Vulcanization of Butyl Rubber: Curative Effects of 2-Pentadecylbenzoquinonedioxime

1981 ◽  
Vol 54 (4) ◽  
pp. 692-697 ◽  
Author(s):  
N. D. Ghatge ◽  
N. N. Maldar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Butyl Rubber ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Rubber Vulcanizate ◽  
Aging Study ◽  
Red Lead ◽  
Good Retention

Abstract The structure-property relationships of butyl rubber vulcanizates derived from quinonedioxime-red lead or quinonedioxime-MBTS-sulfur cure systems were studied. The effects of the dioxime curatives on the mechanical properties of the elastomer are discussed on the basis of rheological and heat-aging study. It was found that a 2-pentadecylbenzoquinonedioxime-MBTS-sulfur cured butyl rubber vulcanizate shows good retention of tensile strength on heat aging at 125°C.

Mechanical Behavior of Rigid Rod Polymeric Fibers

1988 ◽  
Vol 134 ◽  
Author(s):  
Steven R. Allen ◽  
Richard J. Farris
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Tensile Modulus ◽  
Structure Property ◽  
Polymeric Fibers ◽  
Shear Moduli ◽  
Structure Property Relationships ◽  
Secondary Interactions ◽  
Rigid Rod

ABSTRACTPoly-(p-phenylene benzobisthiazole) fibers provide a model system for the evaluation of structure-property relationships in extended-chain polymeric fibers. Owing to the poorly developed lateral order in as-spun fibers, the enhancement of structural perfection and of mechanical properties may be examined through heat treatment processing more readily than with more crystalline fibers. High tensile modulus (to 300 GPa) and high tensile strength (3 GPa) have been obtained from heat treatment processing of the fibers. The development of tensile modulus and tensile strength depends directly on the enhancement of overall axial molecular orientation. Tensile strength is additionally dominated by the development of stronger lateral molecular interaction. The mechanical properties mimic the inherent chain anisotropy arising from strong primary bonding along the chain and much weaker secondary interactions between chains. Tensile to shear moduli ratios of 200:1, tensile to shear strength ratios of 50:1 and tensile to compressive strength ratios of 10:1 are observed.

Mechanical and Viscoelastic Characterization of Hyperbranched Polyisobutylenes

2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt
Keyword(s):  
Molecular Weight ◽  
Butyl Rubber ◽  
Structure Property ◽  
Carbocationic Polymerization ◽  
Molecular Weights ◽  
Structure Property Relationships ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Living Carbocationic Polymerization

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.

QSPR STUDY OF RHEOLOGICAL AND MECHANICAL PROPERTIES OF CHLOROPRENE RUBBER ACCELERATORS

2014 ◽  
Vol 87 (2) ◽  
pp. 219-238 ◽  
Author(s):  
Roberto Todeschini ◽  
Viviana Consonni ◽  
Davide Ballabio ◽  
Andrea Mauri ◽  
Matteo Cassotti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mathematical Models ◽  
Structural Features ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Quantitative Structure Property Relationships ◽  
Cure Time ◽  
Chloroprene Rubber ◽  
Experimental Values ◽  
Rubber Accelerators

ABSTRACT In this preliminary study, mathematical models based on Quantitative Structure Property Relationships (QSPR) were applied in order to analyze how molecular structure of chloroprene rubber accelerators relates to their rheological and mechanical properties. QSPR models were developed in order to disclose which structural features mainly affect the mechanism of vulcanization. In such a way QSPR can help in a faster and more parsimonious design of new chloroprene rubber curative molecules. Regression mathematical models were calibrated on two rheological properties (scorch time and optimum cure time) and three mechanical properties (modulus 100%, hardness, and elongation at break). Models were calculated using experimental values of 14 accelerators belonging to diverse chemical classes and validated by means of different strategies. All the derived models gave a good degree of fitting (R2 values ranging from 84.5 to 98.7) and a satisfactory predictive power. Moreover, some hypotheses on the correlations between specific structural features and the analyzed rheological and mechanical properties were drawn. Owing to the relatively small set of accelerators used to calibrate the models, these hypotheses should be further investigated and proved.

The Effect of Second Filler on Cure Characteristic and Mechanical Properties of Si-69 Treated Precipitate Silica/NR Composite

2009 ◽  
Vol 79-82 ◽  
pp. 2183-2186 ◽  
Author(s):  
Chanchai Thongpin ◽  
C. Sripetdee ◽  
N. Papaka ◽  
N. Pongsathornviwa ◽  
Narongrit Sombatsompop
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Rubber Compound ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Rubber Vulcanizate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Cure Characteristic

Silica has been widely used as non-black reinforcing filler, however, the filler-filler interaction has been an important issue. Cure characteristic and mechanical properties of the rubber compound and rubber vulcanizate were affected both by filler-rubber interaction and filler-filler interaction. There have been, presently, a number of natural fillers which are also used as fillers for the rubber, i.e. fly ash, sawdust and zeolite. This work therefore will study the effect of second filler added into the 13% Si-69 treated precipitate silica (PSi) filled natural rubber compounds. It was revealed that the scorch and cure time of the rubber compound increased with the content of treated PSi. This was the effect of excess of the silane treated onto PSi which would agglomerate and form the cluster of polysiloxane and would then be able to absorb vulcanizing accelerator resulting in extending the scorch and cure time of the rubber compounds. However, this effect was over ruled with the reinforcing effect as could be seen by the increasing, with the contents of PSi, of maximum torque and mechanical properties of the vulcanizates. The NR compounded with treated PSi content of 20 phr selected to study the effect of excess silane on the cure characteristic of hybrid fillers NR composite. The addition of sawdust led to longer scorch time and cure time but not much change of the maximum torque. As expected, the modulus of the rubber vulcanizate increased with the sawdust content whereas the tensile strength and elongation at break decreased with the sawdust content. The incorporation of zeolite could accelerate the cure reaction therefore both scorch time and cure time decreased. The maximum torque also increased with the content of zeolite. Both modulus and tensile strength increased with the content of the zeolite whereas elongation at break tended to be unchanged. In the case of using fly ash as the second filler, the cure time tended to be unchanged. However, the maximum torque tended to be increased with the content of fly ash. It was found that the modulus, tensile strength increased but elongation at break decreased. Interestingly, the excess of Si-69 used effect pronouncedly for the addition of zeolite and fly ash cases as the excess silane could promote the interaction between fillers surface and rubber molecule accept for sawdust

