Studies on reinforcing effect of industrial nano silica in chloroprene vulcanizates containing carboxy-terminated liquid natural rubber

2021 ◽  
pp. 009524432110635
Author(s):  
Gopika Sudhakaran ◽  
Shanti A Avirah
Keyword(s):  
Maleic Anhydride ◽  
Natural Rubber ◽  
Cost Effective ◽  
Cross Linking ◽  
Nano Silica ◽  
Rubber Content ◽  
Reinforcing Effect ◽  
Bound Rubber ◽  
Liquid Natural Rubber ◽  
Rubber Filler

Maleic anhydride was chemically attached to depolymerized natural rubber, and the product was named as carboxy-terminated liquid natural rubber (CTNR). The CTNR can act as a potential plasticizer in chloroprene (CR) vulcanizates. This paper describes the use of commercial nano silica (NS) as a promising cost-effective filler, which can enhance the tensile properties and ageing resistance of the CR vulcanizates incorporated with CTNR (CR-CTNR). The enhancement in properties may be attributed to the increased bound-rubber content owing to the large surface area of the nano-sized filler. The characteristics of the NS-filled CR vulcanizates containing CTNR (NS CR-CTNR) were compared with those containing amorphous silica. The NS CR-CTNR vulcanizates showed superior ageing and oil resistance due to the finer rubber filler interaction modified by ionic cross linking.

Improvement of Filler-Rubber Interaction by Grafting of Acrylamide onto Saponified Natural Rubber under Ultraviolet Radiation as a Continuous Process

2015 ◽  
Vol 659 ◽  
pp. 414-417 ◽  
Author(s):  
Nattanee Dechnarong ◽  
Adun Nimpaiboon ◽  
Jitladda Sakdapipanich
Keyword(s):  
Natural Rubber ◽  
Uv Radiation ◽  
Continuous Process ◽  
Rubber Compound ◽  
Rubber Content ◽  
Filled Rubber ◽  
Reinforcing Fillers ◽  
Bound Rubber ◽  
Mooney Viscosity ◽  
Rubber Filler

Silica and carbon black have been widely used as the main reinforcing fillers for improving the properties of natural rubber (NR). In a silica-filled rubber compound, it is known that the low compatibility between NR and silica affects the mechanical properties of rubber products. In order to overcome this drawback, the functionalized saponified NR (FSPNR) was carried out by grafting acrylamide (AM) onto the saponified NR (SPNR) under UV radiation as a continuous process. An increasing in the bound rubber content and Mooney viscosity was found as an increasing AM content. Storage modulus at low strain amplitude of the silica-filled FSPNR was lower than that of the raw NR. In addition, SEM micrographs showed the good dispersion of silica in FSPNR. These confirmatory evidences indicate the improvement of rubber-filler interaction and the reduction of filler-filler interaction by functionalization under UV radiation.

EFFECTS OF SILANE COUPLING AGENTS ON STRUCTURE AND PROPERTIES OF SILICA-FILLED SILICONE RUBBER/STYRENE BUTADIENE RUBBER COMPOSITES

2018 ◽  
Vol 91 (2) ◽  
pp. 453-468 ◽  
Author(s):  
Hong-Yuan Ren ◽  
Zheng Sun ◽  
Li-Qun Zhang ◽  
You-Ping Wu ◽  
Qiang Huang ◽  
...  
Keyword(s):  
Styrene Butadiene Rubber ◽  
Coupling Agents ◽  
Butadiene Rubber ◽  
Structure And Properties ◽  
Silane Coupling Agents ◽  
Rubber Content ◽  
Bound Rubber ◽  
Silane Coupling ◽  
Styrene Butadiene ◽  
Rubber Filler

ABSTRACT Two silane coupling agents, bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si69) and vinyltriethoxysilane (A151), were selected to investigate their effects on structure and properties of silica-filled methyl vinyl silicone rubber (VMQ)/emulsion styrene butadiene rubber (ESBR) composites. The filler–rubber interactions were investigated via bound rubber content and solid-state 1H low-field nuclear magnetic resonance (NMR) spectroscopy, and the mass ratio of VMQ and ESBR in the rubber–filler gel was investigated by thermogravimetric analysis (TGA). The results revealed that VMQ showed a better compatibility with silica than ESBR. Compared with the A151 composite, the composite with Si69 showed the higher content of ESBR in rubber–filler gel, which resulted in the higher bound rubber content and the weaker Payne effect, and it also exhibited higher tensile strength, higher tear strength, better wear resistance, and lower hardness. However, the presence of Si69 reduced the crosslink efficiency of ESBR and completely inhibited the crosslinking of VMQ, which caused the composite to show higher tan δ value at 60 °C than the A151 composite.

