Prediction of the lifetime of nitrile-butadiene rubber by FT-IR.
A quantitative measurement method with FT-IR was proposed for a thermal degradation analysis of nitrile-butadiene rubber (NBR). An NBR film was prepared as a model sample on a barium fluoride (BaF2) crystal plate, which was subjected to a heat treatment. The absorbances of various functional groups were measured directly by FT-IR after thermal degradation at high temperatures. By measuring the absorbances, it was possible to readily determine quantitatively each of the functional groups after the degradation of NBR. By assuming that the NBR lifetime was the point at which the absorbance of a carbon-carbon double bond reaches 45% of that prior to thermal treatment, a method for predicting the lifetime of NBR heated below 150 degrees C was proposed, by using an Arrhenius plot of the heating time versus heating temperature.
Spectroscopy of Polymers
Chapter headings and selected papers: Theory of Polymer Characterization. Elements of polymer structure. Structural model of the polymer chain. Relating the polymer structure to the polymerization mechanism. The shape of things to come. Vibrational Spectroscopy of Polymers. Introduction to vibrational spectroscopy. Vibrational spectroscopy as an identification tool. Raman selection rules. Experimental IR Spectroscopy of Polymers. Infrared spectroscopic instrumentation. Sampling methods for IR spectroscopy. Data processing of digitized IR spectra. Quantitative IR spectroscopy of polymers. Applications of IR spectroscopy to Polymers. Copolymer analysis. Conformational analysis of polymers. Where do we go from here? Raman Spectroscopy of Polymers. Experimental Raman spectroscopy. Degradation of polymers. Conformation of polymers in solution and in the melt. High Resolution NMR Spectroscopy of Polymers in Solution. Elements of nuclear magnetic resonance spectroscopy. Nuclear spin relaxation. Magnetic interactions between nuclei. Applications of High Resolution Solution NMR. Determination of end group structure. Determination of branching polyethylene. Determination of copolymer structure. High-Resolution NMR Spectroscopy of Solid Polymers. The dipolar-decoupling experiment (DD). Chemical-shift anisotropy (CSA) in solids. Experimental implementation of cross-polarization. Applications of High-Resolution Solid-State NMR Spectroscopy to Polymers. Chemical shifts in the solid state. Mass Spectrometry of Polymers. MS instrumentation. Mass analyzer. Electrical detection.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.