Effect of Polymer-Filler and Filler-Filler Interactions on Dynamic Properties of Filled Vulcanizates

1998 ◽  
Vol 71 (3) ◽  
pp. 520-589 ◽  
Author(s):  
Meng-Jiao Wang
Keyword(s):  
Molecular Weight ◽  
Network Formation ◽  
Dynamic Properties ◽  
Monomer Unit ◽  
Polymer Network ◽  
General Rule ◽  
Filled Rubber ◽  
Polymer Filler ◽  
Filler Network ◽  
Main Components

Abstract In the past few years, an enormous amount of work has been reported on the progress in the application of conventional fillers and the development of new products to improve the reinforcement of rubber, dynamic properties in particular. While all agree that the filler as one of the main components of the filled-rubber composite, has a very important role in improving the dynamic performances of the rubber products; many new ideas, theories, practices, phenomena, and observations about how and especially why the filler alters the dynamic stress-strain response have been presented. This, of course, suggests that not only is the real world of the filled rubber complex and sophisticated but also multiple mechanisms may be involved. However, it must be admitted that the possibility exists for explaining the effect of all fillers on rubber properties ultimately in similar and relatively nonspecific terms, i.e., the phenomenon related to all filler parameters should follow a general rule or principle. It is the author's belief that, with regard to the effect of filler on the dynamic properties of a given polymer and cure system, filler networking, both its architecture and strength, is the main (although not only) parameter to govern the behavior of the filled rubber. From the thermodynamic and kinetic points of view, filler network formation is especially related to filler-filler, polymer-filler, as well as polymer-polymer interactions. As mentioned in the introduction, this paper is an attempt to review the effect of filler characteristics on dynamic properties in connection with processing conditions and additives. Since the polymer-filler interaction is not only affected by filler, what is also important are the characteristics of polymers such as chemical composition, chain microstructure including molecular weight and molecular weight distribution, configuration, stereoregularity, monomer unit distribution and sequence, and their functionality. All of these have a substantial influence on the physical and/or chemical interactions with other additives and filler surfaces, as well as on the interaction between polymer molecules themselves, which would impact not only the filler network formation but also the viscoelastic response of the polymer matrix. In addition, the polymer network structure which was formed during vulcanization and characterized by crosslink density, crosslink structure, and chain modification, is equally important in contributing to the overall dynamic properties of the filled rubber. In this paper, only some of these aspects have been discussed relative to their effect on filler network formation. Further discussion of these parameters is beyond the subject of the present paper. However, some guidance to these important topics is given in a handbook that was recently published.

The Role of Filler Networking in Dynamic Properties of Filled Rubber

1999 ◽  
Vol 72 (2) ◽  
pp. 430-448 ◽  
Author(s):  
Meng-Jiao Wang
Keyword(s):  
Dynamic Properties ◽  
Cyclic Strain ◽  
Considerable Change ◽  
Dynamic Strain ◽  
Additional Energy ◽  
Polymer Systems ◽  
Filled Rubber ◽  
Filler Network ◽  
The Impact

Abstract Fillers, when added to polymer systems, are known to cause a considerable change in dynamic properties. For a given polymer and cure system, this paper discusses the impact of the filler network, both its strength and architecture, on the dynamic modulus and hysteresis during dynamic strain. It was found that the filler network can substantially increase the effective volume of the filler due to rubber trapped in the agglomerates, leading to high elastic modulus. The amount of trapped rubber was estimated according to Van der Poel theory. During cyclic strain, while the stable filler network can reduce the hysteresis of the filled rubber, the breakdown and reformation of the filler network would cause an additional energy dissipation resulting in higher hysteresis.

Influence of Different Silanes on the Reinforcement of Silica-Filled Rubber Compounds

2002 ◽  
Vol 75 (4) ◽  
pp. 563-579 ◽  
Author(s):  
Hans-Detlef Luginsland ◽  
Joachim Fröhlich ◽  
André Wehmeier
Keyword(s):  
Alkyl Chain ◽  
Dynamic Properties ◽  
General Effect ◽  
Silica Network ◽  
Precipitated Silica ◽  
Filled Rubber ◽  
Rubber Compounds ◽  
Silane Modification ◽  
Filler Network ◽  
Insight Into

Abstract The silane modification of precipitated silica for rubber applications is state-of-the-art. Usually, bifunctional silanes are used to provide a silica-to-rubber coupling. In this paper, the general effect of the silane modification on the Payne-effect of silica-filled compounds (S-SBR/BR) is investigated by applying the Rubber Process Analyzer (RPA). For this purpose, the amount as well as the type of silane have been varied. The alkyl chain length of monofunctional silanes determines their hydrophobation efficiency and therefore influences the degree of the silica network, whereas bifunctional silanes also contribute to the crosslinking and build up an in-rubber structure. The degree of the filler network is not only determined by the kind of silica modification, but also by the reinforcement behavior of the silica, mainly characterized by the CTAB surface area. The findings of this study give a better insight into the reinforcement of silica-filled rubber compounds and their dynamic properties.

