scholarly journals TPV: A New Insight on the Rubber Morphology and Mechanic/Elastic Properties

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2315
Author(s):  
Cindy Le Hel ◽  
Véronique Bounor-Legaré ◽  
Mathilde Catherin ◽  
Antoine Lucas ◽  
Anthony Thèvenon ◽  
...  
Keyword(s):  
Carbon Black ◽  
Crosslinking Agent ◽  
Domain Size ◽  
Organic Peroxide ◽  
Packing Fraction ◽  
Crosslinking Reaction ◽  
High Concentration ◽  
Compression Set ◽  
Thermoplastic Matrix ◽  
Rubber Phase

The objective of this work is to study the influence of the ratio between the elastomer (EPDM) phase and the thermoplastic phase (PP) in thermoplastic vulcanizates (TPVs) as well as the associated morphology of the compression set of the material. First, from a study of the literature, it is concluded that the rubber phase must be dispersed with a large distribution of the domain size in the thermoplastic phase in order to achieve a high concentration, i.e., a maximal packing fraction close to ~0.80. From this discussion, it is inferred that a certain degree of progress in the crosslinking reaction must be reached when the thermoplastic phase is melted during mixing in order to achieve dispersion of the elastomeric phase in the thermoplastic matrix under maximum stress. In terms of elasticity recovery which is measured from the compression set experiment, it is observed that the crosslinking agent nature (DCP or phenolic resin) has no influence in the case of a TPV compared with a pure crosslinked EPDM system. Then, the TPV morphology and the rubber phase concentration are the first order parameters in the compression set of TPVs. Finally, the addition of carbon black fillers leads to an improvement of the mechanical properties at break for the low PP concentration (20%). However, the localization of carbon black depends on the crosslinking chemistry nature. With radical chemistry by organic peroxide decomposition, carbon black is located at the interface of EPDM and PP acting as a compatibilizer.

Compressive Deformation and Energy Absorption Characteristics of Conductive Carbon Black Reinforced Microcellular EPDM Vulcanizates

2005 ◽  
Vol 24 (4) ◽  
pp. 209-222 ◽  
Author(s):  
S.P. Mahapatra ◽  
D.K. Tripathy
Keyword(s):  
Carbon Black ◽  
Compressive Stress ◽  
Energy Absorption ◽  
Filler Loading ◽  
Maximum Efficiency ◽  
Stress Strain ◽  
Blowing Agent ◽  
Compression Set ◽  
Rate Dependent ◽  
Conductive Carbon Black

Compressive stress-strain properties of unfilled and conductive carbon black (VulcanXC 72) filled oil extended EPDM (keltan 7341A) microcellular vulcanizates were studied as a function of blowing agent (density) and filler loading. With decrease in density, the compressive stress-strain curves for microcellular vulcanizates behaved differently from those of solid vulcanizates. The compressive stress-strain properties were found to be strain rate dependent. The log-log plots of relative density of the microcellular vulcanizates showed a fairly linear correlation with the relative modulus. The compression set at a constant stress increased with decrease in density. The efficiency of energy absorption E, was also studied as a function of filler and blowing agent loading. From the compressive stress-strain plots the efficiency E and the ideality parameter I, were evaluated. These parameters were plotted against stress to obtain maximum efficiency and the maximum ideality region, which will make these materials suitable for cushioning and packaging applications in electronic devices.

Effect of carbon black loading on the swelling and compression set behavior of SBR and NBR rubber compounds

2009 ◽  
Vol 30 (5) ◽  
pp. 1561-1568 ◽  
Author(s):  
A. Mostafa ◽  
A. Abouel-Kasem ◽  
M.R. Bayoumi ◽  
M.G. El-Sebaie
Keyword(s):  
Carbon Black ◽  
Compression Set ◽  
Rubber Compounds

Fluoroelastomer Applications for Pollution Control in the Automotive, Petrochemical, and Electric Power Industries

