Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Patent
1974-02-19
1976-06-29
Henderson, Jr., Christopher A.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
220 1R, 260 942M, 427239, 428 35, 526174, 526180, 526217, 526339, 526340, C08D 120, C08D 308
Patent
active
039666913
ABSTRACT:
A linear conjugated diene of 4 to 8 carbon atoms or a mixture of such conjugated dienes or a mixture of such a conjugated diene and a vinyl aromatic monomer is polymerized in a monomer-starved process to yield homopolymers of copolymers of low molecular weight containing as low as 35 and up to 90 or 95% or more of microcyclic structures, if properly catalyzed and depending upon the temperature and other conditions of the reaction. These microcylic structures are defined as microcyclic rings of molecules containing 6 to 18 or more alkylene units. These cyclic structures are produced by the monomer-starved process which causes the bond between the carbon and the metal to bite back on itself. The catalyst used in the production of these microcylic polymers is a combination of (1) zero-valent lithium, sodium or potassium metals or an alkyl derivative thereof, preferably in combination with (2) a chelating tert-diamine, such as N,N,N',N'-tetramethylene diamine, spartein or a bicyclic amine such as DABCO (1,4-diazabicyclo[2,2,2]octane). Thus, when the catalyst is only lithium, sodium or potassium or an organo derivative thereof, due to the starved catalyst procedure more or less of the polymer is cyclized, depending upon the temperature and other conditions of the reaction. If a chelating diamine is also used as catalyst, an increased amount of cyclized polymer is present in the product. If the catalyst also includes an alkoxide of an alkali metal different from the alkali metal previously mentioned, a higher per cent of cyclized polymer is formed, such as perhaps 40 to 60 per cent or more. The invention includes solid polymer which contains sufficient cyclized units to produce very low shrinkage during curing in the mold; and includes such molding processes. A variety of products of different molecular weights, etc. can be produced.
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Henderson, Jr. Christopher A.
The Firestone Tire & Rubber & Company
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