Adsorption of monodisperse polybutadienes on carbon black, 2 Bulk adsorption

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Kathy Vuillaume ◽  
Bassel Haidar ◽  
Alain Vidal
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Conformational Transition ◽  
Adsorbed Molecules ◽  
Molecular Weights ◽  
Polymer Filler ◽  
Filler Network

Abstract The adsorption on carbon black (CB) of a series of monodisperse polybutadienes (PBs) with different molecular weights (Mn in the range of 3000 to 120 000) but identical microstructure (1,2-PB content ≈ 80%) was studied in the bulk for different polymer/CB ratios (τ, in the range of 2 to 10 g/g). In this respect we particularly studied the evolution of the amount of polymer, which cannot be extracted from the polymer/filler system upon blending, the so-called bound polymer, and attempted to investigate the conformation of the resulting adsorbed molecules as well as the conditions that control the formation of the polymer/filler network. The conformational transition turned out to depend exclusively on molecular weight, and the networking transition to occur at constant Mn1/2/τ, essentially through an entanglement process of the adsorbed chains.

scholarly journals Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

2012 ◽  
Vol 26 (3) ◽  
pp. 249-255
Author(s):  
Boniek Castillo Dutra Borges ◽  
Fabrício Lopes da Rocha Pereira ◽  
Roberta Caroline Bruschi Alonso ◽  
Rodivan Braz ◽  
Marcos Antônio Japiassú Resende Montes ◽  
...  
Keyword(s):  
Network Formation ◽  
Polymer Network

Viscoelastic Relaxation of Rubber Vulcanizates Between the Glass Transition and Equilibrium

1966 ◽  
Vol 39 (4) ◽  
pp. 870-880 ◽  
Author(s):  
R. Chasset ◽  
P. Thirion
Keyword(s):  
Molecular Weight ◽  
Dynamic Properties ◽  
Average Length ◽  
Linear Part ◽  
Polymer Networks ◽  
Relaxation Times ◽  
Distribution Functions ◽  
Viscoelastic Relaxation ◽  
Theoretical Understanding ◽  
Rouse Theory

Abstract In agreement with the results of dynamic experiments of Stratton and Ferry, this study of relaxation of rubber vulcanizates entirely confirms the existence of peculiar, slow, viscoelastic processes in high polymer networks. Characteristic differences with the rheological behavior of unvulcanized polymers are best reflected by the shape of the end of the distribution functions of relaxation times. The box distribution found for free chains is replaced, for crosslinked polymers, by a long incline extending during several decades of time. The slope of this linear part of the spectrum is only slightly dependent on nature of the polymer and type of vulcanizate. On the other hand, the position of the incline along the time scale is very sensitive to the mean molecular weight Mc of the vulcanizates, by far the most important factor controlling the phenomenon. The downward deviations observed at the end of the incline also occur later for larger values of Mc. A useful step towards theoretical understanding of this behavior should be a quantitative knowledge of the effect of molecular weight in a broader range of Mc than studied here. If the chain entanglements are of primary importance, as considered probable by Ferry it seems that some singularity should occur for a critical molecular weight fitting the corresponding value for the viscosity of free chains. The role of crosslink mobility might be tested by comparing the relaxation of ordinary random vulcanizates with that of eventually more regular polybutadiene networks prepared by end group crosslinking of carboxy-terminated and mono-disperse chains. In fact, the displacement of a crosslink away from its affine position requires, apart from the Brownian fluctuations, an unbalance between the forces exerted by the four radiating chains. This implies that the lengths of the strands present large differences and that the shortest chains are approaching their limit of extensibility. As the latter condition can hardly be fullfilled at small deformations, it seems doubtful that this mechanism may be predominant either for dynamic properties or the relaxation experiments reported here. Another cause sometimes invoked is the presence of free chains attached to the networks and we are presently studying their effect on viscoelastic relaxation. At this stage, it is already apparent that they do not have a large effect, as might be expected on theoretical grounds. In our opinion, special attention should be paid to the reason why the experimentally found relaxation times are so large, in spite of the relatively short average length of the network strands. If the usual notion of entanglements developed for free chains, as an extension of the Rouse theory, should fail in this respect, it would be necessary to reconsider the non-equilibrium statistics of single chains with fixed ends, taking into account the proper inter- and intramolecular forces hindering their motion. This more direct approach to the problem, already outlined by Kirkwood, ought to express mathematically the fact that the presence of crosslinks tends to prevent longitudinal slippage of large parts of the chains. The slow changes of configuration should occur therefore rather through lateral motions to which the neighboring medium opposes a much greater resistance.

