Integrated Calendar

Optical measurements have been used for more than a century as proxies for properties of marine particles. In this presentation we will review how sediments affect in-water and remotely sensed optical properties and how that effect has been used to infer information about sediment concentration, characteristics and dynamical processes associated with sediments (e.g., resuspension, settling, aggregation and disaggregation).

In weakly coordinating solvents containing LiCB11(CH3)12 and a radical initiator, terminal alkenes have been reported to polymerize, and standard tests suggest that the process involves a radical mechanism. This highly surprising observation has been examined more closely using a most improbable alkene candidate for radical polymerization, isobutylene.

It is shown that previously unknown branched polyisobutylene is formed under non-oxidizing conditions, whereas under oxidizing conditions a mixture of the latter with carborate-attached linear polyisobutylene is obtained. The two polymers can be separated by solvent extraction. Polymerization results and properties of resulting polymers are described. And two different polymerization mechanisms (radical versus cationic) are discussed for the formation of each fraction.

An investigation into the polymerization of isobutylene initiated by CB11Me12• radical in the presence of LiCB11Me12 suggests possible hydrogen abstraction from the backbone of the polyisobutylene chain followed by grafting. Grafting of linear polyisobutylene, as well as small organic molecules such as THF, tetramethylpentane and benzene by isobutylene and maleic anhydride are presented.

In addtion, copolymerization of olefins with polar comonomers is discussed.