In the process of synthesizing polyurethane resins, why must the reaction materials, containers and reactors be well dried?

Common Plastic Properties - 2007-10-20 16:35

Polysulfone (PSU, PSF) launched

Polysulfone (PSU), polysulfone vitrification Polysulfone (PSU, PSF) Temperature: 185 ℃ BR />

Polysulfone (PSU) is a class of molecules containing arylsulfone on the main chain of the amorphous non-crystalline high performance engineering thermoplastics. It is divided into transparent, opaque and filled 3 levels of specifications. As the main chain of polysulfone benzene, ether, sulfone, isopropyl "hinge" coupled together, so both the polyarylsulfone rigidity, heat resistance, and poly (aryl ether) flexibility. PSU is transparent, plastic, good dimensional stability, good deformation stability at room temperature, heat distortion temperature of 175 ° C, hydrolytic stability, excellent thermal stability, long-term use temperature of 160 ° C, short-term use temperature of 190 ° C, to maintain good performance for -100 ° C? +150°C. PSU has excellent mechanical properties, tensile strength of 70?75MPa, flexural modulus of elasticity of 2680MPa, and has excellent long-term creep resistance, mechanical properties remain unchanged in the process of long-term use. PSU also has excellent dielectric properties, and can maintain very high dielectric properties, even when it is placed in water or 190 ° C for a long time under thermal aging at 150 ° C, very small changes in its physical and electrical properties, and excellent resistance to steam properties, it is the life of the enterprise, at least 12 years of steam at 145 ° C, ? Maintains good electrical properties over a wide range of temperatures and frequencies while its fire performance to meet the more stringent safety requirements, the best variety of resistance plastics in terms of radiation. The processability of PSU can be achieved with precise tolerances, in addition to concentrated nitric acid, concentrated sulfuric acid, other acids, bases, alcohols, aliphatic hydrocarbons, and other chemical stability.

The molecular structure of PSF is shown below:

PSU Preparation: For industrial preparation, PSU is synthesized from the reaction products of the first chlorobenzene and chlorobenzenesulfonyl chloride, and chlorobenzene in an aluminum-chloride-catalyzed reduction to 4,4-dichloro-diphenyl sulfone. Next, the PSU is polymerized by the reaction of bisphenol A and sodium hydroxide in the presence of dimethyl sulfoxide in a solvent, such as by the sodium salt of bisphenol A.

Status of the application of PSU: PSU, PSU is used in a wide range of applications in the production of fields such as electrical and electronic connectors, thyristors, transformer insulating caps, insulating bushings, coils of electrical parts in contact with the backbone of the skeleton, a terminal and can be used as a collector ring and so on. In the field of printed circuit boards, sleeves, covers, parts of television systems, capacitor films, brush holders, and an alkaline battery box; the production of shields in the automotive, aerospace field, power supply components, motorized gear, battery covers, detonators, electronic ignition assemblies, lighting components, internal parts of airplanes and external parts of airplanes other than the spacecraft shields and so on. PSU production lighting, can also be used for baffles, electric actuators, sensors, etc., used in the production of the world market, the cabin members polysulfone polymer demand will continue to grow, mainly due to the combustion process of this polymer releases heat, smoke toxicity is much smaller, the gas diffusion, and fully compliant with the requirements of the safety regulations, the kitchen appliances market, the manufacture of PSU, rather than glass and stainless steel products for steam dishes, coffee containers, microwave cooking, milk and agricultural product sockets egg holders, milking machine accessories, beverage and food distributors. PSU is a non-toxic product that makes repeated contact with food utensils. PSU is a transparent new material, heat resistant to water, hydrolytically stable better than any other kind of thermoplastic, and it can be used to make coffee machines. PSU connecting tube, glass fiber or glass fiber reinforced? Reinforced polyester conundrum surface, high-strength tube outer layer, laminar flow tubes are chemical resistant, lightweight steel construction tubes, transparent and easy to monitor, commonly used in the food industry for the production of fixtures and lamps in the production of bright lights, health and medical equipment, power supplies, can be used for the production of surgical trays, aerosol dispensers, humidifiers, contact lens holders, flow controllers, equipment housings, dental instruments, liquid containers, pacemakers, respirators and laboratory equipment. Equipment. Powering the production of a variety of medical products with glass products that are less costly and less prone to breakage, it can be used in instrument housings, dental instruments, heart valve square blade cleaning systems, forming boxes of soft contact lenses, microfilters, and dialysis membranes. PSU can also be used for the insertion of artificial teeth, the adhesive strength of which is twice as high as that of acrylic; daily necessities, PSU humidifiers, hair dryers, garment steamers, camera boxes, projectors and components such as heat resistance can be used, hydrolysis products. Easily passes a 0.4?1.6MGy radiation and good dry PSU pellets at 310 ℃, mold temperature of 170 ℃ under the injection molding, suitable for laminated adhesives, all silane polysulfone, etc. PSU-SR PKXR can be used as a binder for the size of the glass fibers and graphite fibers of graphite fabric reinforced composites with silane-PSU elevator aircraft parts can be made. PSU plus solid lubricant PTFE to improve wear resistance and mechanical properties, but also used in the preparation of wear-resistant coatings, In addition, PSU is also produced for a variety of chemical processing equipment (e.g., pump housings, tower outer protective coatings, etc.). In addition, PSU also produces a variety of chemical processing equipment (e.g., pump housings, tower outer protective coatings, etc.), pollution control equipment, food processing equipment, dairy processing equipment and engineering, construction, chemical piping.