REINFORCEMENT OF NATURAL RUBBER BY SILICA/SILANE IN DEPENDENCE OF DIFFERENT AMINE TYPES

2017 ◽  
Vol 90 (4) ◽  
pp. 651-666 ◽  
Author(s):  
C. Hayichelaeh ◽  
L. A. E. M. Reuvekamp ◽  
W. K. Dierkes ◽  
A. Blume ◽  
J. W. M. Noordermeer ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Natural Rubber ◽  
Health And Safety ◽  
Aliphatic Amines ◽  
Shielding Effect ◽  
Processing Temperature ◽  
Rubber Content ◽  
Payne Effect ◽  
Rubber Compounds ◽  
Bound Rubber

ABSTRACT Diphenyl guanidine (DPG) is the most commonly used secondary accelerator in silica-reinforced rubber compounds because of its additional positive effect on the silanization reaction and deactivation of free silanol groups that are left over after the silanization. However, because of health and safety concerns about the use of DPG, which decomposes to give highly toxic aniline during high processing temperature, safe alternatives are required. This work investigates the effect of various types of aliphatic amines having alkyl or cyclic structures and similar pKa (i.e., hexylamine [HEX], decylamine [DEC], octadecylamine [OCT], cyclohexylamine [CYC], dicyclohexylamine [DIC], and quinuclidine [QUI]) on the properties of silica-reinforced natural rubber (NR) compounds by taking the ones with DPG and without amine as references. When compared with the compound without amine, the use of all amine types reduces filler–filler interaction (i.e., the Payne effect) and enhances filler–rubber interaction, as indicated by bound rubber content and decreased heat capacity increment. The amines with alkyl chains can reduce the Payne effect and enhance cure rate to a greater extent compared with the amines with cyclic rings as a result of better accessibility toward the silica surface and a shielding effect because of less steric hindrance. The longer carbon tails on linear aliphatic amines ranging from HEX, DEC, to OCT lead to a lower Payne effect, lower heat capacity increment, higher bound rubber content, and higher modulus as well as tensile strength. Overall, the use of OCT provides silica-reinforced NR compounds with properties closest to the reference one with DPG and can act as a potential alternative for DPG.

Reinforcing Effect of Silica and Silane Fillers on the Properties of Some Natural Rubber Vulcanizates

2003 ◽  
Vol 76 (5) ◽  
pp. 1290-1310 ◽  
Author(s):  
A. Ansarifar ◽  
R. Nijhawan ◽  
T. Nanapoolsin ◽  
M. Song
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Cyclic Fatigue ◽  
Rubber Matrix ◽  
Stored Energy ◽  
Elongation At Break ◽  
Reinforcing Effect ◽  
Bound Rubber ◽  
Technical Properties ◽  
Natural Rubber Vulcanizates

Abstract The reinforcing effect of up to 6 parts per hundred rubber by weight (phr) bis- (3-triethoxysilylpropyl) tetrasulfide (TESPT), a bifunctional organosilane, on the crosslink density, bound rubber, and technical properties of some conventional accelerator/sulfur compounds of natural rubber, containing 30 phr precipitated amorphous white silica was studied. The crosslink density and bound rubber improved as a function of TESPT loading. The tensile strength, elongation at break, stored energy density at rupture, and cohesive tear strength deteriorated at low loading of TESPT, but they subsequently increased after the full amount of TESPT was introduced into the compound. The improved properties of the vulcanizate was due to the better dispersion of the filler in the rubber matrix. However, the cyclic fatigue life was adversely affected, and the hardness hardly changed as a result of adding TESPT to the rubber.

PROPERTIES OF SBR FILLED WITH CARBON BLACK AND ARAMID PULP HYBRID FILLER: COMPARISON BETWEEN PREDISPERSED ARAMID PULP AND CONVENTIONAL ARAMID PULP

2016 ◽  
Vol 89 (4) ◽  
pp. 640-652 ◽  
Author(s):  
Manuchet Nillawong ◽  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Chakrit Sirisinha
Keyword(s):  
Carbon Black ◽  
Hybrid Composites ◽  
Aramid Fiber ◽  
Rubber Content ◽  
Hybrid Filler ◽  
Fiber Loading ◽  
Bound Rubber ◽  
Extended Range ◽  
Heat Buildup ◽  
Rubber Filler

