Rubber-to-steel adhesives based on natural rubber grafted with poly(acetoacetoxyethyl methacrylate)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rattanawadee Ninjan ◽  
Bencha Thongnuanchan ◽  
Natinee Lopattananon ◽  
Anoma Thitithammawong ◽  
Charoen Nakason

Abstract The present study aimed to develop adhesives for bonding natural rubber (NR) to steel based on modified NR bearing grafted poly(acetoacetoxyethyl methacrylate), NR-g-PAAEM. Graft copolymers of NR-g-PAAEMs were prepared by emulsion polymerization at 50 °C. A significant increase in the polar component of NR from 1.62 to 6.84 mN/m was observed after grafting modification, indicating an increase in its hydrophilicity. After that, both one-coat and two-coat adhesives (or adhesive/cover-coat system) were then prepared, using polyisocyanate (poly‐HDI) as a bonding agent. The NR/steel joints were made by vulcanization bonding, using the NR-g-PAAEM adhesive in the presence or absence of cover-coat layer. The results reveal that the NR/steel joint bonded using the two-coat system exhibited higher peel strength than that bonded using the one-coat system. For the two-coat system, the peel strength of 874 N/m was attained when the NR-g-PAAEM adhesive was used in combination with the NR cover-coat. The replacement of the NR cover-coat by the NR-g-PAAEM20 cover-coat led to 49% increase in peel strength of the NR/steel joint. Moreover, the X-ray photoelectron spectroscopy analysis also indicated the formation of urethane-like bonding in this adhesive system, as a result of the reaction between the poly‐HDI and metal oxides on the steel surface.

2012 ◽  
Vol 1376 ◽  
Author(s):  
P. Silva-Bermudez ◽  
S. Muhl ◽  
M. Rivera ◽  
S. E. Rodil

ABSTRACTIn the present work, the adsorption of albumin and fibrinogen on Ta, Nb, Ti and Zr oxidesthin films deposited on Si (100) wafers by magnetron sputtering was studied in order to get a better understanding of the correlation among the surface properties of these oxides and the protein adsorption phenomena on their surfaces. The surface energy, hydrophobicity, chemical composition, roughness and atomic order of the films were characterized. The films were immersedfor 45 minutes in single protein solutions; either albumin or fibrinogenand the adsorbed protein layer on the films was studied ex-situ in a dry ambient using bothX-ray photoelectron spectroscopy and atomic force microscopy.The adsorption of albumin and fibrinogen on the films modified the surface morphology and decreased the surface roughness for all the four different metal oxides. The XPS results confirmed the presence of the protein on the surface of the films and showed that the two proteins studied were adsorbed without undergoing a major chemical decomposition. A correlation between the surface roughness,the polar component of the surface energy of the films and the atomic percentage of nitrogen on the films after protein adsorption, an indirect signal of the amount of protein adsorbed, was found for albumin and fibrinogen adsorption on Ta, Nb and Ti oxides; the largest the roughness or the polar component the largest amount of adsorbed protein.


NANO ◽  
2019 ◽  
Vol 14 (07) ◽  
pp. 1950084 ◽  
Author(s):  
Jilong Wang ◽  
Siheng Su ◽  
Jingjing Qiu ◽  
Shiren Wang

In this paper, a novel and facile method to achieve fluorescent nanosized-diamond based nanowire (NW) is reported. One-dimensional (1D) organic NW has received tremendous attention due to its superior chemical functionality and size-, shape-, and material-dependent properties. In addition, nanosized-diamond is comprehensively studied and investigated due to superior tunable fluorescent properties, cost-effectiveness, facile manufacturing and high biocompatibility. Through thermal treatment, sulfur-modified nanosized-diamond was fabricated by mixing oxidized nanosized-diamond and dibenzyl disulfide at 900∘C. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and zeta potential were employed to characterize sulfur-modified nanosized-diamond. After that, porous anodic aluminum oxide template-assisted cathodic electrophoretic deposition method was used to achieve sulfur-modified nanosized-diamond NW. Scanning electron microscopy and transmission electron microscopy were applied to present the one-dimensional structure of the NWs. The optical properties of sulfur nanosized-diamond NW were characterized via ultraviolet-visible spectroscopy and photoluminescence spectroscopy. Finally, the as-synthesized sulfur-modified nanosized-diamond NW-based optical sensor was fabricated to detect vitamin B[Formula: see text] with high sensitivity and selectivity.


