摘要 |
Polyolefins are prepared by vapour phase pyrolysis of an aldehyde haloether addition product using a molecular sieve. Pyrolysis of the addition product of olefin (I)/haloether (II) in the vapour phase in the presence of a molecular sieve gives the polyolefin (isoprene), a haloacid and an alcohol. (II) (chloromethyl methyl ether) is prepared by reaction of a haloacid, an alcohol and an aldehyde. (I) may be isobutylene. (I) and (II) are produced at the hourly wt. rate of 0.1 to 10. Pressure during pyrolysis is 0.1-10 atm. and temp. is 75-500 degrees C. The process gives improved yield and makes recovery of the polyolefin easier. The haloacid and alcohol can be recycled to form (II). |