Epichlorohydrin, polymerization with

Examples where the phenolic hydroxy groups were utilized include the preparation of lignin epoxies by reaction with epichlorohydrin (2), esterifications with bis-acid chlorides (3) and cyanuric chloride (4), and polymerization with aziridines (5). 

Frankel and coworkers at Rocketdyne [108] first synthesized PECH-triol by polymerization of epichlorohydrin (ECH) with glycerol as initiator followed by synthesis of GAP-triol [Structure (4.16)] as in Scheme 4.2. 

The mechanism of nonconventional bonding based on mixtures of diamines with PVC was explained (82) on the basis of the reported ability of the two materials to partially cross-link (180) (Scheme 3). Epichlorohydrin, used occasionally as an additive, polymerizes with polyfunctional amines (181) (Scheme 4) and reacts with lignin in the presence of amines or carboxylic acids (182). Even simpler to visualize is the cross-linking of the mixture of maleic anhydride and PVA by formation of ester linkages (118) that attach to the hydroxyls of the wood surface. 

Another type of activation of aluminum alkyl was found in the asymmetric-selective polymerization of epichlorohydrin (ECH) with an optically active cobalt-salen type complex [Co (II)]. The structure of the salen-type cobalt complex was shown previously (13, 14). In a benzene solution of the binary system consisting of [Co (II)] and AlEt, no evolution of ethane or ethylene was observed at room temperature. The NMR signals of the methyl protons for AlEt shifted down field on mixing with [Co (II)]. These observations together with a circular dichroism study indicated that AlEt and [Co (II)] formed a molecular complex in benzene, none of Al-Et bonds being cleaved by this complexation. 

Functional initiators were also used for the synthesis of macromonomers. Initiation of the polymerization of propylene oxide or epichlorohydrin (ECH) with hydroxyethylacrylate (or hydroxymethylmethacrylate) and BF3 OEt2 provided macromonomers with acrylate (or methacrylate) end-groups [183]. Subsequent radical copolymerization with S or MMA produced the graft copolymers PS-g-PPO, PS-g-PECH and PMMA-g-PECH. 

The concept of what is now called ste exclusion was developed by J. Porath and P. Flodin in 1959 and was called gel filtration. The gels they prepared were made from dextran that had been polymerized with epichlorohydrin and are known as Sephadex. They are prepared by what is now the Pharmacia Biotech Products Co., Uppsala, Sweden. Their structure is shown on p. 172. 

Melamine-formaldehyde-epichlorohydrin resin, useful for the separation of molybdenum and tungsten, has been prepared by treating melamine with formaldehyde at 60-65 °C and then condensing the reaction product with epichlorohydrin185). Polyethylenepolyamine has been polymerized with formaldehyde and phenol-epi-chlorohydrin or ammonia-epichlorohydrin reaction products to give anion-exchange lesins 186). Pretreatment of polyamine with semicarbazide or its salts increases the exchange capacity. 

We wish to stress this point because one can find examples of improper treatment of experimental data in the literature on cationic polymerization. For instance, in a recent paper on the polymerization of a-epichlorohydrin the authors observed limited conversions of monomer 21). The polymer yield was increasing with decreasing temperatures. The authors assumed that the monomer concentration at the plateau was the equilibrium monomer concentration, and calculated thermodynamic parameters . The ring strain, expressed by AH thus obtained for a-epichlorohydrin was unrealistically low (only —23 kJ mol-1) when compared with heats of polymerization of other 3-membered cyclic ethers (cf. Table 2.7). Other reports on a-epichlorohydrin polymerization have shown that nearly quantitative conversions are possible even at higher temperatures, provided that termination is suppressed22 23). 

Phenolphthalein (213) and its derivatives have found application in the polymer area. Phenol-phthalein itself (213) and substituted derivatives were polymerized with 2,6-dichlorobenzonitrile to form heat-resistant polycyanoaryl ethers <89JAP(K)01225631). A tetrabromo derivative (256) was polymerized with epichlorohydrin to form flame-retardant epoxy resins. The phthalide-derived... 

