Phenolic resin, originally colorless or tawny transparent, is often addedColorantIt is red, yellow, black, green, brown, blue and other colors, and it is granular or powdery.It is resistant to weak acid and weak base, decomposes when encountering strong acid, and corrodes when encountering strong base.Insoluble in water, soluble inacetone, alcohol, etcOrganic solventMedium.It is obtained by polycondensation of phenol formaldehyde or its derivatives.[1]
The phenolic resin industry will experience the test of "cold winter" after entering December. Many enterprise managers and sales personnel still have great hopes for the orders at the end of the year.However, the collection control is more strict.As a result of competition in the industry, there are generally more than two prices quoted in the phenolic resin industry, one is the standard price and the other is the cash transaction price.Many enterprises make further concessions to cash customers in order to quickly withdraw funds, especially at the end of the year to stimulate sales. Similar situations emerge in endlessly.Like the refractory industry, phenolic resin is faced with the situation that some small enterprises reduce prices to achieve the purpose of signing orders.This situation has little impact on those small-scale production workshops. Their production costs are low, and they can also cope with the price reduction.However, for large enterprises such as Pingyang Industrial Co., Ltd., the raw materials and processing, technology and scale are very large, and all costs are relatively high. If prices continue to decline, they will lose money.Therefore, in the face of these low-cost competitors and bleak market, there is no alternative.However, if enterprises want to survive, their capital will have to be turned back. Under these pressures, many large enterprises have no choice but to reduce the price of phenolic resin, so as to solve the problem of inventory backlog more quickly.[5]
Future development
Research
The production and use of phenolic resin will bring a certain degree of pollution to the environment and affect the entire ecological environment. However, attention should be paid to or strengthen the treatment of pollution, including wastewater treatment, waste phenolic resin products andcompound materialThe recycling of phenolic resin can make it develop healthily and rapidly.
Latest development
The development and research of phenolic resin mainly focus on the aspects of reinforcement, flame retardancy, low smoke and molding applicability, and develop towards functionalization and refinement. Scientists in various countries focus on the research and development of phenolic resin materials with high added value.
New environmentally friendly resin
The new phenolic resin isPolymer compound, is produced by condensation reaction of phenol and aryl alkyl ether.New phenolic resin has good mechanical properties and heat resistance, and is widely used in diamond products, grinding wheel manufacturing and other industries. New phenolic resin has strong adhesion,chemical stabilityGood, high heat resistance, small shrinkage when hardening, and stable product size.The adhesive strength is more than 20% higher than that of phenolic resin, and the heat resistance is more than 100 ℃ higher.The new phenolic resin products can be used for a long time at 250 ℃, and the products are resistant to moisture and alkali.
The new phenolic resin can be used as the bond of diamond grinding wheel. The application method is: the new phenolic resin and phenolic resin are mixed in 1:3, which not only improves the strength of phenolic resin, but also improves the heat resistance and grinding ratio.For example, if the new phenolic resin is used alone, the service life of the grinding wheel is 8 times that of the phenolic resin, the strength of the grinding wheel is about 30% higher than that of the phenolic resin products in the production process, and the grinding effect is also improved.[5]
time
Development history
1872
German chemistBayer (A. Baeyer) first found that phenols and aldehydes can be condensed to obtain amorphous brownish red untreated dendritic products in the presence of acid, but no research was carried out.
1902
Blumer(L. Blumer) used 135 parts of tartaric acid as catalyst to obtain the first commercial phenolic resin, named Laccain, but did not form an industrial scale.
1905-1907
Founder of phenolic resin American scientistBuckland(Baekeland) has carried out systematic and extensive research on phenolic resin. In 1909, he put forward a patent on the "pressure and heating" curing of phenolic resin, realizing the practicality of phenolic resin. Someone proposed that this year should be the first year of phenolic resin (or the first year of synthetic polymer).
