The Malaysian Rubber Producers Research Association

Other

David S Campbell

Andrew J Tinker

Charles C Mosher

Iain M Mason

Geoffrey M Jackson

David E Loeber

Delman Lee

Peter G Mente

A method of seismic surveying uses seismic waveguides in the earth. Seismic energy is transmitted from outside the waveguide and detected within the waveguide or vice-versa. Coupling of energy between the outside and the inside of the waveguide is effected by energy leakage at coupling sites where the waveguide departs from planarity. The method analyzes seismic signals to determine the position and nature of coupling sites and the propagation characteristics of the waveguide.

Seismic surveying

A hydroxyl-functional polymer is reacted with a compound ZCO.N(H).sub.x.N(H).sub.x.CO.OR, where Z is halogen or aryloxy, x is 0 or 1 and R is hydrocarbon, and the reaction product is if necessary oxidized to give an azodicarboxylate functional polymer having the formula QOCO.N:N.CO.OR where Q is an inert polymer group. This polymer is used to react with ethylenically unsaturated natural or synthetic rubber so as to graft groups derived from the polymer on the rubber backbone.

Reagents for graft copolymers

Graft copolymers having thermoplastic elastomeric properties are formed by intimately blending together at elevated temperature in the solid state in e.g. an internal mixer (a) an ethylenically unsaturated natural or synthetic rubber and (b) a pre-polymer of a vinyl aromatic monomer having an azodicarboxylate end group reactive towards unsaturated groups of the rubber.

Method of forming graft copolymers by attaching pre-polymerized side

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Welwyn, United Kingdom

David S Campbell