| 摘要 |
<p>Olefinic polymers may be converted to hydroxy functional polymers of lower molecular weight by converting a portion of the olefinic bonds of the polymer to ozonide linkages and reductively cleaving the thus produced ozonide linkages to produce a hydroxy functional polymer. The ozonization may be effected by passing ozone, preferably mixed with a gaseous carrier such as oxygen, through a solution of the polymeric material in a solvent such as chloroform in an amount such that one mol. of ozone is introduced for each two to six unsaturated repeating units of the polymeric starting material. The resulting ozonide is recovered and then reduced and cleaved by reaction with a strong reducing agent, preferably a hydride of a light metal such as lithium hydride, aluminium hydride or lithium aluminium hydride. Preferably the reducing agent is added to a solution of the ozonide cooled below room temperature until present in excess and the reaction mixture is then warmed until reductive cleavage occurs. The preferred polymers treated according to the invention are stereo regular polymers which include natural materials such as rubber, balata and gutta-percha. In the example, a cis-1,4-polybutadiene prepared using a Ziegler-Natta catalyst is treated according to the invention.</p> |