1907
Buckland applied for a patent on the "pressure heating" curing of phenolic resin.On October 10, 1910, Bakelite Company was founded, which was distributed in many countries [affiliated to United Carbon (UC) Company in 1939]. They applied for more than 400 patents successively, foresaw the main applications other than phenolic resin as ablation material, and solved the key problems in the application of phenolic resin.Buckland also successfully obtained the technology of applying high pressure to cure the phenolic prepolymer. He clearly pointed out that whether the phenolic resin has thermoplasticity depends on the dosage ratio of phenol to formaldehyde and the type of catalyst used. In the presence of alkaline catalyst, even if the phenol is excessive, the product is also a thermosetting resin, which can be transformed into insoluble and insoluble resin after being heated.
1911
AylesworthHexamethylenetetramineIt can solidify the phenolic resin and change it into an insoluble and fusible state, making it have high electrical insulation and other application characteristics.Therefore, phenolic resin began to be used in electrical insulation products.
1912-1913
RussiascientistPetrov、TarasovThey studied the reaction of phenol and aldehyde in the presence of petroleum sulfonic acid and aromatic sulfonic acid, and invented a method for preparing phenolic resin injection products by injection molding.
1913
German scientistsAlbertInvented rosinModified phenolic resinThe invention paves the way for the successful application of phenolic resin in the paint field.
1914
Japan introduced Buckland technology inTokyoIt started to produce phenolic resin, creating a precedent in Asia.
1923
Phenol furfural molding powder was put into production in the United States.
1930
Phenolic foam was put into production in the United States.
1937
A plasticized etherified phenolic resin was developed and used in paint coatings.
1945
High ortho phenolic resin and its rapid prototyping molding powder were industrialized in the United States.
1946
NBR modified phenolic resin and its molding powder were put into production in the United States.
1949
Aniline modified phenolic molding powder was commercially available.[5]
Physical and chemical properties
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Structural Diagram of Linear Phenolic Resin
The solid phenolic resin is a yellow, transparent, amorphous block material, which is reddish due to the presence of free phenol. The average specific gravity of the solid is about 1.7,SolubleAlcohol, insoluble in water, water, weak acid, weak basesolutionstable.Composed of phenol andformaldehydePolycondensation under catalyst conditionneutralizationResin made by washing.Due to different catalysts, they can be divided into thermosetting and thermoplastic.Phenolic resin has good acid resistance, mechanical properties and heat resistance, and is widely used in anti-corrosion engineeringan adhesive, flame retardant materials, grinding wheel manufacturing and other industries.[1]
Phenolic resin refractory
Liquid phenolic resin is yellow and dark brown liquid. For example, alkaline phenolic resin is mainly used as casting binder.
High temperature performance
The most important feature of phenolic resin is its resistance tohigh temperatureIts structural integrity and dimensional stability can be maintained even at very high temperatures.It is for this reason that phenolic resin is used in some high-temperature fields, such as refractories and friction materials,binderAnd casting industry.
Bond strength
One important application of phenolic resin is as binder.Phenolic resin is a multifunctional resin with various organic and inorganicfillerAll compatible substances.Properly designed phenolic resin has a very fast wetting speed.And can beAbrasive tool, refractory materials, friction materials and bakelite powdermechanical strength, heat resistance and electrical properties.
Water soluble phenolic resin orAlcohol solubilityPhenolic resin is used to impregnate paper, cotton clothGlass、asbestosAnd other similar substances provide them with mechanical strength, electrical properties, etc.Typical examples include electrical insulation and mechanical lamination manufacturing, clutch discs andAuto filterUse filter paper.
High carbon residue rate
Under the condition of inert gas with a temperature of about 1000 ℃, the phenolic resin will produce very high carbon residue, which is conducive to maintaining the structural stability of the phenolic resin.This characteristic of phenolic resin is also an important reason why it can be used in the field of refractory materials.
Low smoke and low toxicity
Compared with other resin systems, phenolic resin system has the advantage of low smoke and low toxicity.In case of combustion, the phenolic resin system produced with scientific formula will slowly decompose to generate hydrogen, hydrocarbons, water vapor and carbon oxides.The decomposition process produces relatively little smoke and has relatively low toxicity.These characteristics make phenolic resin suitable for public transportation and fields with very strict safety requirements, such as mines, fences and construction industries.