1982 ◽  
Vol 55 (4) ◽  
pp. 1137-1151 ◽  
Author(s):  
R. R. Campbell ◽  
D. A. Stivers ◽  
R. E. Kolb
Keyword(s):  
Tensile Strength ◽  
Sulfuric Acid ◽  
Carbon Black ◽  
Pollution Control ◽  
Acid Resistance ◽  
Organic Peroxide ◽  
Exposed Surface ◽  
Chemical Attack ◽  
Temperature Ranges ◽  
Concentrated Sulfuric Acid

Abstract The effects of percent fluorine, filler, and cure systems on the thermal and acid resistance of fluoroelastomers were evaluated over temperature ranges that would be typical of actual flue duct installations and accelerated conditions such as 275°C for thermal resistance and 149°C for concentrated sulfuric acid resistance. FKM 2176, which contains 65% fluorine by weight, became hard and brittle after two weeks of accelerated air aging at 275°C. The balance of physical properties of FKM 2176 were good when aged at 200°C. FKM 4894, which contains 67% fluorine by weight, retained useful properties after six weeks of accelerated air aging at 275°C. This indicates this material has improved properties for flue duct applications compared to FKM 2176. FKM 4894 filled with MT carbon black had improved retention of tensile strength after aging at 232°C relative to the FKM 4894 filled with SRF/HAF black, Austin Black and litharge. FKM 2176 was totally degraded after aging three days at 149°C in concentrated sulfuric acid. Aging of FKM 4894 in concentrated sulfuric acid at 149°C resulted in a loss of approximately 75 percent of the original tensile and an increase in the elongation, and the appearance of the exposed surface did not indicate chemical attack. Although FKM 4894 was superior to FKM 2176 when aged in sulfuric acid at 149°C, there was little difference between FKM 4894 and FKM 2176 when aged at 121 °C for up to four weeks or after eight weeks at 100°C in concentrated sulfuric acid. Austin Black showed the best retention of tensile of the four filler systems evaluated after aging at 100°C in concentrated sulfuric acid. FKM 4826, which contains 69% fluorine and is vulcanized using organic peroxide and triallyl isocyanurate, has indicated a compatibility with fiberglass that is superior to all fluorocarbon elastomer gums that were tested.

Structure-Property Relationships of N,N′-Dinitroso-P-Phenylene-Bis (Hydroxylamine) Salts. Vulcanization of Nonhalogenated Elastomers

1962 ◽  
Vol 35 (1) ◽  
pp. 141-146 ◽  
Author(s):  
Rock F. Martel ◽  
David E. Smith
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Silver Salt ◽  
Crosslinking Agent ◽  
Authentic Sample ◽  
Zinc Powder ◽  
Metallic Silver ◽  
Crosslinking Reaction ◽  
Oxides Of Nitrogen ◽  
Structure Property

Abstract In a previous report the vulcanization activity of N,N′-dinitroso-p-phenylene-bis(hydroxylamine) salts in Neoprene WRT was discussed. The vulcanization was catalyzed by addition of stoichiometric amounts of aluminum or zinc powder (based upon percentage of allylic chloride), very possibly via the metal halide formed in situ. Natural rubber could not be vulcanized with these materials, however, differential thermal analysis indicated that amine-treated neoprene undergoes a crosslinking reaction at above normal curing temperatures. This evidence led us to propose that bisalkylation (α and/or β) at the allylic position is responsible for the formation of crosslinks. The mechanistic path is shown in Equations 1 and 2, and the analogy with the SN2′ activity of diamines in neoprene is quite apparent. The crosslinks III and/or IV are shown as the β form and one of the possible a structures. A number of structures for the α form have been proposed. The β structure has been known for some time. Our primary interest at this point was to extend the activity of N,N′-dinitroso-p-phenylene-bis(hydroxylamine) salts to elastomers which do not contain halogen. Any hope of achieving this goal depended, for the most part, upon whether or not certain of these materials would produce p-dinitrosobenzene, a known crosslinking agent, during the vulcanization cycle. The silver salt of phenylnitrosohydroxylamine, the monosubstituted counterpart of the bis(hydroxylamine) structure, decomposes readily to nitrosobenzene, nitric oxide and metallic silver. Accordingly, we prepared the di-silver salt of N,N′-dinitroso-p-phenylene-bis(hydroxylamine). The maximum rate of decomposition of this material was determined by differential thermal analysis, and occurred at 295° F. When 1.0 g of the di-silver salt was heated [see Reaction (3)] at 200° F for 2 hours, 0.3 g of a yellow solid sublimate was collected on a cold finger. The infrared spectrum of the yellow solid was identical with that of an authentic sample of p-dinitrosobenzene. Oxides of nitrogen were also visible in the reaction vapors (brown coloration).