ABSTRACT Compounds of SBR incorporated with hybrid filler of carbon black (CB) and aramid pulp were prepared. The ratio of CB to aramid pulp was varied and its effects on viscoelastic and mechanical properties of the rubber were investigated. Two aramid pulp types were used in this study: conventional aramid pulp (CAP) and the predispersed aramid pulp (PAP). The rubber–filler interaction as indicated by bound rubber content decreases with increasing aramid pulp loading, regardless of the aramid pulp type. This results in a decrease in tensile and abrasion properties with increasing fiber loading. The energy dissipation properties of the hybrid composites are also poorer than those of the CB/SBR composite, as reflected by the heat buildup values. Use of predispersed aramid fiber resulted in improved dispersion of the fiber in SBR. Thus, Mooney viscosities of the PAP-filled systems are lower than those of the CAP-filled systems, but the percentages of elongation at breaks are higher. The distinct feature of aramid fiber/CB hybrid SBR composites is their high moduli over an extended range of temperatures up to 80°C that is unattainable with the use of CB alone.

scholarly journals OPTIMIZATION OF MIXING CONDITIONS FOR SILICA-REINFORCED NATURAL RUBBER TIRE TREAD COMPOUNDS

2012 ◽  
Vol 85 (2) ◽  
pp. 277-294 ◽  
Author(s):  
W. Kaewsakul ◽  
K. Sahakaro ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Natural Rubber ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Cross Linking ◽  
Mixing Conditions ◽  
Rubber Tire ◽  
Bound Rubber ◽  
Silane Coupling ◽  
Good Agreement ◽  
Key Parameter

Abstract The dump temperature and mixing interval between rubber, silica, and silane coupling agent for silica-filled natural rubber (NR) tire tread compounds using bis-triethoxysilylpropyl tetrasulfide (TESPT) as silane were optimized. The dump temperature turns out to be the key parameter governing the properties of the silica-filled NR compounds. The increase in viscosity of the compounds by changing the dump temperature from 100 to 150 °C indicates that inevitably some cross-linking of NR occurs by sulfur contained in TESPT, simultaneous with the silanization reaction between silica and silane. However, the viscosity decreases again when dump temperatures above 150 °C are applied, indicating a dominant occurrence of degradation of the NR molecules. The results are in good agreement with bound rubber contents. The overall properties indicate that a dump temperature in the range of 135–150 °C and a silica–silane–rubber mixing interval of 10 min are the most appropriate mixing conditions for silica-filled NR compounds with TESPT as coupling agent.

Influence of Fillers Surface Characteristics on Bound Rubber Properties of Filled Natural Rubber Compounds

2013 ◽  
Vol 845 ◽  
pp. 412-416 ◽  
Author(s):  
Mustafa Kamal Mazlina
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Activity ◽  
Specific Activity ◽  
Filler Particle ◽  
Surface Characteristics ◽  
Rubber Content ◽  
Rubber Compounds ◽  
Bound Rubber ◽  
Service Application

One of the most important phenomena in rubber science is the reinforcement by rigid entities, such as carbon black, clays, silicates and calcium carbonate. Thus, these fillers are added to rubber formulations to optimise properties that meet a given service application or set of performance parameters. Fillers can be divided into three categories reinforcing, semi-reinforcing and non-reinforcing. For a given elastomer and state of mix, bound rubber can be considered as a measurement of a surface activity of a filler and is considered as one of major factors in reinforcement. A strong rubber: filler interaction results in a large bound rubber content. Good dispersions and distribution of filler aggregates is also important for the full reinforcing potential of fillers to be reached. In this study, the influence of fillers on bound rubber content of Natural Rubber compounds were determined and compared. Results showed that the bound rubber content followed the trend of Carbon Black>Silica>Carbon Black>Starch. The two main filler characteristics that affect the bound rubber properties are the filler particle size and surface activity. The specific activity of the filler is determined by the physical and chemical nature of the filler surface in relation to that of elastomer. Keywords: reinforcement, surface energy

Effect of Epoxidation Level in Silica Filled Epoxidized Natural Rubber Compound on Cure, Rheological, Mechanical and Dynamic Properties

2014 ◽  
Vol 554 ◽  
pp. 71-75 ◽  
Author(s):  
Afnan Aiman Rohadi ◽  
Abdul Razak Rahmat ◽  
Mazlina Mustafa Kamal
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Small Deformation ◽  
Epoxidized Natural Rubber ◽  
Rubber Content ◽  
Silanol Groups ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Spectroscopy Studies ◽  
Work Effect

Reinforcement of rubber by precipitated silica is adversely affected due to lack of strong polymer silica bonding. Functionalized polymers interact strongly with surface silanol groups of precipitated silica. In this work, effect of variation of epoxide content in silica filled Epoxidized Natural Rubber (ENR) compound was studied namely ENR 10, 25, 37.5 and 50mol%. Increasing in epoxide level of rubber has contributed to better rubber filler interaction and lead to better mechanical properties. Meanwhile, ENR’s with greater degree of polarity has contributed significantly to higher storage moduli at small deformation and also leads to increase in bound rubber content value. Fourier transform infrared spectroscopy studies showed that the silanol groups in silica interact with ENR through formation of Si-OH bond.

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