Nickel Catalyst System Synthesizing High Cis 1,4-polybutadiene Were Studied

High cis 1, 4- polybutadiene rubber has the character such as outstanding resilience, excellent abrasion resistance, good heat resistance, low temperature properties,good resistance to light crazing, low hysteresis and excellent dynamic properties. High cis 1,4- polybutadiene is synthesized with nickel catalyst, which was first discovered by Macitomoki et al. in 1958. And thence the prelude of orientated polymerization of butadiene with nickel catalyst system was drawn back. Although more than 40 years have passed, a lot of scholars of all of the world are still studying new catalyst systems and techniques of confecting catalyst.In this paper, ZnEt₂ and MgBu₂ as the new agent introduced into the nickel catalyst system was studied. They can compose multiple alkylating agent with Al(i-Bu)₃ or be using as an alkylating agent along substitutiting Al(i-Bu)₃. Furthermore high Mooney viscosity high cis1,4-polybutadiene BR is synthesized with Ni-Al-B-ROH and then is charged oil, which is studied. And catalyst premix crafts are also studied.Polymerization kinetics and the chain transfer reaction were investigated by the use of dilatometers and polymerizing bottles, respectively. So the superficial velocity constant of pseudo-one order reaction and the apparent activation energy are gotten. The amplification polymerization is investigated by the use of a 5L batch reactor and one continuous polymerization equipment composed by three 40L reactors, so that the parameters which commercial pre-production need are obtained. Produced polymers were mainly characterized by infrared spectrometry , DSC and GPC. The microstructure, heat capability, molecular weight and distribution of the products synthesized by vary kinds of catalyst system are determined, tooAnd the mechanical abilities of cis1, 4- polybutadiene BR are examined.The experimental results indicate that ZnEt₂ and MgBu₂ in nickel catalyst system exhibits some different characteristics from Al(i-Bu)₃. When ZnEt₂ is added into the catalyst system, content of gel in the BR becomes lower; and the molecular weight distribution decreases and is controllable; but the velocity of polymerization is slow. When MgBu₂ is added into the catalyst system, velocity of polymerization increases remarkably, however content of cis1,4- structure decreases slightly. Adding ROH into the Ni-Al-B catalyst system, it can be used to preparing high cis1, 4-polybutadiene rubber with high Mooney viscosity. The experimental results indicate that the content of oil, time and temperature of oil charging will greatly influence abilities of resulting oil-extended rubber.Experiments of catalyst premix crafts indicate that design of reactor, order of adding catalysts, the proportion of the butadiene into premixing reactor and the residence time of material all greatly influence the activity of polymerization and abilities of BR. In the end, parameters of catalyst premix crafts and the process condition of commercial pre-production are obtained. Furthermore cisl, 4- polybutadiene robber with good menchanical capabilities and low gel is prepared.