scholarly journals Graphene Oxide and Oxidized Carbon Black as Catalyst for Crosslinking of Phenolic Resins

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1330 ◽  
Author(s):  
Maria Rosaria Acocella ◽  
Aniello Vittore ◽  
Mario Maggio ◽  
Gaetano Guerra ◽  
Luca Giannini ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Thermal Treatment ◽  
Carbon Black ◽  
Crosslinking Reaction ◽  
Scanning Calorimetry ◽  
Indirect Methods ◽  
Phenolic Resins ◽  
Oxidized Carbon

Influence of different graphite-based nanofillers on crosslinking reaction of resorcinol, as induced by hexa(methoxymethyl)melamine, is studied. Curing reactions leading from low molecular mass compounds to crosslinked insoluble networks are studied by indirect methods based on Differential Scanning Calorimetry. Reported results show a catalytic activity of graphene oxide (eGO) on this reaction, comparable to that one already described in the literature for curing of benzoxazine. For instance, for an eGO content of 2 wt %, the exothermic crosslinking DSC peak (upon heating at 10 °C/min) shifted 6 °C. More relevantly, oxidized carbon black (oCB) is much more effective as catalyst of the considered curing reaction. In fact, for an oCB content of 2 wt %, the crosslinking DSC peak can be shifted more than 30 °C and a nearly complete crosslinking is already achieved by thermal treatment at 120 °C. The possible origin of the higher catalytic activity of oCB with respect to eGO is discussed.

Kinetics of Peroxide Vulcanization of Natural Rubber

2012 ◽  
Vol 28 (4) ◽  
pp. 201-220 ◽  
Author(s):  
Rejitha Rajan ◽  
Siby Varghese ◽  
K.E. George
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Crosslinking Agent ◽  
Decomposition Reaction ◽  
Dominant Factor ◽  
Compression Set ◽  
Cure Time ◽  
Minimum Residual ◽  
Vulcanization Kinetics ◽  
Kinetics Of

This study was undertaken to optimize the vulcanization conditions and explore the effect of residual peroxide in the peroxide vulcanization of natural rubber. The study was followed through the kinetics of the vulcanization reaction at various temperatures viz. 150,155,160 and 165°C. Dicumyl peroxide (DCP) was used as the crosslinking agent. The Monsanto Rheometer was used to investigate the different crosslinking stages and vulcanization kinetics. The thermal decomposition of peroxide followed a first order free radical decomposition reaction. Half-lives at various temperatures were determined. The percentage of residual peroxide was calculated from the cure kinetic data. The effect of residual peroxide on mechanical properties was studied at various peroxide levels and also by extending the cure time (from t90 to t95 and then to t100). Mechanical properties such as tensile strength, elongation at break, modulus and compression set (70 and 100°C) were measured. Excess peroxide was found to cause a high compression set at elevated temperature and the cure time was selected to achieve minimum residual peroxide in the product. Results indicate that peroxide concentration is the dominant factor controlling the crosslink density and hence the properties of the vulcanizates.

Mechanism of Peroxide Vulcanization of Elastomers

1967 ◽  
Vol 40 (1) ◽  
pp. 149-176 ◽  
Author(s):  
L. D. Loan
Keyword(s):  
Crosslinking Agent ◽  
Basic Mechanism ◽  
Organic Peroxide ◽  
Detailed Examination ◽  
Recent Book ◽  
Operational Conditions ◽  
The Subject ◽  
Curing Agents ◽  
The Common ◽  
Technological Evaluation