PSU development and utilization prospects: the current power supply, mainly used for electronics, electrical appliances. Electronics, electrical appliances, small size, light weight, high temperature direction of development, promote the growth of consumption of PSU. in the automotive, aerospace, medical, health, the demand for power supply units still maintains the momentum of steady growth. In 1997 the United States consumed nearly 1330 tons of sulfone resin, most of the PSU, the annual demand growth of 8% to 10%, the distribution of its consumer electronics, electricity accounted for 35%, 25%, food, daily necessities, automotive, aerospace, etc. accounted for 15%, accounted for 12% of the medical industry accounted for 4%, and 9% of the other, in 1997 the Western European PSU consumption of 25 million tons of 46% for electronics, electrical, automotive, aerospace accounted for 28%, and the other 9%, in 1997, Western Europe PSU consumption of 25 tons. Automotive, aerospace accounted for 28% of its use in the distribution, medical equipment accounted for 10%, industrial accounted for 10%, other accounted for 6%. Western Europe PSU annual consumption growth rate of 14?% to 17%, to 2000 demand up to nearly 4,000 tons, Japan in 1997 PSU consumption of 950 tons, an average annual growth rate of 7% to 8%, to 2000, demand will reach about 12 million tons. Within the field of optical applications, Japan, lens production, PSU has been replaced, these optical sensors can be used by PMMA and PC within the automatic controller, the market size has been formed. In addition, in the application of the fuse box, also consumes PSU resin hundred tons. PSU production capacity of less than 700 tons / year production of about 400 tons / year, manufacturers are mainly Shanghai Shuguang Chemical Plant (300 tons / year), and Dalian, in the first plastic plant (200 tons / year) and Jilin University Journal (2 million tons / year), etc., the pilot production scale, the output can not meet the needs of the domestic market, the need to rely on imports to make up for the quality of the product, in addition to the foreign large Gap compared. Domestic applications in the field of food, health, medical and other development work, only in the initial stage, after the alloy products need to be further developed. Therefore, the development of polysulfone products will be promising, promising development and utilization.

Polysulfone (PSF),

Polysulfone chain molecules contain thermoplastic resins on the main chain, the English name of Polysalfone (referred to as PSF or PSU) common bisphenol A-PSF (usually called PSF), polyarylsulfone, polyethersulfone two.

PSF slightly amber amorphous state of transparent or semi-transparent polymer, is with excellent mechanical properties, rigidity, abrasion resistance, high strength, even at high temperatures to maintain excellent mechanical properties is its outstanding advantage, its range of 150 ° C, the long-term use of the temperature of 160-100 ° C, the short-term use of the temperature of 190 ° C under the high thermal stability and hydrolysis resistance. Good dimensional stability, low molding shrinkage, non-toxic, resistant to radiation, fire, extinguishing. Excellent electrical properties over a wide temperature and frequency range. Good chemical stability, in addition to concentrated nitric acid, concentrated sulfuric acid, halogenated hydrocarbons, general acids, alkalis, salts, ability to swell in ketones, esters. Poor UV and weather resistance. Poor fatigue strength is a major drawback.