2002 ◽  
Vol 16 (2) ◽  
pp. 115-120 ◽  
Author(s):  
César Augusto Galvão Arrais ◽  
Marcelo Giannini

The formation of a hybrid layer is the main bonding mechanism of current dentin-bonding systems. This study evaluated the morphology and thickness of the resin-infiltrated dentinal layer after the application of adhesive systems. The dentin-bonding agents were evaluated on flat dentinal preparations confected on the occlusal surfaces of human teeth. The test specimens were prepared and inspected under scanning electron microscopy at a magnification of X 2,000. The adhesive systems were responsible for different hybrid layer thicknesses (p < 0.05), and the mean values were: for Scotchbond MP Plus (SM), 7.41 ± 1.24mum; for Single Bond (SB), 5.55 ± 0.82mum; for Etch & Prime 3.0 (EP), 3.86 ± 1.17mum; and for Clearfil SE Bond (CB), 1.22 ± 0.45mum. The results suggest that the conventional three-step adhesive system (SM) was responsible for the thickest hybrid layer, followed by the one-bottle adhesive (SB). The self-etching adhesives, EP and CB, produced the formation of the thinnest hybrid layers.


2004 ◽  
Vol 12 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Linda Wang ◽  
Marília Afonso Rabelo Buzalaf ◽  
Maria Teresa Atta

A dhesive systems associated to resin-modified glass ionomer cements are employed for the achievement of a higher bond strength to dentin. Despite this benefit, other properties should not be damaged. This study aimed at evaluating the short-time fluoride release of a resin-modified glass ionomer cement coated with two one-bottle adhesive systems in a pH cycling system. Four combinations were investigated: G1: Vitremer (V); G2: Vitremer + Primer (VP); G3: Vitremer + Single Bond (VSB) and G4: Vitremer + Prime & Bond 2.1 (VPB). SB is a fluoride-free and PB is a fluoride-containing system. After preparation of the Vitremer specimens, two coats of the selected adhesive system were carefully applied and light-cured. Specimens were immersed in demineralizing solution for 6 hours followed by immersion in remineralizing solution for 18 hours, totalizing the 15-day cycle. All groups released fluoride in a similar pattern, with a greater release in the beginning and decreasing with time. VP showed the greatest fluoride release, followed by V, with no statistical difference. VSB and VPB released less fluoride compared to V and VP, with statistical difference. Regardless the one-bottle adhesive system, application of coating decreased the fluoride release from the resin-modified glass ionomer cements. This suggests that this combination would reduce the beneficial effect of the restorative material to the walls around the restoration.


NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650064 ◽  
Author(s):  
Jia-Ying Xin ◽  
Hong-Chen Fan ◽  
Sheng-Fu Ji ◽  
Yan Wang ◽  
Chun-Gu Xia

The development of palladium nanoparticles (PdNPs) with a narrow size distribution is an important aspect of nanotechnology. Methanobactin (Mb) is a copper-binding small peptide that appears to function as an agent for copper sequestration and uptake in methanotrophs. Here, Mb was shown to bind and catalytically reduce Pd (II) to Pd (0). The one-step synthesis of monodisperse PdNPs using Mb as both coordination agent and reduction agent is reported. Fluorescence spectra, UV-visible spectra, X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR) suggested that the Mb molecules catalytically reduce Pd (II) to Pd (0) with the concomitant production of PdNPs. The Mb is then adsorbed onto the surface of the PdNPs to form an Mb–PdNPs coordination compound. This avoids secondary nucleation. The PdNPs are small with high monodispersity and are easily synthesized in Mb solution. The PdNPs were extremely stable and resisted aggregation even after several months.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1901
Author(s):  
Pengfei He ◽  
Wenfeng Du ◽  
Longxuan Wang ◽  
Ravi Kiran ◽  
Mijia Yang

