| 释义 |
preˈpolymer
[pre- B. 1.]
An intermediate in a process of polymerization which is convenient for manipulation and can be fully polymerized at a later stage in the process.
1956Mod. Plastics July 111/3 If this thickening process is interrupted at the appropriate point, the prepolymer or sirup has about the same consistency as molasses (in June, not January!). 1962New Scientist 25 Oct. 205/1 The state of polymerization of special synthetic fluids such as aviation turbine oils or polypropylene glycol (the latter a prepolymer used in the manufacture of polyurethane foams). 1971Penrose Ann. LXIV. 23 The second [solventless ink] system uses liquid photo-sensitive pre-polymers which are polymerized and solidified immediately by exposure to high doses of ultra-violet light. 1978Sci. Amer. June 107/1 The third method of consolidating stone is to treat it with organic monomers and prepolymers.
So preˌpolymeriˈzation; preˈpolymerize v. trans., to convert (a monomer) into a prepolymer.
1949B. L. Davies Technol. Plastics ix. 151 If the prepolymerization of the resin is carried too far, the flow in the mould is restricted so that only a limited range of mouldings can be produced. 1956Mod. Plastics July 111/3 (heading) Prepolymerization. Ibid. 114/1 Thermosetting resins cannot be prepolymerized to any useful degree in this manner, since they set up to a firm gel at a relatively low degree of cure. 1967Margerison & East Introd. Polymer Chem. iv. 200 If all traces of inhibitors..are not removed from the monomer, irreproducible rates of polymerization are often found; for this reason it is the practice to ‘pre-polymerize’ 1 or 2% of the monomer before use. |