Telechelic Polyethylene

Abstract

Ethylene may be converted to polymer of 3, 100–15, 000 number average molecular weight by dialkylperoxydicarbonate-initiated polymerization in aqueous silver Perchlorate solution at 0-40°C and l–20 bar. The narrow molecular weight distribution $\left( {{{\bar M}_w}{{\bar M}_n} = 2.5 - 3.0} \right)$ suggests that there is little long-chain branching in the polymier, but the density, melting point and infrared spectrum show that the polymer carries 5–10 methyl groups (short-chain branches) per thousand backbone carbon atoms. Hydroxylterminated polyethylene may be prepared by saponifying dialkylperoxydicarbonate-initiated polymer; the hydroxylterminated product is telechelic and will condense with phosgene to yield a polycarbonate having molecular weight several times larger than the starting material. These results contrast sharply with the report that peroxydicarbonate initiation in the absence of silver ion yields product which is essentially monofunctional and has much lower molecular weight. The telechelic character of polymer prepared in silver Perchlorate solution can be explained by oxidation of growing polyethylene radicals by hyper-oxidized silver ions.