Diene polymers and copolymers terminated with compounds having multiple-bonded nitrogen atoms and partially crosslinked with polyfunctional reagents

A method for preparing a diene polymer or copolymer having improved processability and adapted to form elastomer compositions having reduced hysteresis properties comprising the steps in sequence of:

• (1) preparing a living diene polymer or copolymer containing active organoalkali or organoalkaline earth metal terminals by anionically polymerizing a conjugated diene monomer or mixture of a conjugated diene monomer and vinyl aromatic hydrocarbon monomer in a hydrocarbon solvent using an organoalkali metal or organoalkaline earth metal initiator;
• (2) terminating substantially all of the living diene polymer or copolymer chains by reacting the organoalkali or organoalkaline earth metal terminal thereof with from about 0.6 to about 2 moles of a compound having multiple-bonded nitrogen atoms selected from the groups consisting of aromatic nitriles and substituted imines having the formula:
• ##STR10## wherein R.sub.1 and R.sub.2 are selected from the group consisting of H, alkyl, cycloalkyl, aryl, dialkylaminoaryl, aralkyl and aprotic O, N and S--containing alkyl, cycloalkyl, aryl and aralkyl groups;
• wherein R.sub.3 is selected from the group consisting of alkyl, cycloalkyl, aryl, dialkylaminoaryl, aralkyl and aprotic O, N, and S--containing alkyl, cycloalkyl, aryl and aralkyl groups;
• with the proviso that at least one of the R.sub.1, R.sub.2 and R.sub.3 groups must be a dialkylaminoaryl group and that not all of the R.sub.1, R.sub.2 and R.sub.3 groups can be aryl groups;
• and
• (3) coupling from about 10 to about 70 percent by weight of the terminated polymer chains with a polyfunctional reagent selected from the group consisting of silicon polyhalides, polyisocyanates, phosphoryl halides and polycarboxylic acid halides.