Abstract As is now well known, the use of an organic peroxide as a crosslinking agent for an elastomer was first reported by Ostromislensky in 1915. In this work benzoyl peroxide was used to cure natural rubber; similar acyl peroxides together with more recently discovered, less active, and more convenient dialkyl peroxides have since this time been used to crosslink a very large number of polymers. With the common unsaturated polymers the vulcanizates produced have mechanical properties rather inferior to those obtained with accelerated sulfur cures. They do, however, have the good aging and low compression set properties which are, in general, associated with sulfurless cures. The commercial use of peroxides in unsaturated elastomers is nevertheless small, being employed only where the presence of sulfur would be deleterious. In spite of its technological disadvantages peroxide crosslinking has been extensively studied since it forms a chemically simple means of introducing crosslinks into a wide variety of rubbers and leads to vulcanizates of simple structure with physically and chemically stable, carbon-to-carbon crosslinks. Interest in the industrial use of peroxides as curing agents has increased recently with the introduction of a number of fully saturated rubbers for which the usual accelerated sulfur systems are unsuitable. Such saturated rubbers are, in general, more resistant to aging, are more thermally stable, and will probably be used to increasingly greater extents as operational conditions become more and more severe. The study of curing systems available for use with such rubbers is therefore of considerable importance and organic peroxides, forming one such system, are worthy of detailed examination. Much work has been done on the technological evaluation of peroxide vulcanizates and much of this is summarized in a recent book edited by Alliger and Sjothun which is recommended as a source of references for a more detailed study of this aspect of the subject. The basic mechanism of the peroxide crosslinking of a wide variety of rubbers has, however, been neglected until relatively recently. For this reason, and for reasons of length, it is proposed to limit the present review to this latter aspect of the subject.

Effect of Methyl Methacrylate Content in Carbon Black Filled Natural Rubber Compounds

2012 ◽  
Vol 501 ◽  
pp. 3-7
Author(s):  
Abu Bakar Rohani ◽  
Mustafa Kamal Mazlina ◽  
Fauzi Mohd Som
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Proton Nuclear Magnetic Resonance ◽  
Performance Parameters ◽  
Rubber Content ◽  
Elongation At Break ◽  
Compression Set ◽  
Rubber Compounds ◽  
Emulsion Polymerisation

Natural rubber-grafted-poly(methyl methacrylate) containing 30 and 50 percent of methyl methacrylate (MMA) monomer per 100 parts by weight of the dry rubber content denoted as NR-g-PMMA 30 and NR-g-PMMA 50, respectively were prepared via emulsion polymerisation technique. The occurrences of graft copolymerisation of PMMA onto NR were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) following purifications. The reinforcement of rubber by fillers is of great practical and technical importance. Thus, these fillers are added to rubber formulations to optimize the properties to meet a given application or set of performance parameters. In this study, the effect of carbon black in NR-g-PMMA 30 and NR-g-PMMA 50 rubber compounds were evaluated. Our results demonstrated that tensile strength, elongation at break and compression set reduced, while the hardness and solvent resistance increased in the presence of carbon black filler in comparison to the unfilled compound.

Morphology Evolution and Mechanical Properties of HNBR Composites Reinforced by HZMMA/Carbon Black during Curing Process

2015 ◽  
Vol 740 ◽  
pp. 23-27 ◽  
Author(s):  
Guan Zhong Wang ◽  
Zeng Lin Wang ◽  
Shuai Cheng Tian ◽  
Shou Peng Wu ◽  
Fu Tao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Early Stage ◽  
Continuous Phase ◽  
Partial Substitution ◽  
Crosslinking Reaction ◽  
Curing Process ◽  
Rubber Composites ◽  
Elongation At Break ◽  
Vulcanization Process

Hydroxyl zinc mono-methacrylate/carbon black/hydrogenated nitrile rubber composites were prepared by using HZMMA as a partial substitution for carbon black. The morphology and properties of the composites during the vulcanization process were investigated. The results showed that during early stage of the curing process, the tensile strength and modulus at 100% of the composites increased slightly, the tear strength and elongation at break decreased. The favorable mechanical properties for composites could be achieved after post-curing. FTIR, XRD, and TEM results showed that the polymerization of HZMMA completes at the beginning stage of curing process. Grafting and crosslinking reaction between HZMMA and HNBR may occur during the curing process and metallic bridge bond between them forms. The phase state of homopolymer transformed from disperse phase to continuous phase and has a good compatibility with HNBR.

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