Chemical resistance
The cross-linked phenolic resin can resist the decomposition of any chemical substance.for examplegasoline, oil,alcohol，glycol, grease and various hydrocarbons.Due to its chemical resistance, it is suitable for making kitchen and toilet appliancesDrinking water purification equipment(phenolic carbon fiber)Bakelite tea trayTea sets are widely used in cans, cans (national standard GB 05009.069-2003), liquid containers and other food and beverage packaging materials.
heat treatment
Heat treatment will improve theGlass transition temperature, which can further improve the properties of the resin.Glass transition temperature and crystalline solids such aspolypropyleneThe melting state of is similar.The initial glass transition temperature of phenolic resin is related to the curing temperature used in the initial curing stage.The heat treatment process can improve themobilityIt can promote the reaction to take place further, at the same time, it can also remove the residual volatile phenol, reduce shrinkage, enhance dimensional stabilityhardnessAnd high temperature strength.At the same time, the resin tends to shrink and become brittle.Resin post-treatment temperature risecurveIt will depend on the initial curing conditions of the resin and the resin system.
Foaming property
Phenolic foam is a kind of foam plastic made from phenolic resin by foaming.Compared with polystyrene foam, PVC foam, polyurethane foam and other materials that dominated the market in the early days, it has special excellent performance in flame retardancy.With light weight, large rigidity, good dimensional stability, chemical corrosion resistance, good heat resistance, flame retardant, self extinguishing, low smoke, flame penetration resistance, no spillage in case of fire, and low price, it is an ideal insulation and heat insulation material for electrical appliances, instruments, buildings, petrochemical industry and other industries, and has received widespread attention.
Phenolic foam has become one of the fastest growing varieties of foam plastics.Consumption continues to grow, the scope of application continues to expand, and research and development at home and abroad are quite active.However, the biggest weakness of phenolic foam is its brittleness and high porosity, so improving its toughness is the key technology to improve the performance of phenolic foam.[2]
Preparation method
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Principle of synthesis
Reaction type
Principle of synthesis
Reaction equation
Addition reaction
Under appropriate conditions, monohydroxymethylphenol can continue to undergo addition reaction to generate binary and polyhydroxymethylphenol:
Addition reaction
Condensation and polycondensation reaction
Condensation and polycondensation reactions can occur between hydroxymethylphenol and phenol molecules, or between various hydroxymethylphenol molecules, depending on the reaction conditions.include:
Condensation and polycondensation reaction
The continuous condensation reaction results in the formation of phenolic resin with a certain molecular weight. Due to the gradual characteristics of the condensation reaction, the intermediate products are quite stable and can be separated for research.
After years of research and analysis, it is generally believed that the main factors affecting the synthesis, structure and characteristics of phenolic resin are as follows:
(1) Chemical structure of raw materials;
(2) Molar ratio of phenol to aldehyde;
(3) Acidity and alkalinity of reaction medium;
(4) Production operation method.
How to understand addition polymerization and polycondensation
Molecular diagram of polymerization and polycondensation
Addition polymerization and polycondensation are two basic reactions for the synthesis of organic polymers.Although these two reactions are both reactions in which monomer (small molecule) generates polymer (large molecule), they still have essential differences.
Addition polymerization is the abbreviation of addition polymerization, which refers to the polymerization of unsaturated hydrocarbons or substances containing unsaturated bonds into polymers through the addition of unsaturated bonds.For example, ethylene addition polymerizationpolyethyleneUnder the conditions of appropriate temperature, pressure and the presence of catalyst, the double bond in ethylene molecule will break one of the bonds, and an addition reaction will occur, so that the carbon atoms in ethylene molecule will combine into a very long bond.