THERMOPHYSICAL AND DYNAMIC PROPERTIES OF BUTADIENE-NITRILE RUBBER FILLED WITH ULTRA HIGH-MOLECULAR WEIGHT POLYETHYLENE

2021 ◽  
Vol 0 (2) ◽  
pp. 36-43
Author(s):  
N.V. Shadrinov ◽  
◽  
A.A. Khristoforova ◽  
Keyword(s):  
Molecular Weight ◽  
Dynamic Properties ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Physicomechanical Properties ◽  
Butadiene Rubber ◽  
Rubber Compounds ◽  
Ultrahigh Molecular Weight ◽  
Before And After ◽  
Butadiene Nitrile Rubber ◽  
Ultra High Molecular Weight

The results of the study of the complex of properties of an elastomeric composite material based on nitrile butadiene rubber BNKS-18 and ultrahigh molecular weight polyethylene are presented. The effect of UHMWPE on the vulcanization characteristics of rubber compounds, the physicomechanical properties of vulcanizates before and after thermal aging in a hydrocarbon environment and air, and also on the dynamic properties before and after curing are investigated.

scholarly journals Separation, purification and properties of β-lactamase I and β-lactamase II from Bacillus cereus 569/H/9

1974 ◽  
Vol 143 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Richard B. Davies ◽  
E. P. Abraham ◽  
J. Melling
Keyword(s):  
Molecular Weight ◽  
Bacillus Cereus ◽  
Large Scale ◽  
Cysteine Residue ◽  
Peptide Fragment ◽  
Tryptic Digest ◽  
Purification And Properties ◽  
Carbohydrate Complex ◽  
Entire Sequence ◽  
Main Components

1. A procedure was devised which is suitable for the isolation of β-lactamase I and β-lactamase II from Bacillus cereus 569/H/9 on a large scale. After adsorption on to Celite both enzymes were eluted in good yield and separated by chromatography on Sephadex CM-50. 2. β-Lactamase I was separated into three main components by isoelectric focusing and into two components by chromatography. 3. The Zn2+-requiring β-lactamase II obtained by this procedure had a lower molecular weight (22000) than β-lactamase I (28000) and also differed from the latter in containing one cysteine residue. 4. The β-lactamase II contained no carbohydrate, but showed the thermostability of the enzyme isolated earlier as a protein–carbohydrate complex. 5. Amino acid analyses and tryptic-digest ‘maps’ indicate that some degree of homology between β-lactamase I and β-lactamase II is possible, but that β-lactamase I is not composed of the entire sequence of β-lactamase II together with an additional peptide fragment. 6. A 6-methylpenicillin and a 7-methylcephalosporin showed much lower affinities for both enzymes than did penicillins and cephalosporins themselves.

Dynamic Properties of Engine Main Components

2012 ◽  
Vol 455-456 ◽  
pp. 1454-1458
Author(s):  
Wen Bing Yan ◽  
Hong Xia Pan ◽  
Shao Zhong Jiang
Keyword(s):  
Dynamic Properties ◽  
Main Components

scholarly journals Coupling the Microscopic Healing Behaviour of Coatings to the Thermoreversible Diels-Alder Network Formation

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Joost Brancart ◽  
Robrecht Verhelle ◽  
Jessica Mangialetto ◽  
Guy Van Assche
Keyword(s):  
Network Formation ◽  
Polymer Network ◽  
Cycloaddition Reaction ◽  
Thermomechanical Properties ◽  
Alder Reaction ◽  
Diels Alder ◽  
Force Microscopy ◽  
Diels Alder Reaction ◽  
Atomic Force ◽  
Microscopic Evaluation

While thermally reversible polymer network coatings based on the Diels-Alder reaction are widely studied, the mechanisms responsible for the heating-mediated healing of damage is still not well understood. The combination of microscopic evaluation techniques and fundamental insights for the thermoreversible network formation in the bulk and coating shed light on the mechanisms behind the damage healing events. The thermomechanical properties of thermoset and elastomer coatings, crosslinked by the furan-maleimide Diels-Alder cycloaddition reaction, were studied in bulk and compared to the thermal behaviour applied as coatings onto aluminium substrates. The damage sealing of thermoset (Tg = 79 °C) and elastomer (Tg = −49 °C) coatings were studied using nano-lithography and atomic force microscopy (AFM). The sealing event is studied and modelled at multiple temperatures and correlated to the changes in the network structure and corresponding thermomechanical properties.

scholarly journals Polymer gel with a flexible and highly ordered three-dimensional network synthesized via bond percolation

2019 ◽  
Vol 5 (12) ◽  
pp. eaax8647 ◽  
Author(s):  
X. Li ◽  
S. Nakagawa ◽  
Y. Tsuji ◽  
N. Watanabe ◽  
M. Shibayama
Keyword(s):  
Network Formation ◽  
General Scheme ◽  
Polymer Network ◽  
Three Dimensional ◽  
Geometric Constraints ◽  
Polymer Chains ◽  
Bond Percolation ◽  
Polymer Gel ◽  
Temporal Correlations ◽  
Before And After

Gels are a soft elastic material consisting of a three-dimensional polymer network with nanometer-sized pores and are used in a variety of applications. However, gel networks typically have a substantial level of defects because the network formation reaction proceeds stochastically. In this study, we present a general scheme to fabricate gels with extremely low levels of defects by applying geometric constraints into pregel solution based on the “bond percolation” concept. In the formed gel, stationary laser speckles, which are an indicator of spatial defects, were not observed at all. In addition, we found that the concentration fluctuations of the polymer chains were ergodic across the whole gel network. In such a homogeneous gel, both the spatial and temporal correlations of polymer chains are the same before and after gelation.

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