Dispersion of Layered Organosilicates in Isobutylene-Based Elastomers

2006 ◽  
Vol 79 (2) ◽  
pp. 281-306 ◽  
Author(s):  
Andy H. Tsou ◽  
Matthew B. Measmer
Keyword(s):  
Aspect Ratio ◽  
Carbon Black ◽  
Layered Silicate ◽  
Tertiary Amines ◽  
Aspect Ratios ◽  
Silicate Nanocomposites ◽  
Dispersion State ◽  
Planar Orientation ◽  
Internal Mixer ◽  
Better Than

Abstract Dispersion morphologies of polymer-layered silicate nanocomposites based on either brominated poly(isobutylene-co-para-methylstyrene), BIMSM, or brominated poly(isobutylene-co-isoprene), BIIR, and an organosilicate, dimethylditallow ammonium-exchanged montmorillonite, Cloisite™ 6A, with and without N660 carbon black fillers were examined using SAXS, WAXS, AFM, and TEM. These compounds were prepared using an internal mixer and cured for property measurements. Due to the observed partial orientation of organosilicates and their possible heterogeneous intercalation, degrees of exfoliation and dispersion of organosilicates in BIMSM and BIIR were unable to be characterized and quantified simply by TEM, AFM, or SAXS alone. Instead, using the projected aspect ratio of organosilicates in BIMSM or BIIR, extracted from Gusev-Lusti equation based on measured permeability ratios, was found to provide a relative measure of their dispersion state. Since better dispersion, higher planar orientation, and/or increasing extent of exfoliation lead to higher aspect ratio, this calculated aspect ratio was used as a measure of organosilicate dispersion in BIMSM and BIIR compounds. According to experimentally extracted projected aspect ratios, it was found that BIMSM disperses organosilicates better than BIIR and that carbon black filler does not affect the organosilicate dispersion in BIMSM. Addition of tertiary amines in BIMSM enhances the dispersion of organosilicates, possibly through favorable interactions between organosilicates and quaternary ammonium functionalized BIMSM, resulting in further reduction in permeability.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part III: Results of Supplementary and UTQG Treadwear Test Series

1986 ◽  
Vol 14 (4) ◽  
pp. 235-263
Author(s):  
A. G. Veith
Keyword(s):  
Carbon Black ◽  
Comprehensive Evaluation ◽  
Work Intensity ◽  
Generic Type ◽  
Aspect Ratios ◽  
Index Variation ◽  
Primary Determinant ◽  
Severity Levels ◽  
High Test ◽  
Better Than

Abstract The effect of tread compound variation on tire treadwear was studied using bias and radial tires of two aspect ratios. Compound variations included types of rubber and carbon black as well as the levels of carbon black, process oil, and curatives. At low to moderate test severity, SBR and an SBR/BR blend performed better than NR while at high test severity NR and SBR were better than the SBR/BR blend. The SBR/BR blend was the best at low severity testing. Higher structure and higher surface area carbon black gave improved treadwear at all severity levels. The concept of a “frictional work intensity” as the primary determinant of treadwear index variation with test severity is proposed. Some factors which influence frictional work intensity are discussed.

Thermal stability of ammonium salts as compatibilizers in polymer/layered silicate nanocomposites

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Maurizio Galimberti ◽  
Marco Martino ◽  
Monica Guenzi ◽  
Gabriella Leonardi ◽  
Attilio Citterio
Keyword(s):  
Thermal Stability ◽  
Layered Silicate ◽  
Ammonium Cation ◽  
Ammonium Salts ◽  
Chloride Salt ◽  
Tertiary Amines ◽  
Silicate Nanocomposites ◽  
Thermal Stability Of ◽  
Isoprene Rubber

AbstractThermal stability of alkyl and arylalkyl quaternary ammonium cation (onium) in starting chloride salt, in organoclay obtained after exchange with montmorillonite (MMT) and after mixing of the organoclay with isoprene rubber was examined using conventional TGA and by mass spectrometry pyrolysis/GC-MS. Degradation was observed to occur at T ≥ 170 °C for organoclays and the main volatile compounds were identified as tertiary amines, chloroalkanes and alkenes. Mechanisms for their formation are proposed and the role of residual onium chloride and basic centers of layered silicate is discussed.

Materials for food packaging applications based on bio-based polymer nanocomposites

2015 ◽  
Vol 30 (2) ◽  
pp. 143-173 ◽  
Author(s):  
Seyed Ahmad Attaran ◽  
Azman Hassan ◽  
Mat Uzir Wahit
Keyword(s):  
Polymer Nanocomposites ◽  
Food Packaging ◽  
Layered Silicate ◽  
Barrier Properties ◽  
Packaging Materials ◽  
Natural Polymer ◽  
Plastic Packaging ◽  
Aspect Ratios ◽  
Nanoparticle Surface ◽  
Silicate Nanocomposites

Concerns about environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer demand for high-quality food products have led to increased interest in the development of biodegradable packaging materials using annually renewable natural biopolymers. Inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low barrier properties can be recovered by applying nanocomposite technology. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to large nanoparticle surface area and their significant aspect ratios. Additionally, natural biopolymer is susceptible to microorganisms, resulting in good biodegradability, which is one of the most promising aspects of its incorporation in packaging materials and industries. The present review article explains the various categories of nanoclay and bio-based polymer-based composites with particular regard to their application as packaging materials. It also gives an overview of the most recent advances and emerging new aspects of nanotechnology for development of composites for environmentally compatible food packaging materials.

scholarly journals Modeling of Tensile Modulus of Polyolefin-Layered Silicate Nanocomposites: Modified Halpin Tsai Models