PSF is pre-dried to a moisture content of less than 0.05% before molding. PSF can be injection molding, extrusion molding, thermoforming, blow molding, high melt viscosity, viscosity control is a critical treatment, heat treatment should be carried out after treatment to eliminate internal stress.

PSF can be precisely sized products. Mainly used in electrical and electronic products, food, daily necessities, automotive, aerospace, medical and general industrial sectors, in the production of contactors, connectors, transformer insulation, SCR cap insulation bushings, coil bobbins, terminals, printed circuit boards, bushings, hoods, TV system parts, capacitor film, brush holders, alkaline batteries, wires and cables coating.

PSF can also be made into shielding components, electronic gears, battery covers, external spare parts for aircraft, spacecraft external shields, photographic equipment baffles, lamp fittings, sensors. Substitute glass and stainless steel steam racks, microwave cooking coffee containers, milk containers, milking machine accessories, beverage and food distributors. Health and medical equipment, surgical trays, nebulizers, humidifiers, dental instruments, flow controllers, water tanks and laboratory equipment, but also for dentures, high bond strength, but also do chemical equipment (pump housings, tower outer protective layer acid nozzles, pipes, valves, containers), food processing equipment, dairy processing equipment, environmental protection and infection control equipment.

Aromatic sulfone (PASF), and polyethersulfone (PES) better heat resistance, excellent mechanical properties, maintained at high temperatures

Polysulfone - Plastic Star of the New Century [2003-2-27]

Polysulfone (PSF), with excellent physical and mechanical good high-temperature creep, resistance to hydrolysis, non-toxic, electrical insulating properties and thermal properties, and resistance to ultraviolet radiation. UV radiation, its products are light weight, low cost, not only can replace the various plastics, can also be replaced with metal, can be injection molding, extrusion processing, molding and other general methods, has gained a wide range of applications in the field of electronics, machinery, instrumentation, medical equipment, aerospace, automotive, as well as to maintain a steady growth momentum.

Electrical and electronic fields: electrical and electronic PSF consumption of large countries, electronic appliances, small size, light weight, high temperature direction of development, promote the growth of PSF consumption. PSF can be used to make a variety of contacts, contact components, SCR caps, insulating sleeves, coil skeletons, terminals and electric rings and other electrical components, printed circuit boards, sleeve covers, and TV system parts capacitors, transformer insulation film, brush holders, alkaline battery boxes.

AUTOMOTIVE, AEROSPACE FIELD: In the aerospace field and automotive manufacturing, PSF parts are suitable for the production of shields, motorized gears, battery covers, detonators, electronic ignition assemblies, lighting components, aircraft interior fittings and parts for the exterior of aircraft, and spacecraft exterior shielding. In addition, PSF lighting shades, motorized transmissions, and sensors can be. In the world, polysulfone polymers used to make the cabin parts of the demand is growing, mainly due to the combustion process of such polymers emit less heat, less smoke generated, less toxic gas diffusion, in full compliance with the requirements of safe use.

Cookware, Food Processing Machinery: PSF is recognized as a non-toxic product certified by the U.S. FDA and can be made into repeated contact with food utensils. PSF as a transparent new material, hot water, hydrolytic stability is superior to other thermoplastics, instead of glass and stainless steel products to achieve the required performance standards.

Kitchenware markets PSF to steam racks, coffee containers for microwave cooking, milk and produce containers, egg holders, milking machine accessories, and beverage and food distributors. In food packaging, PSF can be used in a variety of containers inside containers that function well through microwaves to make microwaveable appliances. In addition, PSF can also be used as a connecting tube, the outer layer of pipes, the inner layer of high-strength, chemical-resistant, steel tubing, light, transparent, to facilitate clinical control, usually in the food industry, and in the use of bright lights in the production of lampshades.