The reaction product is polyethylene, which is a compound with high relative molecular weight, and its molecular composition can be expressed as (CtwoHfour)n。
Addition polymerization can be divided into homopolymerization and copolymerization according to the type of monomers participating in the reaction.The addition polymerization by only one monomer is called homopolymerization, and the reaction to synthesize polyethylene is homopolymerization.The polymerization reaction in which two or more monomers participate together is called copolymerization.For example, synthesisbutadiene styrene rubberThe reaction of is copolymerization.
The characteristics of addition polymerization are:
(1) The monomer must be a compound containing unsaturated bonds such as double bonds.For example, materials containing unsaturated bonds such as vinyl chloride and acrylonitrile can undergo addition polymerization under certain conditions.
(2) The addition polymerization takes place on the unsaturated bond.
(3) In the process of addition polymerization, no by-products are produced, and the chemical composition of the obtained polymer is the same as that of the monomer.
(4) The relative molecular weight of the polymer generated by the addition polymerization is an integral multiple of the relative molecular weight of the monomer.
Condensation polymerization is the abbreviation of condensation polymerization reaction, which refers to the polymerization reaction in which the monomer interacts with each other to generate macromolecules and also small molecules (such as water, ammonia, hydrogen halide, etc.).For example, the reaction of synthesizing phenolic resin is polycondensation.Phenolic resin is usually synthesized by condensation polymerization of phenol and formaldehyde under the action of catalyst.
The polycondensation reaction is divided into co polycondensation and homopolycondensation according to the number of monomers participating in the reaction. The polycondensation reaction involving different monomers is called co polycondensation.For example, the synthesis reaction of phenolic resin is co condensation, which consists of phenol and formaldehyde as monomers.The polycondensation reaction carried out by the same monomer is called homopolycondensation.For example, the polycondensation of amino acids into peptides is homogeneous polycondensation.
The characteristics of polycondensation reaction are:
(1) The monomer does not necessarily contain unsaturated bonds, but must contain two or more reaction groups (such as - OH, - COOH, - NHtwo, - X, etc.).
(2) As a result of polycondensation reaction, not only polymers are generated, but also by-products (small molecules) are generated.
(3) The chemical composition of the obtained polymer is different from that of the monomer.
It can be seen from the above that the monomer structure, reaction mechanism and chemical composition of products of addition polymerization and condensation polymerization are completely different.[3]
Experimental preparation
principle
Phenol and formaldehyde can form phenolic resin through condensation polymerization under the action of acidic or alkaline catalyst.Under the action of acid catalyst, linear thermoplastic resin is formed when phenol is excessive;Under the action of alkaline catalyst, the thermosetting resin is formed when the formaldehyde is excessive.
operation
(1) Add 4g of chemically pure phenol and 2.5mL of chemically pure formaldehyde solution (density: about 1.1g/cm3, concentration: 36~38%) into a 25 × 200mm test tube, and then add 1mL of chemically pure concentrated hydrochloric acid. After shaking evenly, plug a rubber stopper with a straight glass tube (300mm long).Fix the above test tubes on the iron stand and heat them in a water bath at 80~90 ℃ (as shown in the left figure).After a while, a violent reaction occurs in the test tube. After the reaction, continue heating until pink solid resin is generated.Take out the solid resin (hook it out with iron wire) and wash it with water to obtain thermoplastic resin.
(2) Add 2.5g of chemically pure phenol and 3mL of chemically pure formaldehyde solution (the same concentration as before) into a 25 × 200mm test tube, and then add 1mL of chemically pure concentrated ammonia water (the concentration is 25-28%). After shaking evenly, plug a rubber stopper with a straight glass tube (300mm long).Fix the above test tube on the iron stand and heat it with boiling water bath until the mixture is divided into two layers.When the viscosity of the resin at the bottom layer increases, remove the test tube and cool it with water, pour it out after the resin is cured, and wash it with water to obtain a yellow thermosetting resin.
explain
(1) The reaction of phenol and formaldehyde under alkaline condition is slower than that under acidic condition.To make the generated resin become solid after cooling, it must be heated for more than half an hour.
