Hydroxyl-terminated epichlorohydrin

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. 

Table 1. Functionality of Hydroxyl-Terminated Epichlorohydrin Liquid Polymers 3)...

Characterization of Hydroxyl-Terminated Liquid Polymers of Epichlorohydrin... 

The unreacted terminal epoxide groups can react with other diamine molecules to form a rigid network polymer. In this reaction the functionality of the bisphenol A-epichlorohydrin prepolymer 1-20 will be 2 since hydroxyl groups are not involved and the functionality of each epoxide group is one. 

Epoxides Structoset prepolymers are designed to have controlled and defined structures with functional groups located either at the chain-ends (structo-terminal) or located along the chain (structopendant). Epoxy resins make use of the epoxy group for the former, and hydroxyl groups for the latter. One of the major resin prepolymers formed by the reaction of bisphenol A and epichlorohydrin can be treated as either. 

A variety of terminal functional groups and their chemical transformations on SAMs have been examined for example, (i) olefins—oxidation [23,24,131,132], hydroboration, and halogenation [23,24] (ii) amines—silyla-tion [145,146], coupling with carboxylic acids [22,146], and condensation with aldehydes [22,147] (iii) hydroxyl groups—reactions with anhydrides [148,149], isocyanates [150], epichlorohydrin [151], and chlorosilanes [152] (iv) carboxylic acids—formation of acyl chlorides [153], mixed anhydrides [154], and activated esters [148,155] (v) carboxylic esters—reduction and hydrolysis [156] (vi) thiols and sulfides—oxidation to generate disulfides [157-159] and sulfoxides [160] and (vii) aldehydes—condensation with active amines [161], Nucleophilic... 

Polymerization proceeds by alternate formation of the oxonium salt of epichlorohydrin, followed by alkylation of the terminal hydroxyl of a growing polymer chain to produce polyepichlorohydrin having the structure... 

Ethyoxyline resins, now called epoxy resins, were patented by Schlack in 1939. Many of the prepolymers were versatile resins produced from the condensation of a diphenol (bisphenol A) and epichlorohydrin. Since these resins possess terminal oxirane (epoxy) groups, they can be crosslinked in reactions with polyamines at ordinary temperatures. These resins may also be crosslinked by esterifying the pendant hydroxyl groups by cyclic anydrides at elevated temperatures. 

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