In health, medical, and PSF fully comply with hygiene requirements, can withstand 130 ℃ steam, rather than repeated sterilization of stainless steel, aluminum, etc. to reduce the cost of medical equipment for the health. PSF produces medical devices: surgical trays, nebulizers, humidifiers, contact lens fixtures, flow controllers, instrument covers, dental instruments, pacemakers, respirators, etc.. PSF produces medical device products, glass products that are less costly and less prone to breakage, making instrument housings, dental instruments, heart valve cartridges, blade cleaning systems, forming soft contact lens cases, microfilters, dialysis membranes. It can also be used to insert artificial teeth, whose strength is twice as high as that of polyacrylate.

Commodity applications: PSF is produced for household products, mainly for thermal hydrolysis products, humidifiers, steam irons, camera cases, projector components.

Adhesives, coatings: All polysulfones with silane can be used as adhesives. For sizing glass fiber and graphite fiber composites. PSF will be able to produce silane graphite fabric reinforced elevator and aircraft parts. PSF and solid lubricants are PTFE and abrasion resistant coatings can be made.

Industrial applications PSF can also be manufactured in a variety of chemical processing equipment, pump casing, tower outer protective layer, food processing equipment, pollution control equipment, dairy processing equipment, engineering, construction, chemical piping and so on.

The U.S. demand for PSF is growing 8% to 10% annually, from 14% to 17% annual demand growth in Western Europe for PSF, Japan's PSF annual demand growth of 7% to 8% PSF. Polysulfone in the international market is in short supply, the U.S., Western Europe, Japan need to be imported. Domestic, food, health, medical and other fields within the application program development is still in the initial stage, from the development trend, the demand will continue to grow steadily PSF.

Introduction of polysulfone resins

Polysulfone resins, after the mid-1960s, the emergence of a class of engineering thermoplastics, is a class of the main chain contains sulfone village with the nucleus of the amorphous thermoplastic aromatics. According to their chemical structure, can be divided into polysulfone, aliphatic and aromatic polysulfone. Aliphatic polysulfone is not alkali resistant, no heat, no practical value, while the aromatic polysulfone bisphenol A sulfone and its modified products - non-bisphenol A polyarylsulfone, polyethersulfone, the more widely used have been commercially produced high molecular weight polysulfone resins. Bisphenol A polysulfone resin was successfully developed in 1965 under the trade name UDEL polysuifone of Union Carbide Corporation (UCC), polyarylsulfone was successfully developed by the U.S. 3M Company in 1967 under the trade name Astrel;: polyethersulfone of the United Kingdom Bunemun (ICI), was developed in 1972 under the trade name Victrex Corporation. Polysulfone resin structure of the oxygen of the high resonance of the diaryl sulfone group, the sulfur atom of the fully oxidized state, and high resonance of the sulfone group of polysulfone resins have excellent resistance to oxidation and heat, with excellent melt stability, these are high temperature molding and extrusion molding process must have the performance of the process.

Polysulfone

Polysulfone (PSF) is a transparent, high temperature resistant, stable, high performance engineering thermoplastic. Amorphous, it has low flammability, fumes, and maintains good dielectric properties near the glass transition temperature of 374°F. These properties are largely dependent on the properties of the molecules in its structure. These properties depend primarily on the diarylsulfone groups consisting of polysulfone in the molecular structure. The electron-withdrawing groups from the benzene ring of these groups. The sulfone group is an antioxidant for the **** vibration of the para-oxygen atom and agricultural products. The high resonance, so that the key has been enhanced so that the group forms a planar structure. As a result, the polymer has good thermal stability and rigidity at elevated temperatures. The ether bonds, such that the molecular chain has the flexural resistance and hence, good impact strength. Due to the hydrolytic stability of the bond connecting the benzene ring, so it is not easy to hydrolyze, acid, alkali solutions of polyethylene machine.

Sulfone (PSF) can be handled by general thermoplastic processing equipment, but under high-temperature conditions is required. In injection molding, extrusion molding, thermoforming, and must be dried.

Polysulfone (PSF) behaves as follows:

Polysulfone is resistant to acids, alkalis, salt solutions, detergents, petroleum, and alcohols, even at high pressures and high temperatures on the line. It does not tolerate the phenomenon of polar solvents such as ketones, halogenated hydrocarbons and aromatic hydrocarbons.

