Goldman Sachs Chemicals: Applications of p-phenylenediamine

　　Synthetic dyes and pigments

　　P-phenylenediamine is an intermediate of azo-based disperse dyes,acid dyes,direct dyes and sulfur dyes.Add 3%hydrogen peroxide to turn black,add 5%ferric chloride to turn brown.It has a strong affinity for keratin in hair,and its oxidation process is the process of fixing the color when dyeing hair.It is not only the most effective ingredient in hair dyes,but also the most potentially harmful substance to human health.

　　In the 1980s,there were 17 varieties using p-phenylenediamine according to CI.

　　Vulcanized light yellow GC(CI 5310)originally used benzidine as an intermediate.Because of carcinogenicity,the substitution of p-phenylenediamine by the Xinbin County Chemical Plant was successful.In other azo dyes using benzidine,p-phenylenediamine derivatives 4.4'-diaminodiphenylurea,4.4'-diaminodiphenylthiourea can also be used to replace benzidine(by p-phenylenediamine and urea and thiourea)synthesis).

　　Using p-phenylenediamine can also synthesize disazo condensation pigments,such as PR 166(Cr Scarlet R)and green sulfur dyes.

　　In addition,it is also possible to synthesize dyes and pigments with relatively good properties.

　　Synthetic resin

　　Aramid 1414(DuPont Kevlar)is obtained from the condensation of terephthalic acid or acid chloride with p-phenylenediamine,and has excellent performance.In the 1980s,the fiber was successfully used to make conductive fibers.Domestic Chenguang Chemical Research Institute has a pilot plant with an annual output of 3-5 tons of resin,and Yueyang Chemical Plant also has a pilot plant with an annual output of 20 tons of resin.In 1975,DuPont also developed polyimide resin NR-I50B2,which is formed by the condensation of hexafluorotetracarboxylic acid and mixed aromatic diamine(4.4'-diaminodiphenyl ether,p-phenylenediamine and m-phenylenediamine)It is widely used.The reaction of p-phenylenediamine with maleic rosin monoacid chloride can produce polyamide-imide resin with good performance,which can be formed into a film or can be drawn.It is a very practical resin.

　　Polyphenylene diamine and terephthalic acid chloride polycondensation polymer Kevlar,which belongs to high temperature polymer liquid crystal resin,is now used in supersonic aircraft composite materials.

　　Phenylenediamine reacts with phosgene to produce its diisocyanate(PPDI),which in turn produces highly crystalline polyurethane.The product has excellent high temperature performance,and can be used as a thermoplastic and castable elastomer.P-phenylenediamine reacts with aromatic dicarboxylic acids to form aromatic polyamides,which can be used to make fiber fabrics.They can be used as reinforcing materials for tires and V-tapes.They can be used as reinforced plastics,sports equipment,brake linings,etc.It is used in other articles requiring high strength and high modulus.

　　Rubber antioxidant

　　P-phenylenediamine and anti-aging agent synthesized with p-phenylenediamine as raw materials have good effect,and there are many varieties at home and abroad.It is mainly used as an antioxidant for natural rubber and diene synthetic rubber.

　　P-phenylenediamine can be directly used for the anti-aging of raw rubber.One example is the combination of p-phenylenediamine and organic acid cobalt salt for raw rubber.The raw rubber is used to produce steel wire tires,which overcomes the need to improve the bonding of steel wire and rubber.The aging problem caused by the addition of drilling salt during storage and vulcanization.

　　Condensate of p-phenylenediamine and furfural can also improve the adhesion between steel wire and rubber.

　　Condensation of p-phenylenediamine with octanol-2 or corresponding ketone gives Anti-aging 288.It is an excellent anti-ozonant.It is effective for aging caused by oxygen and deflection.It has protective effect against atmospheric cracking.It is suitable for natural rubber and synthetic rubber.In gasoline,it works better with N,N'-di-sec-butyl-p-phenylenediamine.There are seven or eight companies such as Monsanto in the United States.N,N'-Di-sec-butyl-p-diphenylenediamine is produced by the condensation of p-phenylenediamine and methyl ethyl ketone.The foreign trade name DBPB is both a rubber antioxidant and a petroleum antioxidant.

　　Epoxidized vegetable oil and p-phenylenediamine condensate,anti-aging performance is equivalent to 4010NA,but non-volatile,non-frosting,solvent resistance is better than 4010NA.

