endurance and is adaptable to injection molding.

The invention discloses a low-melting point and transparent PET (polyethylene terephthalate) copolyester, its preparation method and application. The PET copolyester comprises, by mass: 60-84% of PET, 10%-30% of a unit derived from isophthalic acid, 5%-29% of a crystallization adjusting agent, and 0.03-2% of a branching agent. According to the preparation method, in a synthesis process of PET, based on p-phthalic acid (PTA) and ethylene glycol (EG), the unit derived from isophthalic acid, the crystallization adjusting agent and the branching agent are added to undergo a chemical reaction together, thus obtaining the low-melting point and transparent PET copolyester. The PET copolyester provided by the invention has an intrinsic viscosity greater than 0.9dL/g and a melting point lower than 230DEG C, can be solidified into an amorphous state from a molten state during injection molding, and has good transparency as well as further improved processing performance.

The invention provides a preparation method of a maleic anhydride drafted polypropylene resin graft polymer, relating to a maleic anhydride melt-drafted polypropylene resin technology. The polypropylene resin is an antioxidant-free polypropylene powder. The preparation method comprises the following steps of: melting and blending 0.1 to 1 part of antioxidant and the polypropylene powder in 100 parts by weight of the polypropylene, and then carrying out the melting free radical grafting reaction on the polypropylene resin melted and blended with the antioxidant; initiating the melting free radical grating reaction by a peroxide initiator, and introducing an auxiliary monomer except for adding grafting monomer maleic anhydride, wherein the auxiliary monomer is an organic monomer containing two or more carbon-carbon double bonds, the using amount of the auxiliary monomer is 2 to 8 parts in 100 parts by weight of the polypropylene resin, and the using amount of the maleic anhydride is 1 to 8 parts in 100 parts by weight of the polypropylene resin. The preparation method of the maleic anhydride drafted polypropylene resin can obtain the polypropylene resin graft polymer with higher molecular weight and melt strength.

The invention discloses a method for preparing polypropylene with high melt strength, which comprises melt-blending polypropylene, monomer containing double bond, peroxide, dithiocarbamate series substance and antioxidant. The dithiocarbamate is added as adjuvant to inhibit the propylene degradation of the peroxide, improve the graft ratio, reduce monomer amount containing double bond, and save the cost. The obtained polypropylene with high melt strength has melt strength more than 2-15 times of that of raw material, and gel content smaller than 10%.

The invention provides a polylactic acid composition and a polylactic acid product. The polylactic acid composition comprises the following components by weight percent: 50 to 80 percent of polylactic acid, 0 to 35 percent of adipic acid-polybutylene terephthalate, 0 to 35 percent of poly(butylene succinate), 0.05 to 0.5 percent of peroxide, 0.05 to 0.5 percent of chain extendor and 3 to 15 percent of plasticizer, wherein the content of the adipic acid-polybutylene terephthalate and the content of the poly(butylene succinate) are not 0 percent. The mechanical properties such as melt strength, elongation at break, tenacity and anti-tear strength of the polylactic acid composition provided by the invention are improved, so that the polylactic acid composition with better comprehensive mechanical properties can be obtained, and the polylactic acid composition has more stable processability and better film forming stability.

The invention discloses a biodegradable polylactic acid composite material, and a preparation method and an application thereof. The biodegradable polylactic acid composite material comprises the components of, by weight, 100 parts of high-molecular-weight polylactic acid, 10-40 parts of low-molecular-weight polylactic acid, 10-30 parts of biodegradable copolyester, 0.1-3 parts of a chain extender, 0.1-3 parts of an anti-hydrolysis agent, 0.1-5 parts of a nucleating agent, 5-20 parts of an inorganic filler, and 0.1-0.8 parts of an antioxidant. The weight average molecular weight Mw of the high-molecular-weight polylactic acid is greater than 100000 and no greater than 200000, and the weight average molecular weight Mw of the low-molecular-weight polylactic acid is no lower than 60000 and no greater than 100000. The polylactic acid composite material provided by the invention has high melt strength, high toughness, high heat resistance, high water resistance and good processing properties. The material can be widely applied in the fields such as toys, offices, cars and electronic appliances.

The invention relates to special resin with high melt strength for foaming of polylactic acid and a preparation method thereof, and belongs to the technical field of macromolecules. The special resin is prepared from the following raw materials in parts by weight: 60 to 95 parts of polylactic acid, 1 to 20 parts of biodegradable copolymer, 0.1 to 1 part of chain expander, 1 to 5 parts of melt enhancer, 0.1 to 5 parts of nucleating agent, and 0.5 to 2 parts of lubricant. The special resin has the advantages and beneficial effects that by improving the melt strength of the polylactic acid and enhancing the adsorbing ability of polylactic acid on CO2 (carbon dioxide), the foaming property of the polylactic acid is enhanced. The used devices are universal devices in the technical field of macromolecules, such as a double-screw extruder, a crystallizing drier and a plastic extrusion foaming machine. The special resin has the advantages that the operation is simple and convenient, the control is easy, the industrialized implementing is easy, and the economic benefit is high.

The invention discloses a high-toughness and highly heat-resistant polylactic acid (PLA) alloy material and a preparation method thereof. The material comprises the following components in part by weight: 10 to 80 parts of PLA, 10 to 80 parts of heat-resistant artificial macromolecules, 5 to 15 parts of toughening agent, 0.4 to 1 part of hydrolysis inhibitor, 0.1 to 1 part of anti-aging agent and 0.1 to 1 part of antioxidant. Compared with the prior art, the material has the advantages that: the toughness and heat resistance of a PLA composite material are improved simultaneously; blending modification which is an important way of polymer modification is simple and practicable and low in cost; and by a blending system, the performance of the components can be comprehensively balanced, the components are complemented, and the performance weakness of each single component is avoided, so that a polymer material with ideal comprehensive performance is obtained.