Polysulfone is used continuously with 300°F steam. Water at 180°F has a maximum pressure of 13.8 MPa (static load) and 17.2 MPa (intermittent load). To maintain long-term transparency and impact resistance constants, the maximum pressure in water, at 180°F, is 3.5 MPa (static load) 6.9 MPa (intermittent load). The temperature of the water is lower, and its pressure is higher: at 72°F, for example, the maximum pressure is 20.7MPa (static load), 24.7MPa (intermittent load). At 20.7 MPa, the creep (strain) of polysulfone is only 1% after 10,000 hours at room temperature. At a pressure of 210°F, 2.07 MPa, the total strain was still less than 2% after 1 year. After prolonged use at 300°F, polysulfone's strength and modulus increased by 10%, maintaining 90% of the dielectric strength, and the impact strength remained at 70%. Polysulfone has a tensile impact strength of 200 ft. lb/in2. Months of exposure to high temperatures, such as 300°F will produce an annealing effect at the beginning of the exposure that can reduce its property values by 30%. However, these properties remain constant over the two-year test period.

American Underwriters Laboratories Association polysulfone 320°F continuous use. Because its glass transition temperature (Tg) is 374°F, it is in intermittent use can withstand higher temperatures. Amoco Udel polysulfone card has been approved by the U.S. Food and Drug Administration (FDA) and is used in the food industry, and in one or more applications.

Polysulfone has good electrical properties: the dielectric constant and dielectric loss factor are very low, but still has high dielectric strength and volume resistivity. And it can be constant over a wide range of temperatures and frequencies (or microwave frequencies).

Polysulfone chemically coated with nickel and copper has an adhesive strength of 20 lb/in.

Grade Polysulfone Polysulfone is available in injection-molded grades, extruded grades transparent and opaque products. There are also special medical grades that meet the requirements of the United States Pharmacopeia XIX Class VI.

Applications for Polysulfone

Polysulfone is used in a wide range of applications for medical device parts that require sterilization.

Polysulfone food processing equipment including: steam cooking pots, coffee filters, homemade coffee makers, milking machines and tools, tongs, scraper blades and tubing.

Polysulfone replaces metal in piping applications, including valve assemblies and fittings. It has the advantage of being resistant to chlorine, corrosion, and more.

Polysulfone can be used in a number of semi-permeable membranes such as kidney dialysis. Reverse osmosis and ultrafiltration.

Electronic, electrical applications, including connectors, fuses. Battery boxes, switches, capacitor membranes, and circuit boards.

Chemical processing equipment, such as pump applications. Filter plates, tower packing, and corrosion resistant piping. Various Methods

Polysulfone Processing Behavior

Polysulfone can be injection, extrusion, blow molding, and rotational molding. The general level of melt flow grade is suitable for injection, extrusion molding; molecular weight models can be used for blow molding, extrusion molding. The amber transparent resin itself can be colored. Along with glass fibers, inorganic fillers, carbon fibers and fluoroplastic composites.

Polysulfone in the molding process shear rate is not sensitive, high viscosity, low melt flow molecular orientation, easy to obtain uniform products, easy to adjust the size and shape of the product suitable for extrusion molding shape.

1. Polycarbonate fluidity: When the shear rate is low, the melt viscosity of LDPE and polystyrene is higher than that of polysulfone and polycarbonate. However, as the shear rate increases, because of the lower degree of orientation, the melt kernel degree of LDPE and PS decreases sharply, and the flow direction of PC and PSF does not change much. The viscosity is low at high temperatures. The temperature of the screw barrel with Chess can be adjusted to control its fluidity during the molding process. The slope of the PSF viscosity-temperature curve coincides with that of PC, therefore, using the same molding and PC equipment, injection molding machine and die extruder, one can obtain the preferred PSF product in the following way.

2. Dry raw materials: Polyester staple fiber raw materials must be sufficiently dry before molding, or the phenomenon of bubbles appearing on the surface of the silver product. Total inventory of raw materials moisture content of about 0.3%, less than 0.05% of the drying operation. The lower corner of the material is crushed, using renewable dry.

3. molding

4. mold: the design of the mold should pay attention to the minimum resistance to the flow of the melt, high temperature and high pressure injection molding when the shortest path of material flow. The diameter of the injection nozzle should be greater than 3mm, when the product size reaches 100mm, the diameter of the injection nozzle should be greater than 4mm.