(2) Phenol and formaldehyde gradually form resin under alkaline conditions.The liquid that begins to form is a resin that is soluble in alcohol, acetone and alkaline aqueous solution, called Grade A resin.After continuous heating, viscous liquid will be generated, and after cooling, it will become a brittle solid, partially soluble in alcohol and acetone, but insoluble in alkaline aqueous solution.It is called Grade B resin (solid is softened by heat energy).Then continue heating to generate insoluble and unmelted resin, called Grade C resin.In the classroom teaching experiment, due to insufficient heating time, Grade B resin is generally generated.
(3) Phenol is toxic. Its concentrated solution is highly corrosive to the skin. Be careful when using it.If it touches the skin, immediately wipe it with alcohol.
(4) Phenol is a colorless crystal at room temperature, which is difficult to take out from the bottle.When using, put the bottle containing phenol in hot water at 60~70 ℃ to liquefy the crystal, suck it out with a long dropper, and drop it into a small beaker for weighing.[2]
Production technology
L. from 1905 to 1909H.BaekelandThe phenolic resin and its molding process were systematically studied. In 1910BerlinLuges Factory established a general phenolic resin company, realizingindustrial production 。In 1911, JW. Elsworth proposed to useHexamethylene tetramineCure the thermoplastic phenolic resin and prepare theplastic, has been widely used.In 1969, byU.S.AThe emery company has developed thefibre, followed byJapanJinuoer Company is put into production.Now in the United StatesSoviet UnionAnd China.The production of phenolic resin has not declined until now. In 1984, the total output of the world was about 1946kt, ranking first among thermosetting resins.China started production in the 1940s, and the output was 77.6kt in 1984.The commonly used raw materials for production methods are phenolresorcinol, m-cresolXylenol, p-tert-butyl or p-phenylphenol and formaldehydefurfuralEtc.The production process includes two steps: polycondensation and dehydration.Put the raw materials into the reactor according to the formula and mix evenly, add catalyst, stir, heat to 55~65 ℃, and the reaction heat will automatically raise the temperature of the materials to boiling.After that, continue heating to keep slight boiling (96~98 ℃) to the end point, and discharge after decompression and dehydration.A new process for continuous polycondensation of phenolic resin has been successfully developed.The main factor affecting the synthesis and properties of the resin is theChemical structure, molar ratio and pH of reaction medium.When the molar ratio of phenol to aldehyde is greater than or equal to 1productIt is monohydroxymethyl phenol, and linear resin is generated during polycondensation;When it is less than 1, a polyhydroxymethyl phenol derivative is generated, and the formed polycondensation resin can be crosslinked and cured.When the pH of the reaction medium is less than 7, the generated hydroxymethyl phenol is very unstable and easy to be condensed into linear resin;When pH is greater than 7, the polycondensation is slow, which is conducive to the formation of polyhydroxymethylphenol derivatives.Hydrochloric acid, phosphoric acid and oxalic acid are commonly used as catalysts for the production of thermoplastic phenolic resin (seeAcid base catalyst）Make the medium pH 0.5~1.5.In order to avoid violent boiling, the catalyst can be added in several times.The boiling reaction time is generally 3-6h.Dehydration can be carried out under normal pressure or reduced pressure, and the final dehydration temperature is 140~160 ℃molecular weight500~900.The production of thermosetting phenolic resin can use sodium hydroxide, barium hydroxide, ammonia and zinc oxide as catalysts. The boiling reaction time is 1~3h, the dehydration temperature is generally not more than 90 ℃, and the molecular weight of the resin is 500~1000.Strong base catalyst is beneficial to increase the hydroxymethyl content of resin and its solubility with water.Ammonia catalyst can directly participate in the resinification reaction. The resin prepared with the same formula has high molecular weight and poor water solubility.Zinc oxide catalyst can produce high ortho structure phenolic resin with good storage stability.
application area
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Phenolic resin is mainly used to manufacture various plastics, coatings, adhesives andSynthetic fibreEtc.