　　Polymeric anti-aging agent has excellent anti-aging properties,solvent resistance,non-volatile,no frost,one example is the condensation product of p-phenylenediamine and hydroquinone.

　　P-phenylenediamine anti-aging agent is the most effective anti-cracking agent and highly effective multi-functional anti-aging agent.N,N'-diaryl-p-phenylenediamine is the best antioxidant and anti-flex cracking agent,but its activity against ozone is low.N,N'-di-2-naphthyl-p-phenylenediamine is an excellent chain terminator and metal complexing agent.It has low pollution and good oxygen resistance and copper aging performance.N,N'-diarylbutyl-p-phenylenediamine has high anti-ozone activity and is an anti-ozonant for rubber and special polymers(such as polyamide).Asymmetric N-alkyl N'-phenyl-p-phenylenediamines are the best anti-flex cracking agents,good antioxidants,and have good comprehensive aging resistance,N,N'-di Methyl-p-phenylenediamine is used as an organic analysis reagent.

　　Epoxy resin curing agent

　　The use of p-phenylenediamine alone as an epoxy resin curing agent does not show any superiority,but the use of p-phenylenediamine modified phenolic resin to cure epoxy resin has good heat resistance and chemical resistance of cured products,The heat resistance is 50℃higher than the cured phenolic resin.

　　The reaction product of p-phenylenediamine and N-(4-hydroxy)maleimide and p-phenylenediamine and 2-amino-N-(hydroxyphenyl)succinimide as an epoxy resin curing agent,The cured products have glass transition temperatures of 227°C and 202°C,respectively,and can be used for printed circuit boards.The cured product of 4,4'-diaminodiphenyl sulfone has a glass transition temperature of 144°C.

　　Petroleum product additives

　　Condensate of p-phenylenediamine with dibutyl phosphate and dibutyl maleate,as a lubricating oil additive,the excellent anti-aging,fatigue and corrosion resistance performance under load of 1%.Condensate of p-phenylenediamine with ethylene oxide and propylene oxide,as a petroleum demulsifier,its performance is superior to Dissolvan4411.

　　P-phenylenediamine and sulfur,alkylphenol and paraformaldehyde condensate can be used as a detergent for gasoline and lubricating oil.

　　Carbon black treatment agent

　　Phenylenediamine-treated carbon black is used as the developer of zinc oxide-based electrophotographic photosensitive paper.The contact time is 0.3 seconds,the image contrast is sharp,and high-quality Kobe can be obtained.The carbon black treated with p-phenylenediamine can be used as a pigment to improve the blackness and the stability of the slurry,and can be used in inks to obtain products with excellent performance.

　　Processing insulation paper

　　Treating electrical insulating paper with p-phenylenediamine can improve heat resistance and reduce the loss of electrical and physical mechanical properties due to aging at 160°C.It can be used for the insulation of high-power turbine motors.

　　Flame retardant

　　The reaction product of p-phenylenediamine and tetrabromophthalic anhydride is used as flame retardant for low-density polyethylene.Adding 20%,the burning speed is reduced from 1.24 inch/min without flame retardant to 0.36 inch/min.The 3.0 inch down to 0.25 inch.

　　The reaction product of p-phenylenediamine and dichlorophenyl phosphate is used for the flame retardancy of polyimide glass cloth reinforced plastics.It is non-combustible at 2000°F(1093°C)for 15 minutes.

　　Other

　　Chelating resin produced by the reaction of p-phenylenediamine and EDTA anhydrous can be used to extract metals.

　　Phenylenediamine and aldehyde condensate can be used as anti-sticking agent for vinyl chloride polymerizer.The dosage is 0.01 g/m2,and the adhesion of polyvinyl chloride decreases by 40 times.

　　In addition,p-phenylenediamine is used for blood mark test,complex titration indicator,and used as ultrafine developer in combination with catechol.

　　The reactant of p-phenylenediamine and maleic anhydride was used as aquatic poison.After 6 months,the shellfish and algae attachment area was only 1%,and the attachment area ofthose who did not undergo the poison treatment reached 100%.

　　P-phenylenediamine can also be used as a crosslinking catalyst for the stabilized(with polymerization inhibitor)unsaturated polyester resin,etc.