scholarly journals Influence of Fillers and Ionic Liquids on the Crosslinking and Performance of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1656
Author(s):  
Magdalena Maciejewska ◽  
Anna Sowińska
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Mechanical Performance ◽  
Mechanical And Thermal Properties ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
And Performance ◽  
Surface Silica

This work concerns the effect of fillers and ionic liquids on the cure characteristics of natural rubber (NR) compounds, as well as the mechanical and thermal properties of the vulcanizates. Three types of white filler were applied, such as cellulose, nanosized silica and hydrotalcite, to modify the performance of NR composites. Additionally, ionic liquids (ILs) with bromide anion and different cations, i.e., 1-butyl-3-methylimidazolium (Bmi) and 1-butyl-3-methylpyrrolidinium (Bmpyr), were used to improve the cure characteristics of NR compounds and functional properties of the vulcanizates. The type of filler and the structure of ILs were proved to affect the rheometric properties and cure characteristics of NR compounds as well as the performance of the NR vulcanizates. Owing to the adsorption of curatives onto the surface, silica reduced the activity of the crosslinking system, prolonging the optimal vulcanization time of NR compounds and reducing the crosslinking degree of the elastomer. However, silica-filled NR exhibited the highest thermal stability. Hydrotalcite increased the crosslink density and, consequently, the mechanical properties of the vulcanizates, but deteriorated their thermal stability. ILs beneficially influenced the cure characteristics of NR compounds, as well as the crosslink density and mechanical performance of the vulcanizates, particularly those filled with silica. Cellulose did not significantly affect the vulcanization of NR compounds and crosslink density of the vulcanizates compared to the unfilled elastomer, but deteriorated their tensile strength. On the other hand, cellulose improved the thermal stability and did not considerably alter the damping properties of the vulcanizates.

scholarly journals Bis(trifluoromethylsulfonyl)imide Ionic Liquids Applied for Fine-Tuning the Cure Characteristics and Performance of Natural Rubber Composites

2021 ◽  
Vol 22 (7) ◽  
pp. 3678
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Anna Grajewska
Keyword(s):  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
Physico Chemical ◽  
Elastomer Composites ◽  
And Performance

The goal of this work was to apply ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide anion (TFSI) for fine-tuning the cure characteristics and physico-chemical properties of elastomer composites based on a biodegradable natural rubber (NR) matrix. ILs with TFSI anion and different cations, such as alkylpyrrolidinium, alkylammonium, and alkylsulfonium cations, were applied to increase the efficiency of sulfur vulcanization and to improve the performance of NR composites. Thus, the influence of ILs on the vulcanization of NR compounds, as well as crosslink density and physical properties of NR vulcanizates, including tensile properties, thermal stability, and resistance to thermo-oxidative aging was explored. The activity of ILs seems to be strongly dependent on their cation. Pyrrolidinium and ammonium ILs effectively supported the vulcanization, reducing the optimal vulcanization time and temperature of NR compounds and increasing the crosslink density of the vulcanizates. Consequently, vulcanizates with these ILs exhibited higher tensile strength than the benchmark without IL. On the other hand, sulfonium ILs reduced the torque increment owing to the lower crosslinking degree of elastomer but significantly improved the resistance of NR composites to thermo-oxidation. Thus, TFSI ILs can be used to align the curing behavior and performance of NR composites for particular applications.

scholarly journals The Influence of Curing Systems on the Cure Characteristics and Physical Properties of Styrene–Butadiene Elastomer

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5329
Author(s):  
Magdalena Maciejewska ◽  
Monika Siwek
Keyword(s):  
Zinc Oxide ◽  
Physical Properties ◽  
Crosslink Density ◽  
Mechanical Performance ◽  
Multifunctional Additive ◽  
Cure Characteristics ◽  
And Performance ◽  
Styrene Butadiene ◽  
Nanosized Silica ◽  
Curing Systems