Compression molding powder
productionMoldingThe compression molding powder of products is one of the main uses of phenolic resin.The resin impregnated filler is mixed evenly with other additives by rolling, spiral extrusion and emulsion methods, and then crushed and sieved to produce compression molding powder.Wood powder is commonly used as filler. In order to manufacture some high electrical insulation and heat resistance products, mica powder, asbestos powder, quartz powder and other inorganic fillers are also used.Compression molding powder can be used for moldingTransfer moldingAnd injection molding into various plastic products.Thermoplastic phenolic resin compression molding powder is mainly used for manufacturingswitch, socket, plug, etcelectricalParts, daily necessities and other industrial products.Thermosetting phenolic resin molding powder is mainly used to manufacture high electrical insulation parts.enhancePhenolic plasticVarious fibers and fabrics impregnated with phenolic resin (mainly thermosetting phenolic resin) solution or emulsion, dried and pressedreinforced plastic It is an important industrial material.It not only has high mechanical strength and good comprehensive performance, but also can be machined.With glass fiberQuartz fibreThe phenolic plastic reinforced with its fabric is mainly used to manufacture various brake friction discs andchemical industryAnticorrosive plastic;High silica glass fiberAnd carbon fiber reinforced phenolic plasticAerospace industryImportant resistance ofAblative material。
Phenolic paintrosinThe modified phenolic resin, butyl alcohol etherified phenolic resin, p-tert-butyl phenolic resin and p-phenyl phenolic resin have good compatibility with tung oil and linseed oil, and are important raw materials for the coating industry.The first two are used to prepare low and intermediate gradepaintAnd the latter two are used to prepare advanced paint.
Phenolic adhesive
Thermosetting phenolic resin is also an important raw material for adhesives.Single phenolic resin is brittle, mainly used for bonding plywood and investment casting sand mold.Adhesives based on phenolic resin modified by other polymers play an important role in structural adhesives.Among them, phenolic butyronitrile, phenolic acetal, phenolic epoxy, phenolic epoxy acetal, phenolic nylon and other adhesives have the characteristics of good heat resistance and high bonding strength.Phenolic butyronitrile and phenolic acetal adhesives also have excellent properties such as tensile resistance, impact resistance, moisture and heat aging resistance. They areStructural adhesiveIt is an excellent variety.
Phenolic fibre
It is mainly made of thermoplastic linear phenolic resin and dipped inPolyoxymethyleneAnd hydrochloric acid aqueous solution to obtain formaldehyde crosslinked body structure fiber.To improveFibre strengthAnd modulus, which can be compared with 5%~10%polyamideMelting and spinning.This kind of fiber is golden yellow or yellowish brown, with strength of 11.5-15.9cN/dtex, outstanding flame resistance, limiting oxygen index of 34, instant contact with oxygen acetylene flame at nearly 7500 ℃, neither melting nor flame spreading, self extinguishing, and resistance to concentrated hydrochloric acid and hydrofluoric acid, but poor resistance to sulfuric acid, nitric acid and strong alkali.It is mainly used as protective clothing, flame resistant fabrics or indoor decorations, as well as insulation, heat insulation and heat insulation, filter materials, etc. It can also be processed into low strength and low modulus carbon fiber, activated carbon fiber andIon exchange fiberEtc.
Anticorrosive materials
Several forms of thermosetting phenolic resin commonly used in anti-corrosion field: phenolic resin coating;phenolic resinFRPPhenolic-epoxy resinComposite FRP;phenolic resinClayMortar;Phenolic resin impregnated, pressed graphite products.The curing forms of thermosetting phenolic resin can be divided into normal temperature curing and thermal curing.Curing at room temperature can use non-toxic room temperaturecuring agentNL，Benzenesulfonyl chloride or petroleum sulfonic acid can also be used, but the latter two materials are more toxic and irritating.It is recommended to use NL curing agent with low toxicity and high efficiency.Graphite powder, porcelain powder, quartz powder and barium sulfate powder can be selected as filler, but not suitablediabasePowder.
