Magnetic nanoparticles are known to generate heat when exposed to an alternating external magnetic field. A multi‐scale model for the heat generation by magnetic nanoparticles embedded in an elastomeric material has been developed. The model affords the determination of the unsteady‐state temperature profiles in the particles and in the surrounding polymeric medium by numerically solving the equation of energy. We obtained the complete thermal history of the system as a function of all relevant parameters including particle size, particle volume fraction, thermal properties of the particle and the medium, and details of the imposed magnetic field. The predicted results are in good agreement with experimental data obtained on liquid crystalline elastomers.

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An infrared method based on the 5.88 μ absorption was developed for the analysis of ethylidenenorbornene in EPDM. The method was calibrated using a VPC analysis for unreacted monomer and by the addition of dichlorocarbene followed by an elemental analysis for chlorine. A check by NMR on a selected sample showed good agreement with the other methods.

synopsisThe effect of various aluminum alkyls at varying concentrations on the rate and stereospecificity of propylene polymerizations with titanium trichloride was examined. It was concluded that diakylaluminum halides were merely chemisorbed on the surface of the titanium trichloride while the trialkylaluminums reacted more extensively with the surface. I n the case of diethylaluminum chloride standard chemisorption kinetics were observed. The rate of polymerization was also found to be a function of solvent, with certain aromatic solvents causing significant rate increases. With diethylaluminum chloride essentially no-termination occurs; the polymers are "living polymers."