A series of hydrogenated natural rubbers, HNRs, were prepared by homogenous hydrogenation using H 2 gas with a rhodium catalyst (chlorotris(triphenylphosphine)rhodium) in toluene. The HNRs were linear polymers with molecular weights greater than 800,000. These rubbers were vulcanized using sulfur and peroxide compounds. Vulcanized 100% HNR has a low glass transition temperature (T g ¼ À438C) and excellent abrasion resistance, and is resistant to oxidation and ozonolysis ageing.

The complex reflectance function of acoustic waves in the incidence angle range from 0 to 60° was calculated for polymer thin films on glass substrates with different Young's modulus and density values. A characteristic phase change of the complex reflectance function was observed due to the existence of the polystyrene thin film on the glass substrate. The phase change appeared when the thickness of the polymer thin film was more than 0.9 µm at 300 MHz. The normalized wave number of the characteristic phase change varied sensitively with Young's modulus and the density of the polymer thin film. The contour map of the normalized wave number was obtained from these results. The determination method of Young's modulus of the polymer thin film by the characteristic phase change was proposed.

Polyurethane-imide elastomers (PUIEs) are formed from isocyanate, polyol, acid anhydride, and diamine by liquid polymerization. Unfortunately, many of the diamines have rarely been applied to the formation of PUIEs. Hence, investigating the effect of diamines on PUIEs remains a challenge in polymer chemistry. Herein, PUIEs prepared from 4,4'-diphenylmethane diisocyanate (MDI), polytetramethylene glycol (Mw: 1000), pyromellitic dianhydride, and aromatic diamines (such as p-phenylene diamine, 4,4'-oxydianiline, and 1,3-bis(4-aminophenoxy)benzene), and aliphatic diamines (such as 1,2-ethylene diamine, 1,6-hexamethylene diamine, and 1,12-dodecamethylene diamine) were synthesized by liquid polymerization. The morphologies and the chemical, thermal, and mechanical properties of the various PUIEs were investigated. The obtained elastomeric sheets were characterized in terms of the following tests and methods: solubility and swelling tests, X-ray diffraction and differential scanning calorimetry, dynamic mechanical analysis and thermogravimetric analysis, tensile tests, nuclear magnetic resonance spectroscopy, infrared spectroscopy, atomic force microscopy, contact angle microscopy, and scanning electron microscopy.

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