scholarly journals Study the impact of A nanomixture of carbon black and clay on the mechanical properties of A series of irradiated natural rubber/ butyl rubber blend

2021 ◽  
Author(s):  
Dalal Alshangiti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Theoretical Models ◽  
Butyl Rubber ◽  
Nano Particles ◽  
Vinyl Silane ◽  
Link Density ◽  
The Impact

Abstract A series of natural rubber/ butyl rubber NR/IIR blend loaded with N660 carbon black CB and triethoxy vinyl silane treated clay nano particles (TCNP) were prepared using gamma irradiation in the presence of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). The effect of incorporating different content of N660 carbon black and 5 part per hundred of rubber (phr) of treated clay on the mechanical properties of the prepared nano composites have been investigated. The additions of TCNP into CB/ rubber composites markedly increase their tensile strength due to the increase of the cross-link density. These results indicated that the TCNP may be enclosed or trapped in the occluded structure of CB. The effect of CB and TCNP content on the tensile strength (σ), elongation at break (εb %) and modulus of elasticity (E, MPa) of natural rubber/ butyl rubber NR/IIR blend have been investigated. The incorporation of 5 phr of TCNP into 30 phr carbon black loaded NR/ IIR composites results in the increased tensile strength value by about 60%. Finally, theoretical models were used to interpret the experimental results.

Crosslinking and Mechanical Properties of Liquid Rubber. I. Curative Effect of Aliphatic DIOLS

1979 ◽  
Vol 52 (5) ◽  
pp. 920-948 ◽  
Author(s):  
Yuji Minoura ◽  
Shinzo Yamashita ◽  
Hiroshi Okamoto ◽  
Tadao Matsuo ◽  
Michiaki Izawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Low Molecular Weight ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Curative Effect ◽  
Polyurethane Elastomers ◽  
X Ray ◽  
Structure Property Relationships ◽  
The Difference

Abstract The structure-property relationships of polyurethane elastomers derived from a liquid hydroxyl-terminated polybutadiene/low molecular weight aliphatic diol/diisocyanate system were studied. The effects of the amount of low molecular weight diol on the mechanical properties of the elastomer were discussed on the basis of the results of stress-strain, swelling, dynamic viscoelasticity, x-ray diffraction, etc. It was found that some particular combinations of low molecular weight diol and diisocyanate specifically affect the properties of elastomers. When the mechanical properties of the elastomers were plotted against the number of methylene carbons in the low molecular weight diol, characteristic zigzag patterns were obtained. These patterns were explained by the difference in the packing and the dependence of the strength of intermolecular hydrogen bonding on whether the number of the methylene carbons was even or odd. This assumption was confirmed by x-ray diffraction.

scholarly journals Enhancing thermal and mechanical properties of polypropylene using masterbatches of nanoclay and nano-CaCO3: A review

2018 ◽  
Vol 3 (1) ◽  
pp. 19-26
Author(s):  
Achmad Chafidz
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Nanocomposites ◽  
Review Paper ◽  
Thermal And Mechanical Properties ◽  
Structure Property ◽  
Melt Compounding ◽  
Structure Property Relationships ◽  
Composites Materials ◽  
Macro Scale

Polymer nanocomposites (PNCs) can be considered as promising relatively new types of composite materials. PNCs give opportunity to develop new composites materials with different structure-property relationships compared to their conventional micro/macro scale composites. Polyolefin based nanocomposites nowadays become more important, because this type of composites has been largely used in various industries. For example, polypropylene based nanocomposites have been widely used in automobile – related industries to replace their conventional composites. This review paper will focus on the polypropylene based nanocomposites prepared using masterbatches of nanoclay and nano-CaCO3 via melt compounding method. The thermal and mechanical properties of such nanocomposites were also discussed.

Structure/Property Relationships and Applications of Rapidly Solidified Aluminum Alloys

1981 ◽  
Vol 8 ◽  
Author(s):  
C. M. Adam
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Aluminum Alloys ◽  
Thermomechanical Processing ◽  
Structure Property ◽  
Turbine Engine ◽  
Structure Property Relationships ◽  
Plant Stage ◽  
Spherical Droplets ◽  
Rapidly Solidified

ABSTRACTDuring the last five years Pratt & Whitney Aircraft has developed rapid solidification powder metallurgy and consolidation techniques to produce advanced aluminum alloys. A centrifugal rotary atomization device with forced high velocity helium convective cooling has been developed to pilot-plant stage, to produce aluminum alloys of novel compositions for advanced gas turbine engine applications. Rapidly solidified aluminum alloys solidify as spherical droplets up to 100 μm diameter with cooling rates of 105 — 106 K/sec, and demonstrate new microstructural features which have been exploited to develop elevated temperature mechanical properties. Alloys have been developed for 400 — 500°F fan and compressor applications that have traditionally used titanium alloys, and this paper reviews the microstructural evolution of rapidly solidified structures during thermomechanical processing.

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