Lamot (117) prepared novel, non-nitrogen-containing compounds from calcium and diphenylethylene, (Ar) 2Ca, and then complexed the compounds with various amounts of epichlorohydrin, ECl, with tetrahydrofuran, or with a 1 0.7 mole ratio of epichlorohydrin to tetrahydrofuran. After preliminary testing of the complexes as initiators for polymerization of epichlorohy-... 

The boric and sulfuric acids are recycled to a HBF solution by reaction with CaF2. As a strong acid, fluoroboric acid is frequently used as an acid catalyst, eg, in synthesizing mixed polyol esters (29). This process provides an inexpensive route to confectioner s hard-butter compositions which are substitutes for cocoa butter in chocolate candies (see Chocolate and cocoa). Epichlorohydrin is polymerized in the presence of HBF for eventual conversion to polyglycidyl ethers (30) (see Chlorohydrins). A more concentrated solution, 61—71% HBF, catalyzes the addition of CO and water to olefins under pressure to form neo acids (31) (see Carboxylic acids). 

The majority of 2-methylphenol is used in the production of novolak phenoHc resins. High purity novolaks based on 2-methylphenol are used in photoresist appHcations (37). Novolaks based on 2-methylphenol are also epoxidized with epichlorohydrin, yielding epoxy resins after dehydrohalogenation, which are used as encapsulating resins in the electronics industry. Other uses of 2-methylphenol include its conversion to a dinitro compound, 4,6-dinitro-2-methylphenol [534-52-1] (DNOC), which is used as a herbicide (38). DNOC is also used to a limited extent as a polymerization inhibitor in the production of styrene, but this use is expected to decline because of concerns about the toxicity of the dinitro derivative. 

Allyl Glycidyl Ether. This ether is used mainly as a raw material for silane coupling agents and epichlorohydrin mbber. Epichlorohydrin mbber is synthesized by polymerizing the epoxy group of epichlorohydrin, ethylene oxide, propylene oxide, and aHyl glycidyl ether, AGE, with an aluminum alkyl catalyst (36). This mbber has high cold-resistance. 

The mechanism of chemical modification reactions of PS were determined using toluene as a model compound with EC in the presence of BF3-0(C2H5)2 catalyst and the kinetics and mechanism of the alkylation reaction were also determined under similar conditions [53-55]. The alkylation reaction of toluene, with epichlorohydrin, underwent polymerization of EC in the presence of Lewis acid catalysis at a low temperature (273 K) as depicted in Scheme (9). 

In contrast to the substituted PPO s, It Is theoretically possible to obtain the same substituted PECH s by homopolymerization of the corresponding mesogenic oxirane, or by its copolymerization with epichlorohydrin. We have attempted these polymerizations in order to better interpret the thermal behavior of the more complicated copolymers that we have obtained by polymer analogous reactions. Homopolymerization would be instructive because the incorporation of nonmesogenic units into liquid crystalline homopolymers doesn t as a rule change the type of mesophase obtained (5). 

Other polymerizations of commercial interest are the polymerizations of epichlorohydrin with aluminum or zinc alkyls with... 

The cationic ring-opening polymerization of epichlorohydrin in conjunction with a glycol or water as a modifier produced hydroxyl-terminated epichlorohydrin (HTE) liquid polymers (1-2). Hydroxyl-terminated polyethers of other alkylene oxides (3 4), oxetane and its derivatives (5 6), and copolymers of tetrahydrofuran (7-15) have also been reported. These hydroxyl-terminated polyethers are theoretically difunctional and used as reactive prepolymers. 

The reaction actually involves the sodium salt of bisphenol A since polymerization is carried out in the presence of an equivalent of sodium hydroxide. Reaction temperatures are in the range 50-95°C. Side reactions (hydrolysis of epichlorohydrin, reaction of epichlorohydrin with hydroxyl groups of polymer or impurities) as well as the stoichiometric ratio need to be controlled to produce a prepolymer with two epoxide end groups. Either liquid or solid prepolymers are produced by control of molecular weight typical values of n are less than 1 for liquid prepolymers and in the range 2-30 for solid prepolymers. 

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