9010-98-4 Usage
Chemical Properties
white to beige chips or chunks
History
Polychloroprene was discovered in 1930 at E. I. DuPont de Nemours & Co. inWilmington Delaware. The discovery grew out of a need to develop a synthetic substitute for natural rubber. DuPont first marketed this first commercially successful synthetic elastomer as DuPrene in 1933. In response to new technology development that significantly improved the product and manufacturing process, the name was changed to Neoprene in 1936. The current commercially acceptable generic name for this class of chlorinated elastomers is CR or chloroprene rubber.
polychloroprene structure
Uses
Polychloroprene is a (Solid) Mechanical rubber products, lining oil-loading hose and reaction equipment, adhesive cement, binder for rocket fuels, coatings for electric wiring, gaskets and seals. (Liquid) Specialty items made by dipping or electrophoresis from the latex. (Foam) Adhesive tape to replace metal fasteners for automotive accessories, seat cushions, carpet backing, sealant
Definition
ChEBI: A macromolecule composed of repeating (2Z)-2-chlorobut-2-ene-1,4-diyl units.
Production Methods
Commercial polychloroprene rubber is manufactured by aqueous free-radical emulsion polymerization followed by isolation of the solid polymer by one of several processes: freeze roll isolation, drum drying , extruder isolation, precipitation and drying or spray drying. Isolation of powdered polychloroprene has been reviewed. Of the methods cited, freeze roll and drum drying isolation are commercially important.
The large-scale commercial manufacture of polychloroprene consists of eight or nine unit operations:
(1) Monomer solution makeup Water solution makeup
(2) Emulsification
(3) Polymerization
(4) Stripping of residual monomer
(5) Peptization for chloroprene–sulfur copolymers
(6) Freeze roll isolation Drum drying
(7) Drying of freeze-rolled film
(8) Roping
(9) Cutting and packaging (25kg)
Preparation
Polychloroprene is made from one of two starting materials, acetylene or butadiene. Acetylene can be dimerized and then chloronated to form chloroprene. Alternatively, when adequate butadiene is available, this can be directly halogenated (eqs. 7 and 8). In either case, the chloroprene product can then be polymerized to polychloroprene. Essentially a butadiene elastomer with chlorine present in the backbone,the polymer exhibits excellent tensile strength and low hysteresis, much like natural rubber. Tensile strength properties up to 28 MPa are possible with the proper reinforcing system (see FILLERS). The polarity imparted by the chlorine atom improves the oil and solvent resistance approaching those of nitrile polymers. The polymer can be protected with para-phenylenediamine antiozonants to give ozone resistance, and heat aging is also good. As a result, chloroprene elastomers are used in a wide variety of applications needing a balance of such properties.
Hazard
Questionable carcinogen.
Industrial uses
One of the first synthetic rubbers used commercially to the rubber industry, neoprene is a polymer of chloroprene, 2-chlorobutadiene- 1,3. In the manufacturing process, acetylene, the basic raw material, is dimerized to vinylacetylene and then hydrochlorinated to the chloroprene monomer. Sulfur is used to vulcanize some types of neoprene, but most of the neoprenes are vulcanized by the addition of basic oxides such as magnesium oxide and zinc oxide. The cure proceeds through reaction of the metal oxide with the tertiary allylic chlorine that arises from the small amount of 1,2-polymerization that occurs. Other compounding and processing techniques follow similar procedures and use the same equipment as for natural rubber. One of the outstanding characteristics of neoprene is the good tensile strength without the addition of carbon black filler. This versatility makes them useful in many applications requiring oil, weather, abrasion, or electrical resistance or combinations of these properties, such as wire and cable, hose, belts, molded and extruded goods, soles and heels, and adhesives.
Materials Uses
The most widely used contact adhesive is a solution of polychloroprene or modified polychloroprene in solvent blends of aromatic hydrocarbons, aliphatic hydrocarbons, esters, or ketones, for example, toluene–hexane–acetone. Viscosity, dry time needed before bonding, bond strength, and price are affected by the solvent. Using various combinations of the isomeric forms of polymerized 2- chlorobutadiene permits a fine-tuning of the crystallization rate of the dissolved polymer as the solvent evaporates. The polychloroprene may also be modified by the incorporation of methacrylic acid or mercaptans. Metal oxides (MgO and ZnO) that scavenge acids are often part of polychloroprene adhesives and also may act as cross-linking agents. Oxygen scavengers such as butylated hydroxytoluene (BHT) [128-37-0] or naphthylamines [25168-10-9] are added to prevent dehydrochlorination. To build initial handling strength, the solvent-based polychloroprene contact adhesives may be modified with alkyl phenolics, terpene phenolics, or phenolic-modified rosin esters, the first of these being the most effective and least deleterious. Chlorinated rubbers are sometimes added to these adhesives to improve their adhesion to plasticized PVC and other plastics. Added just before adhesive application, isocyanates are useful in modification of polychloroprene contact adhesives, reacting perhaps through hydrolysis of the pendant allylic groups present from the small number of 1,2 isomeric segments. The remainder of the solvent-based contact adhesives are comprised of polyurethane, SBR, styrene–butadiene–styrene block polymers, butadiene–acrylonitrile rubber, natural rubber, or various acrylic or vinyl resins in suitable solvents.
Check Digit Verification of cas no
The CAS Registry Mumber 9010-98-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 9,0,1 and 0 respectively; the second part has 2 digits, 9 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 9010-98:
(6*9)+(5*0)+(4*1)+(3*0)+(2*9)+(1*8)=84
84 % 10 = 4
So 9010-98-4 is a valid CAS Registry Number.
9010-98-4Relevant articles and documents
Addition of Chloroprene Grignards to Aromatic Aldehydes: Synthesis of Homoallenyl Alcohols
Geissler, Arne G. A.,Breit, Bernhard
supporting information, p. 2621 - 2625 (2021/04/12)
A general procedure for the one-pot synthesis of racemic homoallenyl alcohols from the corresponding aldehyde and chloroprene-derived Grignards is described. Employing bis[2-dimethylaminoethyl]ether (BDMAEE) as an additive at low temperatures shifts the selectivity of the chloroprene Grignard addition to aldehydes such that it is almost exclusive toward allene formation. In a set of follow-up experiments, simple and more elaborate methods for further derivatization have been demonstrated, allowing quick access to more complex structures.
Thermal ring opening of 1,1-dibromo and 1-bromo-2- chloromethylcyclopropanes: Observation of a formal debromochlorination
Sydnes, Leiv K.,Alnes, Karl F. S.,Pettersen, Anita,Brinker, Udo H.
experimental part, p. 479 - 483 (2010/06/16)
When the title compounds are thermolyzed in the gas phase under vacuum or in hot quinoline, several products are formed. A predominant product in all cases is a chlorine-free buta-1,3-diene which has been formed by formal debromochlorination, a reaction n
Synthesis of the potent anticancer agents ottelione A and ottelione B in both racemic and natural optically pure forms
Clive, Derrick L. J.,Liu, Dazhan
, p. 3078 - 3087 (2008/09/19)
(Chemical Equation Presented) The powerful antitumor agents ottelione A and B were synthesized in racemic form by a method that relies on selective ring closing metathesis. Optically pure natural (+)-ottelione A was then made from D-ribose, via an α-keto cyclopropane. A key feature of the route is that the cyclopropyl group controls the stereochemistry in the attachment of the ArCH2 unit and is then converted by the action of SmI2 into a vinyl group, so that the substituents on the resulting five-membered ring have the required trans relationship. Epimerization of an intermediate gave access by the same method to the trans ring fused isomer (-)-ottelione B.
