25014-41-9 Usage
Description
Polyacrylonitrile (PAN) is a versatile, thermoplastic polymer belonging to the acrylic resin family. It is synthesized through the free radical polymerization of acrylonitrile and is characterized by its strong polar nitrile groups. PAN is known for its stability to UV degradation, low density, high strength and modulus of elasticity, thermal stability, non-fusibility, and chemical resistance. Due to these properties, it has a wide range of applications across various industries.
Uses
Used in Textile Industry:
Polyacrylonitrile is used as a textile fiber for its wool-like characteristics, making it suitable for producing outdoor awning, sails for yachts, and fiber-reinforced concrete.
Used in Carbon Fiber Production:
PAN is used as a polymeric carbon precursor to form carbon fibers, electrospun activated carbon materials with meso-macro pores, and carbon black additives. These materials are utilized in hydrogen storage, EMI shielding, electrochemistry, and separation processes.
Used in Filtration Membranes:
PAN is employed in the production of ultrafiltration membranes due to its chemical resistance and thermal stability.
Used in Cement Reinforcement:
Polyacrylonitrile fibers are used for cement reinforcement, enhancing the strength and durability of the material.
Used in Yacht Sails and Outdoor Applications:
PAN is used in the manufacturing of sails for yachts and awning fabrics for outdoor applications, taking advantage of its resistance to UV degradation and weather conditions.
Used in Acoustic and Thermal Insulation:
Specialist fibers made from PAN are utilized for acoustic and thermal insulation due to their high thermal insulation properties and resistance to breakages.
Used in Flame-Retardant Fabrics:
Inherently flame-resistant (FR) fabrics are produced using PAN homopolymer fibers, making them suitable for outdoor awning, sails, and fiber-reinforced concrete.
Used in Automobile Industry:
Poly(acrylonitrile-co-butadiene-co-styrene) (ABS) and Poly(styrene-co-acrylonitrile) (SAN) are used as plastics in the automobile industry for producing lightweight and strong automobile body parts, contributing to fuel efficiency and reduced pollution.
Used in Hot Air Filtration Systems:
PAN copolymers, which are flame-retardant, are used as fibers to make knitted clothing like socks and sweaters, as well as outdoor products like tents and felts for hot air filtration systems.
Used in Single-Walled Carbon Nanotube Composites:
PAN may find applications in PAN-based single-walled carbon nanotube composites, further expanding its use in various industries.
References
https://www.britannica.com/science/polyacrylonitrile
https://en.wikipedia.org/wiki/Polyacrylonitrile
Preparation
Approximately 70% of the commercial output of acrylonitrile is polymerized
(with minor amounts of comonomers) to give polymers which are used for
textile fibres:The most important methods for the preparation of polyacrylonitrile are
solution polymerization and suspension polymerization. The former method
is particularly convenient, since when a solvent for the polymer is used, the resulting solution may be utilized directly for fibre spinning. Concentrated
aqueous solutions of inorganic salts such as calcium thiocyanate, sodium
perchlorate and zinc chloride make suitable solvents; suitable organic solvents include dimethylacetamide, dimethylformamide and dimethylsulphoxide. Emulsion polymerization suffers from the disadvantage that the monomer has appreciable water-solubility and the formation of polymer in the
aqueous phase can lead to coagulation of the latex. This tendency is reduced
by the addition of ethylene dichloride to the system.
Fibres prepared from straight polyacrylonitrile are difficult to dye and, in
order to improve dyeability, commercial fibres invariably contain a minor
proportion (about 10%) of one or two comonomers such as methylmethacrylate, vinyl acetate and 2-vinylpyridine.The average molecular weight (Mw) of commercial polyacrylonitrile is
generally in the range 80000-170000.
In polyacrylonitrile appreciable electrostatic forces occur between the
dipoles of adjacent nitrile groups on the same polymer molecule. This
intramolecular interaction restricts bond rotation and leads to a stiff chain.
As a result, polyacrylonitrile has a very high crystalline melting point (317°C)
and is soluble in only a few solvents such as dimethylacetamide and dimethylformamide and in aqueous solutions of inorganic salts. Polyacrylonitrile
cannot be melt processed since extensive decomposition occurs before any
appreciable flow occurs and fibres are therefore spun from solution. In one
process, for example, a solution of the polymer in dimethylformamide is
extruded into a coagulating bath of glycerol and the fibre formed is drawn
and wound.Polyacrylonitrile is unstable at elevated temperatures. On heating above about 200°C, polyacrylonitrile yields a red solid with
very little formation of volatile products. When the red residue is heated at
about 350°C there is produced a brittle black material of high thermal
stability. The first step in these changes consists of a nitrile polymerization
reaction whilst the second step involves aromatization to form a condensed
polypyridine ladder polymer:Continued heating at high temperatures (1500-3000°C) results in the elimination of all elements other than carbon to leave a carbon fibre with graphitic crystalline structure of great strength. Polyacrylonitrile fibres have become
the most important source for carbon fibres. Polyacrylonitrile is hydrolysed by heating with concentrated aqueous
sodium hydroxide to poly(sodium acrylate).
Purification Methods
Precipitate it from dimethylformamide by addition of MeOH.
Check Digit Verification of cas no
The CAS Registry Mumber 25014-41-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,5,0,1 and 4 respectively; the second part has 2 digits, 4 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 25014-41:
(7*2)+(6*5)+(5*0)+(4*1)+(3*4)+(2*4)+(1*1)=69
69 % 10 = 9
So 25014-41-9 is a valid CAS Registry Number.
25014-41-9Relevant articles and documents
Experimental Evidence for the Existence of Cyanovinylidene :C=C(H)CN. Gas-Phase Characterization of a Possible Interstellar Molecule
Goldberg, Norman,Schwarz, Helmut
, p. 3080 - 3082 (1994)
Experiments on the first successful gas-phase generation of the theoretically predicted cyanovinylidene :C=C(H)CN are reported by applying the technique of neutralization-reionization mass spectrometry.
METHOD FOR PRODUCING NITRILE
-
Paragraph 0080; 0090; 0093-0094, (2021/02/05)
The present invention provides a method of producing a nitrile from a primary amide, characterized in that the primary amide is subjected to a dehydration reaction in a supercritical fluid in the presence of an acid catalyst. The present invention achieves the object of reducing the corrosion of a reactor and the thermal decomposition of raw materials, as well as provides the effect of improving the reaction rate and nitrile selectivity.
Facile dehydration of primary amides to nitriles catalyzed by lead salts: The anionic ligand matters
Ruan, Shixiang,Ruan, Jiancheng,Chen, Xinzhi,Zhou, Shaodong
, (2020/12/09)
The synthesis of nitrile under mild conditions was achieved via dehydration of primary amide using lead salts as catalyst. The reaction processes were intensified by not only adding surfactant but also continuously removing the only by-product, water from the system. Both aliphatic and aromatic nitriles can be prepared in this manner with moderate to excellent yields. The reaction mechanisms were obtained with high-level quantum chemical calculations, and the crucial role the anionic ligand plays in the transformations were revealed.
