Abstract

Abstract Prepolymer technology is a relatively new science in which polymer structures of any desired type are built from partially polymerized liquid resins containing reactive functional groups. Well over one hundred low molecular weight polymers and crosslinking agents are currently available commercially. The first examples were the liquid phenolic casting resins which appeared in the mid 1930's. Unsaturated polyester-styrene mixtures were available by 1945 followed shortly by the epoxide resins and the liquid polysulfides. Today the chemist or engineer can chose among a wide assortment of liquid polymers: Polymer chain : Polyester, polyether, polyamide, polysulfide, polybutadiene, polyisobutylene Reactive group: Carboxyl, hydroxyl, sulfhydryl, amine, epoxide, isocyanate, olefin These liquid polymers may be separated into two types: those in which the reactive groups are randomly distributed along the backbone chain and those in which the functional groups are located at the ends of the chains. It is the latter with which this discussion is concerned, in particular with the functionally terminated polybutadienes. Uraneck, Hsieh, and Buck have coined the word “telechelic” for polymer molecules having two reactive terminal groups and we will use this term. The word derives from the Greek tele, far off, and chele, claw.

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