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13C‐NMR has been used to examine a number of dichlorocarbene adducts of cis‐ and trans‐polybutadiene prepared in a two‐phase system. Dichlorocarbene was generated by reaction of aqueous or solid NaOH or KOH with CHCl3 in the presence of a phase transfer catalyst. Monomer compositions, comonomer sequence lengths, and stereochemical information were obtained for the resulting polymers. The polymers examined here were stereochemically pure and were treated as simple copolymers. Samples prepared using aqueous NaOH can be described as essentially random copolymers over the entire range of monomer composition. Samples prepared using solid alkali‐metal hydroxides contain a higher fraction of blocked units than a polymer of comparable composition prepared using aqueous NaOH. This blockiness can coincide with the presence of two glass transition temperatures and a two‐phase morphology as seen by transmission electron microscopy. Fractionation of a substantially blocked sample yielded a chlorine‐poor fraction which was a random copolymer and a chlorine‐rich fraction which was more blocked than the original unfractionated material.

The kinetics for the cycloaddition of dichlorocarbene to cis‐1,4‐polybutadiene (BR) have been examined for aqueous and solid sodium hydroxide–chloroform mixtures containing 350 molecular weight α‐methyl‐ω‐hydroxy‐poly(oxy‐1,2‐ethanediyl) (Carbowax 350) as a phase transfer catalyst. This study describes the influence of reaction variables on rate and the partitioning of dichlorocarbene between dichlorocyclopropanation and hydrolysis. The results are consistent with a kinetic model derived for the case where mass transfer is not rate limiting. However, this does not apply at high conversions where mass transfer control occurs due to large increases in viscosity. Higher BR concentrations can be achieved by replacing chloroform with methylene chloride containing stoichiometric amounts of chloroform. This mass action effect causes more favorable partitioning toward cyclopropanation; otherwise, chloroform and methylene chloride behave similarly as solvents. Water is an essential component in this reaction because it greatly increases the ability of the catalyst to extract sodium hydroxide into the organic phase.

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I have not gone into compounding and testing results on polyisoprene and polybutadiene. As you well know, they are widely used in the rubber industry. From a technical standpoint, we know we can replace natural rubber with cis-polyisoprene. However, the profitability of the process is closely tied to the availability of isoprene monomer and the price ratio of cis-polyisoprene and natural rubber. Sometimes the economics is favorable and sometimes unfavorable. Consequently, polyisoprene expansion is slow in the Free World. In the Communist countries, however, the planned economy is pushing ahead with polyisoprene—projections for 1985 are for 817 000 metric tons versus 227 000 metric tons in the Free World. Is there a possibility of an entirely new synthetic rubber that will be the equal of polyisoprene, but more economical? Is there a blend of elastomers that will replace natural? Is there a chance the economics of polyisoprene might become more favorable? Certainly the answers pose a challenge to those of us in research. We cannot sit back and say we have reached the ultimate, for the world of the tire is constantly changing, and we must be able to meet the change. The work reported here could not have been carried out without the invaluable contributions of my colleagues at BFGoodrich. I wish to especially mention: Jim Shipman and Jack Kiehl for the early infrared work and claiming that I was trying to fool them with my first copolymer; Vern Folt, the enthusiastic section leader for the early project ; Earl Carlson, who elucidated the conditions for making trans-polyisoprene and trans-polybutadiene ; Dave Craig for supplying the pure isoprene for the early work; Bob Minchak and Harold Tucker for some of the cobalt studies and titanium studies; Harvey Scott for the cobalt chloridealuminum chloridethiophene catalyst; Ed Wilson and M. Reinhart for compounding studies; Waldo Semon and Carlin Gibbs for directing it all and allowing us such a free hand; Floyd Miller, who did such an outstanding job of scaling the process directly from a 50 g lab recipe to production size runs; and the numerous, capable technicians who have worked for me— they are the unsung heroes of the laboratory work. Let me say again how highly honored I feel to receive this award. I am accepting it for all at BFGoodrich, for it was truly a team effort.