Additive Manufacturing (AM) technology has unique advantages in producing complex joints in architecturally exposed steel structures. This article focuses on the process of manufacturing and investigating the mechanical properties of a reduced scale model of a trifurcated joint using Selective Laser Melting (SLM) method and mechanical tests, respectively. The orthogonal test method was used to optimize the main AM process parameters. Then the trifurcated steel joint was printed using the optimal process parameters and treated by solid solution and aging treatment. To investigate the mechanical performance of the printed joint, an axial compression test and complimentary finite element analyses were carried out. Failure processes and failure mechanisms of the trifurcated steel joint were discussed in detail. The research results show that the preferred process parameters for printing 316L stainless steel powder are: scanning power 150 W, scanning speed 700 mm/s, and scanning pitch 0.09 mm. Using these AM parameters, trifurcated steel joints with good surface quality, geometrical accuracy and tensile strength are obtained after heat treatment. Our mechanical tests and Finite element analyses results indicate that the failure mechanism in the AM trifurcated joint are similar to those of cast steel joints. Based on these results, we conclude that the AM technology serves as a promising new way for the fabrication of joints with complex geometries.


1971 ◽  
Vol 49 (7) ◽  
pp. 1135-1136 ◽  
Author(s):  
A. B. Cornford ◽  
D. C. Frost ◽  
F. G. Herring ◽  
C. A. McDowell

The ionization potentials of the methyl amines down to 20 eV binding energy, have been determined by photoelectron spectroscopy, and are compared with those predicted by i.n.d.o.-l.c.a.o.-s.c.f. theory. The first ionization potential for each compound refers to the removal of an electron from the lone pair, and is shown to be the one most affected by the inclusion of one center repulsion integrals in the i.n.d.o. calculations.


2018 ◽  
Vol 165 ◽  
pp. 22004 ◽  
Author(s):  
Thomas Balutch ◽  
Bertrand Huneau ◽  
Yann Marco ◽  
Pierre Charrier ◽  
Clément Champy

For some automotive anti-vibration applications, for instance exhaust hangers, center bearing bushes or torsional vibration dampers, temperature constraints make the use of synthetic rubbers, such as EPDM, necessary because of their better heat aging resistance compared to natural rubber. The aim of this paper is to understand the features of the fatigue behaviour of an industrial EPDM compared to the wellknown natural rubber. To do so, fatigue tests are conducted on hourglass-shaped specimens, and fracture surfaces are analysed using optical microscopy and scanning electron microscopy (SEM). It appears that every samples exhibit only one root cause of failure. Thus, two types of precursors are identified as responsible of the final fracture of samples: material’s inclusions and mold flaws. Interrupted fatigue tests are then performed and fatigued samples are observed with SEM. The built procedure allows us to follow fatigue cracks initiation and propagation along cycles, and to propose local damage mechanisms for each type of precursors. A global damage scenario is finally considered and compared to the one of natural rubber described in the literature.


RSC Advances ◽  
2016 ◽  
Vol 6 (108) ◽  
pp. 107021-107028 ◽  
Author(s):  
Ran Wang ◽  
Hua Mei ◽  
Wentan Ren ◽  
Yong Zhang

A novel polymer was synthesized via a grafting reaction of epoxidized natural rubber (ENR) with poly(ethylene glycol) monomethylether carboxylic acid (mPEG-COOH), which can improve the conductivity as a matrix of CPE.


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