Thermal insulation materials
Mainly phenolic resinFoaming materialPhenolic foam products are characterized by heat insulation, heat insulation, fire prevention and light weight, and can be widely used as new materials for heat insulation, energy conservation and fire preventionCentral air conditioning systemLightweight thermal insulation color steel plate, building thermal insulation, energy reduction and thermal insulationChemical pipelineThermal insulation materials (especially deep and low temperature thermal insulation), vehicles and ships, etc.Phenolic foam is known as the king of thermal insulation because of its low thermal conductivity and good thermal insulation performance.Phenolic foam not only has low thermal conductivity and good thermal insulation performance, but also has fire resistance, good thermal stability, light weight, low smoke, low toxicity, heat resistance, high mechanical strength, sound insulation and resistanceChemical corrosionIt has many advantages, such as strong capacity, good weather resistance, etc. Phenolic foam plastic has abundant raw materials, low price, simple production and processing, and wide use of products.
Examples of phenolic resin applications:
example
formula
NBR modified phenolic plastics
PF molding compound is modified with solid nitrile rubber (NBA) to improve impact strength. Its basic formula is as follows:
PF resin 100
NBR rubber 25
Silicate filler 120
Lubricant 3.8
The impact strength of modified PF is 50% higher than that of unmodified PF
Liquid nitrile rubber can also be used to improve the thermal stability and toughness of PF, and can be used to manufacture friction materials.
It is also useful to add fiber while modifying carboxyl nitrile rubber.First, let nitrile rubber be grafted with bisphenol A epoxy resin, take 30 portions, and then add 100 portions of linear PF to prepare modified PF. At this time, the formula is:
The above modified PF 100
Hexamethylenetetramine 12
Wood flour 70
Polyvinyl alcohol fiber 15 (including 6 flocs in coarseness and 1 mm in length).
Zinc stearate 3
phenolic foam
PF foamed plastic is suitable for building materials such as thermal insulation materials. When burning, it does not melt, does not drip, emits less smoke, and does not produce carbon monoxide toxic gas.
80 ℃ foaming and curing, 10 minutes of sulfuric acid solution 10
Cure at 50 ℃ for 2 hours and then place at room temperature for 3 days
In addition, a large piece of cork oak bark is crushed, sieved, and baked at 180 ℃ to make cork particles, which are added to PF for foaming to replace cork bricks as thermal insulation materials.
Glass fiber reinforced phenolic resin
Formula: melamine phenolic acid 100
Alkali free glass fiber 88
Talc 33
The manufacturing process is as follows: adding talc powder into the modified PF, mixing evenly, adding glass fiber, blowing for 10 minutes in an oven at 100 ℃, and then pressing molding, with the temperature of 150 ℃, the pressure of 45 MPa, and the time of 15 minutes to prepare the reinforced PF material.
In addition, PF is modified by organosilicon, in which the addition amount of organosilicon is 20%, then 30-40mm glass fiber is added, the amount is 30%, the pressing temperature is 175 ℃, the pressure is 100 MPa, the time is 3 minutes, the post-treatment is 1501 ℃, 1 hour, then rises to 170 ℃, 2 hours, finally rises to 200 ℃, 1 hour.The product can be used as an aircraft plug seat part.
In addition to glass fiber, it can also be reinforced with vinylon fiber. For example, when 1.4 floc, 35 mm long vinylon, 70 parts, and 13 parts of hexamethylenetetramine are used, the PF effect is the best.
It also uses cotton fiber and silica powder to strengthen PF as bearing material.
The combination effect of fly ash and carbon black is good, which can improve the thermal stability of PF, but reduce the electrical performance. It can only be used as daily PF products, not electrical PF products.Among them, it is better to select high silicon aluminum for fly ash, which should be greater than 1.5 as far as possible.[4]
Storage and transportation
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Store in a cool and ventilated warehouse.The warehouse temperature should not exceed 37 ℃.Keep away from kindling and heat sources.Keep container sealed.It shall be stored separately from oxidant and shall not be mixed.Equip with corresponding types and quantities of fire-fighting equipment.
Hazard category
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(1) Flash point<23 ℃ and initial boiling point ≤ 35 ℃: flammable liquid, category 1