The goal of this work is to study the influence of different curing systems on the cure characteristics and performance of styrene–butadiene elastomer (SBR) filled with carbon black or nanosized silica. A multifunctional additive for rubber compounds, namely Activ8, was applied as an additional activator and accelerator to increase the efficiency of sulfur vulcanization and to reduce the content of zinc oxide elastomers cured in the presence of 2-mercaptobenzothizole or 1,3-diphenylguanidine as a primary accelerator. The influence of the curing system composition on the crosslink density and physical properties of SBR vulcanizates, such as mechanical properties, thermal stability, and resistance to thermo-oxidative aging, is also reported. Activ8 effectively supports the vulcanization of SBR compounds, especially filled with nanosized silica. It reduces the optimal vulcanization time of SBR compounds and increases the crosslink density of the vulcanizates. Moreover, vulcanizates with Activ8 exhibit higher tensile strength and better damping properties than elastomer with zinc oxide. Activ8 allows the amount of ZnO to be reduced by 40% without detrimental effects on the crosslink density and mechanical performance compared to the vulcanizates conventionally crosslinked with ZnO. This is an important ecological goal since ZnO is classified as being toxic to aquatic species.

scholarly journals The effects of alkanolamide addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR) / chloroprene rubber (CR) blends

2018 ◽  
Vol 34 ◽  
pp. 01030 ◽  
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar ◽  
Hanafi Ismail
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Tensile Modulus ◽  
Palm Stearin ◽  
Swelling Behaviour ◽  
Elongation At Break ◽  
Cure Characteristics ◽  
Chloroprene Rubber

Effects of alkanolamide (ALK) addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR)/chloroprene rubber (CR) blends were investigated. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine, and incorporated into the silica-filled NR/CR blends as a non-toxic rubber additive. The ALK loadings were 0.0, 1.0, 3.0, 5.0 and 7.0 phr. It was found that the ALK exhibited shorter scorch and cure times and higher elongation at break of the silica-filled NR/CR blends. The ALK also exhibited higher torque differences, tensile modulus and tensile strength at a 1.0 phr of ALK loading and then decreased with further increases in the ALK loading. The swelling measurement proved that the 1.0 phr loading of ALK caused the highest degree in crosslink density of the silica-filled NR/CR blends.

Effect of vulcanization time on crosslink density and aging performance of natural rubber composites

2020 ◽  
Vol 62 (8) ◽  
pp. 858-862
Author(s):  
Ece Unur Yilmaz ◽  
Ahu Kor Dayioglu ◽  
Seda Balaban
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Operating Conditions ◽  
Rubber Composites ◽  
Rubber Mixture ◽  
Natural Rubber Composites ◽  
Different Temperatures ◽  
Auto Parts

Abstract Natural rubber composites are widely used in the automotive industry because of their improved viscoelastic characteristics that are mostly governed by crosslink density. However, rubber parts suffer deterioration of performance over long service lives. Therefore, optimization of crosslink density and prediction of changes in physico-mechanical properties over time at elevated temperatures is extremely important for the production of safe auto parts. In this work, the effect of vulcanization time on crosslink density and thus the performance and lifetime of natural rubberbased auto parts was investigated. The natural rubber mixture prepared in this context was vulcanized for 3, 5, 10 and 15 minutes at a constant temperature of 160 °C. The crosslink density of each vulcanizite was determined by equilibrium swelling tests and the Flory-Rehner equation. The maximum crosslink density (10.75 × 10-5 mol × cm-3) and the minimum permanent compression set values (10 % at 70 °C and 25 % at 100 °C) were recorded for the sample vulcanized for 10 minutes (v10). Aging behavior of the samples were investigated by stress relaxation tests performed at 85 °C, 100 °C and 120 °C. The service lives of the vulcanizites at different temperatures were predicted by linear Arrhenius fits of degradation times. The sample vulcanized for 10 minutes (v10) was shown to exhibit a service life of 2282 hours at 70 °C in air and the optimum physico-mechanical performance under real operating conditions. The performance and lifetime prediction procedure used in this work could be employed in an early design of rubber components for specific applications.

scholarly journals Ionic Liquids and Calcium Oxide Grafted with Allylmalonic Acid Applied to Support the Peroxide Crosslinking of an Ethylene–Propylene Copolymer

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3260
Author(s):  
Magdalena Maciejewska
Keyword(s):  
Ionic Liquids ◽  
Silica Nanoparticles ◽  
Calcium Oxide ◽  
Crosslink Density ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
And Performance ◽  
Crosslinking Reactions ◽  
Thermal Stability Of