2012 ◽  
Vol 21 (5) ◽  
pp. 096369351202100
Author(s):  
Vikas Mittal
Keyword(s):  
Aspect Ratio ◽  
Tensile Modulus ◽  
Layered Silicate ◽  
Adhesion Forces ◽  
Element Analysis ◽  
Tem Analysis ◽  
Simple Modification ◽  
Silicate Nanocomposites ◽  
Average Aspect Ratio ◽  
Modulus Reduction

The modified forms of Halpin Tsai model for the prediction of tensile modulus of polyolefin-layered silicate nanocomposites are discussed. The assumptions used in the conventional model like perfect alignment of the particulate filler, uniform shape and size of the filler particles as well as interfacial adhesion between the polymer and filler surface do not hold true in the case of polymer nanocomposites especially using polyolefinic matrices. The modulus reduction factors suggested for polar nanocomposites are also dependent on the polymer nature as well as filler morphology in the composite, thus, are not applicable directly to the polyolefin composites. A master curve could be generated for polyolefin nanocomposites which provided more accurate modulus reduction factor value based on the average aspect ratio of the filler. Incorporation of the effects of incomplete exfoliation as well as filler misalignment though improved the prediction capabilities of the model, however, it still did not match the predictions generated from finite element analysis or TEM analysis. The effect of absence of adhesion forces at the interface was incorporated by suggesting simple modification to the modified Halpin Tsai model equation. Master curves could be generated which predicted the relative tensile modulus of the composites accurately if the value of average aspect ratio was known.

Influence of Agitation Equipment on Reinforcing Effect and Dispersion State of Cellulose Nano-Fibers in Natural Rubber

2017 ◽  
Vol 754 ◽  
pp. 23-26
Author(s):  
Sho Omori ◽  
Takayuki Morita ◽  
Koki Matsumoto ◽  
Asahiro Nagatani ◽  
Tatsuya Tanaka
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Reinforcing Effect ◽  
X Ray ◽  
Centrifugal Mixer ◽  
Vulcanized Rubber ◽  
Biomass Resource ◽  
Dispersion State ◽  
Biomass Resources ◽  
Internal Mixer

There are many rubber products like tires, and reinforcing agents derived from fossil resources such as carbon black (CB) are used for them. However, in recent years, conversion to biomass resources has been demanded due to problems such as depletion of fossil resources. Therefore, we have studied the composite of natural rubber (NR) reinforced with cellulose nano-fibers (CNF), which has attracted attention as a next-generation biomass resource. It is very difficult to uniformly disperse CNF in the conventional kneading process. Therefore, it is preferable to agitate CNF in NR latex. Then, it is necessary to study the optimum agitation equipment of CNF. In this study, the reinforcing effect by CNF was investigated when the agitation equipment was changed. Agitation of NR latex and CNF was carried out by a hand, a homogenizer, a dispersion mixer, and planetary centrifugal mixer. Thereafter, agitated materials were dried and masterbatches were made. Furthermore, the masterbatch and vulcanizing agents were kneaded using an internal mixer. Tensile test and X-ray CT observation of the prepared vulcanized rubber sheets were carried out to evaluate the reinforcing effect and dispersion state of CNF. As a result, the planetary centrifugal mixer was most useful to uniformly disperse CNF.

The Aspect Ratio and Gas Permeation in Polymer-Layered Silicate Nanocomposites

2004 ◽  
Vol 25 (12) ◽  
pp. 1145-1149 ◽  
Author(s):  
Maged A. Osman ◽  
Vikas Mittal ◽  
Hans Rudolf Lusti
Keyword(s):  
Aspect Ratio ◽  
Layered Silicate ◽  
Gas Permeation ◽  
Silicate Nanocomposites

scholarly journals Effect of Filler Synergy and Cast Film Extrusion Parameters on Extrudability and Direction-Dependent Conductivity of PVDF/Carbon Nanotube/Carbon Black Composites

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2992
Author(s):  
Beate Krause ◽  
Karina Kunz ◽  
Bernd Kretzschmar ◽  
Ines Kühnert ◽  
Petra Pötschke
Keyword(s):  
Aspect Ratio ◽  
Carbon Black ◽  
Vinylidene Fluoride ◽  
Extrusion Direction ◽  
Small Scale ◽  
Melt Mixing ◽  
Film Extrusion ◽  
Contact Points ◽  
Aspect Ratios ◽  
Cast Film

In the present study, melt-mixed composites based of poly (vinylidene fluoride) (PVDF) and fillers with different aspect ratios (carbon nanotubes (CNTs), carbon black (CB)) and their mixtures in composites were investigated whereby compression-molded plates were compared with melt-extruded films. The processing-related orientation of CNTs with a high aspect ratio leads to direction-dependent electrical and mechanical properties, which can be reduced by using mixed filler systems with the low aspect ratio CB. An upscaling of melt mixing from small scale to laboratory scale was carried out. From extruded materials, films were prepared down to a thickness of 50 µm by cast film extrusion under variation of the processing parameters. By combining CB and CNTs in PVDF, especially the electrical conductivity through the film could be increased compared to PVDF/CNT composites due to additional contact points in the sample thickness. The alignment of the fillers in the two directions within the films was deduced from the differences in electrical and mechanical film properties, which showed higher values in the extrusion direction than perpendicular to it.

Thermally-cured and e-beam-cured epoxy layered-Silicate nanocomposites

2003 ◽  
Vol 49 (6) ◽  
pp. 473-480 ◽  
Author(s):  
Chenggang Chen ◽  
David Curliss
Keyword(s):  
Layered Silicate ◽  
Silicate Nanocomposites

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

Sign in / Sign up

Export Citation Format

Share Document