Epichlorohydrin degradation

Small FJ, JK Tilley, SA Ensign (1995) Characterization of a new pathway for epichlorohydrin degradation by whole cells of Xanthobacter strain Py2. Appl Environ Microbiol 61 1507-1513. 

Degradation of epichlorohydrin (l-chloro-2,3-epoxypropane) may proceed by hydrolysis of the epoxide to 3-chloro-l,2-propanediol that is then converted successively into... 

Van den Wijngaard AJ, DB Janssen, B Withold (1989) Degradation of epichlorohydrin and halohydrins by bacterial cultures isolated from freshwater sediment. J Gen Microbiol 135 2199-2208. 

The degradation of 1,2,3-trichloropropane by Agrobacterium radiobacter strain ADI involves hydrolysis of an intermediate epichlorohydrin (3-chloroprop-l-ene) to the diol (Bosma et al. 1999, 2002). An enzyme from this strain has been modified from the use of epichlorohydrin that is its normal substrate to accept dy-l,2-dichloroethene with the release of chloride and the presumptive formation of glyoxal (Rui et al. 2004). 

Epoxy resin can have varying amounts of inorganic material remaining in the product after its synthesis. One of these is sodium chloride, which is formed by the reaction of sodium hydroxide with epichlorohydrin molecules, as described in Chap. 2. This is important in electrical applications because the sodium salt can be hydrolyzed and can degrade electrical properties. Some epoxy resin manufacturers will offer special ultrapure electrical grades or low-chlorine grades of epoxy resins for application where this is an important factor. 

Lead stabilisers have been used in a variety of PVC as well as other polymers for many years. In some halogenated polymers, such as chlorinated PE (CPE), chlorosulphonated polyethylene (CSM), polychloroprene (CR) and epichlorohydrin (ECO), dibasic lead phthalate and dibasic lead phosphite are used to scavenge HC1 arising from crosslinking as well as from degradation. In some of these cases, the metal may participate in crosslink formation. With lead-based stabilisers, the result is typically a product with greater water and chemical resistance than if a light metal, with more soluble halide salts, were used instead. In other cases, lead stabilisers may be used solely for function in metal oxide... 

The aforementioned poly(aminoamides) can be subjected to additional derivatization reactions. Some potential reactions include reaction with epichlorohydrin (to generate reactive functionalities), degradation of the polyamide chain (for repulping purposes), reaction with Quat 188 (to add pendant quatemaiy ammonium groups to the polymer chain), and reaction with 1,3-dichloropropane (to increase the molecular weight and to crosslink the polymer). 

The first two fractions are produced either in a nitrogen atmosphere or under vacuum at 70 Pa (0.5mmHg). Accurate quantification requires appropriate corrections to allow for the overlap of the process oil and resins with the polymer decomposition region along with the serious complication observed for elastomers with a heteroatom in the monomer unit like acrylonitrile-butadiene, chloro-prene rubber, chlorobutyl rubber, polyvinyl chloride (PVC), chlorosulfonated polyethylene, polyacrylates, fluoroelastomers, epichlorohydrin rubbei etc. Most of these polymers produce volatile components below 300°C and leave a carbonaceous residue after degradation, which oxidizes with the carbon black... 

Irritative, low-MW degradation products may be produced in the tooling of epoxy products and in heating processes (Engstrom and Henriks-Eckerman 1988). Amine and anhydride hardeners and epi-chlorohydrin irritate the skin and conjunctivae. In addition to causing irritant contact dermatitis, epi-chlorohydrin, as a highly reactive compound, and aliphatic polyamines, as highly alkaline compounds (pH 13-14), can cause corrosive burns on the skin (Ippen and Mathies 1970 Adams 1983). Ippen and Mathies (1970) described protracted chemical burns minutes or several hours after the exposure of five patients to epichlorohydrin. 

The copolyesters resistance to nonoxidizing acids, some aliphatic hydrocarbons, aromatic fuels, hot oils, and hydraulic fluids ranges from good to excellent. Thus, they compete with such rubbers as nitriles, epichlorohydrins, and acrylates. However, hot polar materials, strong mineral acids and bases, and chlorinated solvents and creosols degrade the copolyesters. Their weather resistance is low but can be improved considerably, with UV stabilizers and carbon-black additives. 

---