Nanosized calcium oxide (CaO) featuring a surface grafted with allylmalonic acid (ALA) was used to increase the efficiency of the peroxide crosslinking of an ethylene–propylene copolymer (EPM) filled with silica nanoparticles. In this study, 1-butyl-3-methylimidazolium ionic liquids (ILs) with different anions were applied to improve the dispersion of CaO/ALA and silica nanoparticles in the EPM copolymer, as well as to catalyze the interfacial crosslinking reactions. In this article, we discuss the effects of CaO/ALA and ILs on the curing characteristics, vulcanization temperature, crosslink density, mechanical properties, and thermal stability of EPM, as well as the resistance of EPM to weather aging. The CaO/ALA with ILs reduced the vulcanization time of the rubber compounds without a significant effect on the vulcanization temperature. Their application resulted in an increased vulcanizate crosslink density, as well as improved tensile strength compared to the pure peroxide system. The influence of 1-butyl-3-methylimidazolium ILs on EPM vulcanization and performance depends on the anion present in the molecules of the ionic liquid. The most active IL seems to be that with the tetrafluoroborate anion.

Indole-based high-performance polymeric materials with enhanced mechanical and thermal properties via cation-π interaction

2019 ◽  
Vol 32 (6) ◽  
pp. 662-668
Author(s):  
Xiao-fang Guan ◽  
Cong Liao ◽  
Li Yang ◽  
Guan-jun Chang
Keyword(s):  
Thermal Stability ◽  
Heat Resistance ◽  
Self Assembly ◽  
High Performance ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Design Strategy ◽  
Mechanical And Thermal Properties ◽  
Innovative Design ◽  
High Performance Polymers

The preparation of high-performance polymeric materials with both excellent overall mechanical properties and heat resistance remains a considerable challenge. Inspired by the delicate self-assembly processes in nature, a facile strategy is reported for the preparation of high-performance polymeric materials with enhanced mechanical strength and improved thermal stability. In this instance, we successfully constructed a cation- π cross-linked polyimide (Na-poly(aryl indole) imide (Na-PINI)) film with enhanced mechanical performance and heat resistance (∼490°C). This work presents an innovative design strategy for realizing robust polymeric materials with integrated strength and thermal stability; the cation- π interaction is demonstrated to be a new method that may achieve many useful properties for high-performance polymers.

Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

2017 ◽  
Vol 751 ◽  
pp. 337-343 ◽  
Author(s):  
Chanchai Thongpina ◽  
Chaiwat Tippuwanan ◽  
Kwanchai Buaksuntear ◽  
Teerani Chuawittayawuta
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Performance ◽  
Organic Peroxide ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Cloisite 30B

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. Tm in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

Cure Characteristics and Physical Properties of Imperata cylindrica Activated Carbon Filled SMR L Compounding

2015 ◽  
Vol 815 ◽  
pp. 44-48
Author(s):  
M.H. Fatin ◽  
N.Z. Noriman ◽  
Kamarudin Husin ◽  
M.Z. Salihin ◽  
N.R. Munirah ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Natural Rubber ◽  
Physical Properties ◽  
Crosslink Density ◽  
Filler Loading ◽  
Rubber Compound ◽  
Maximum Torque ◽  
Cure Characteristics ◽  
Cure Time ◽  
Minimum Torque

The potential of activated carbon as a filler in rubber compound has been reviewed .Cure characteristics and physical properties ofImperataCylindricaactivated carbon filled natural rubber of Standard Malaysian Rubber (SMR L) were studied. SMR L was used as the elastomer and the composition of filler loading were varied from 0-50 parts per hundred rubber (phr). A semi-efficient vulcanization system was used throughout the study. The cure characteristics of the rubber compound was determined by using rheometer. The samples of hardness and resilience were measured by durometer shore A and Wallace Dunlop Tripsometer. Cure characteristics showed that cure time, t90and scorch time,t2increased as increased filler loading which indicate poor interaction between rubber and filler which slow down the vulcanization time. Minimum torque,MLand maximum torque,MHincreased as increased filler loading due to the low processability of the SMR L compounds. Crosslink density and hardness exhibit increment as increased filler loading due to increase rigidity of the SMR L compounds. The resilience will decrease correspondingly as increased in rigidity of the compounds.

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