Fabrication of novel hindered phenol/phenol resin/nitrile butadiene rubber hybrids and their long‐period damping properties

Abstract

To overcome the modification shortcoming of phenol resin (PR) in decreasing the loss factor peak (tan δmax) of nitrile butadiene rubber (PR/NBR) blends, the hindered phenol AO‐80/PR/NBR hybrids were successfully prepared. The tan δmax of the hybrids is found to increase with the increment of AO‐80 content while they almost remains the same widths of damping temperature range as PR/NBR blend. Their damping properties can be regulated well by controlling the content of AO‐80. Various experimental data of Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and dynamic viscoelastic measurements (DMAs) show that the good damping properties of the hybrids result from the cooperative effect of two different relaxation transitions: the hydrogen bonds of nitrile group associated with hydroxyl group of AO‐80 besides their glass transition. The effect does not decrease the width of damping temperature range of the hybrids but really maintain a high value of tan δmax in a long duration; but it is found that the components of hybrids with the high content of AO‐80 become partly compatible after long‐period storage. So the content of AO‐80 is important to sustain the damping storage stability for NBR hybrids where the amount of AO‐80 below 50 phr is preferred. We believe that our studies provide some basic observations to serve the practical applications of NBR hybrids. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Influence of hydrogen bonding interaction on the damping properties of poly(n‐butyl methacrylate)/small molecule hybrids

“…[4][5][6][7][8] Using hydrogen bonds between small molecules and polymers to increase the damping property of hybrid materials presents infinite prospects for the manufacturing industry. 9,10 However, the influence of hydrogen bond interaction, including the strength and number of hydrogen bonds of the hybrid system, on damping properties remains unclear. Optimal selection of small molecules is also difficult to achieve because of the various structure and properties of small molecules.…”

Preparation and characterization of low-temperature hydrogenated nitrile butadiene rubber hybrid with hydrogen bonds for the sealing applications

“…For example, Zhang et al reported that the AO-80 played the role of nanofillers to reinforce the NBR; moreover, the damping properties of their hybrids were greatly enhanced by lots of AO-80 [20]. Most literatures have stressed the possible damping usage of rubber hybrids with great amounts of FOSM [21,22]. As a result, it is confirmed that the hydrogen bond of fillers has important effects on the properties of rubbers.…”

“…Careful examination for the band of C@O groups (belongs to hydrogen bond I) at the wavenumber range of 1700-1800 cm À1 displays that there is a single absorption at 1728 cm À1 . By comparison with double peak of pure (crystal) AO-80 [20,21,32], this suggests that the crystal structures of AO-80 have been damaged by rubber chains after the preparation and then the hydrogen bonds of AO-80 become intermolecular ones. With the increase of AO-80 amounts, the absorption barely shifts although their intensities decrease a little, implying the numbers of hydrogen bond I are reduced.…”

“…By referring to [21], the topography and phase of cryogenically fractured surface in the as-prepared hybrids were examined by atomic force microscopy (AFM, Dimension 3100, Veeco Instruments Inc., USA) in tapping mode.…”

Phenolic vulcanization of butadiene nitrile rubber. 1. Investigation of mechanism of vulcanization by infrared spectroscopy

“…В ряде работ приводятся разные механизмы вулканизации каучуков фенолоформальдегидными смолами [11][12][13][14][15][16]. Таким образом, установление механизма вулканизации для конкретных типов и марок каучуков, и фенолоформальдегидных смол, используемых в производстве композиционных фрикционных материалов, является важным фактором повышения качества и эксплуатационных характеристик фрикционных узлов трения.…”