scholarly journals Preparation and Charaterization of Treated BIS [3-(Triethoxysilyl) Propyl] Tetrasulfide (Si-69) -HYBRID CB/PCC Fillers Reinforced NR/SBR Composites: Cure Characteristic, Mooney Viscosity and Cross-Link Density

2018 ◽  
Vol 27 (6) ◽  
pp. 096369351802700
Author(s):  
Siti Nur Liyana Mamauod ◽  
Basirah Fauzi ◽  
Nor Atiqah Suhaimi ◽  
Roslinda Fauzi ◽  
Ahmad Zafir Romli
Keyword(s):  
Crosslink Density ◽  
Network Formation ◽  
Cross Link ◽  
Hybrid Filler ◽  
Curing Characteristics ◽  
Roll Mill ◽  
Link Density ◽  
Cross Link Density ◽  
Mooney Viscosity ◽  
Cure Characteristic

Hybridization of silanized CB/PCC filler reinforced NR/SBR blends was prepared on a two roll mill. The si-CB/PCC composites were vulcanized via a conventional sulphur system at 180°C. The primary aims of this research are to scrutinize the effects of different concentration of si treated hybrid CB/PCC fillers ranging from 2 wt. % to 10 wt. % on the NR/SBR blends properties towards the curing characteristics, viscosity and crosslink density. In this work, a positive correlation was found between silane content on the hybrid filler surface and NR/SBR blend properties. It was found that at 6% of Si 69 concentration (F4) provided improvement in crosslink density and mooney viscosity properties. Increment of crosslink density in the blends would increase the viscosity and it may be due to the network formation between the treated fillers and rubber molecules. Moreover, the incorporation of treated fillers accelerates the curing process due to the surface activation and hence leads to tightly contact between filler-rubber phases.

Elongation at Break as a Measure of Cross-Link Density in Vulcanized Elastomers

1966 ◽  
Vol 39 (3) ◽  
pp. 726-739 ◽  
Author(s):  
E. DiGiulio ◽  
G. Bellini ◽  
G. V. Giandinoto
Keyword(s):  
Crosslink Density ◽  
Cross Linking ◽  
Total Degree ◽  
Cross Link ◽  
Elongation Ratio ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
First Approximation ◽  
Link Density ◽  
Cross Link Density

Abstract After recalling the reaction mechanism suggested for the crosslinking of ethylene propylene copolymers with organic peroxides, the authors consider the relation between concentration of curing agent and crosslink density. It is experimentally found that, as a first approximation, the elongation ratio at break of vulcanizates (unfilled or filled with small quantities of carbon black) is a function of molar concentration of peroxide only: αR=K/P1/2 This relation can be theoretically justified on the basis of the extensibility of polymer chain segments and of the criterion for rupture originally put forward by Taylor and Darin. By applying the above relation to ethylene propylene copolymers it is possible to evaluate the influence of the chain-splitting reaction during cross-linking. The reciprocal of the square of elongation ratio at break (1/αR2) measures the total degree of crosslinking.

scholarly journals Thermomechanical Devulcanisation of Ethylene Propylene Diene Monomer (EPDM) Rubber and Its Subsequent Reintegration into Virgin Rubber

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1116
Author(s):  
Dávid Zoltán Pirityi ◽  
Kornél Pölöskei
Keyword(s):  
Tensile Tests ◽  
Ethylene Propylene Diene Monomer ◽  
Cross Link ◽  
Rubber Mixture ◽  
Ethylene Propylene ◽  
Rubber Waste ◽  
Roll Mill ◽  
Link Density ◽  
Cross Link Density ◽  
Curing Agents

Rubber waste remains a challenge for material science because its covalently cross-linked structure hinders the establishment of the circular economy of rubber. Devulcanisation may provide a solution, as it converts rubber vulcanisates back into their original, uncured state. Devulcanised rubber may be revulcanised or incorporated into virgin rubber, thus waste is utilized and the use of primary resources is reduced at the same time. In this paper, we treated sulphur-cured EPDM (ethylene propylene diene monomer) rubber on a two-roll mill at various temperatures and frictions. We determined the effectiveness of devulcanisation via Horikx’s analysis, which suggested that low devulcanisation temperatures would result in a 50% decrease in cross-link density with minimal polymer degradation. The devulcanisate was recycled via two methods: (a) revulcanisation with extra curing agents, and (b) mixing it with various amounts of the original rubber mixture, preparing rubber samples with 25, 50, 75, and 100 wt% recycled content. Tensile tests revealed that the samples’ elastic properties were severely compromised at 75 and 100 wt% devulcanisate contents. However, tensile strength decreased only by 15% and 20% for revulcanisates containing 25% and 50% recycled rubber, respectively.

scholarly journals Effect of the cure time on the Mechanical Properties of Silicone Rubber used as Socket Liners

2022 ◽  
Vol 961 (1) ◽  
pp. 012100
Author(s):  
Ahmed K Hassan ◽  
Zuhair Jabbar Abdul Ameer
Keyword(s):  
Silicone Rubber ◽  
Crosslink Density ◽  
Skin Inflammation ◽  
Moisture Stress ◽  
Curing Time ◽  
Cross Link ◽  
Local Pressure ◽  
Link Density ◽  
Cure Time ◽  
Cross Link Density

Abstract This work is focused on the upper part of the prosthesis which is called a socket, it is in contact connect with the amputated part. The shear force between skin and socket, local pressure, sweating, and bacteria generation, all lead to skin inflammation and a bad smell. Consequently, the prosthesis became uncomfortable for a patient. To address this issue silicone rubber liners is proposed to use because it can absorb moisture, stress distribution, and anti-bacterial. The curing time and temperature are important factors for determining crosslink density, from the results obtained, can be noticed that, the cross-link density can greatly affect the silicone rubber properties, it can have a direct effect on the tensile strength, modulus of elasticity, percentage of elongation as well as the water absorption, and the cure time (15 min.) shoes the best resalt. As a result, using it making the prosthesis more comfortable and acceptable to the patient. In this paper, the effect of cure time on physical properties was studied.

scholarly journals Multivalency in healable supramolecular polymers: the effect of supramolecular cross-link density on the mechanical properties and healing of non-covalent polymer networks

2014 ◽  
Vol 5 (11) ◽  
pp. 3680-3688 ◽  
Author(s):  
Lewis R. Hart ◽  
James H. Hunter ◽  
Ngoc A. Nguyen ◽  
Josephine L. Harries ◽  
Barnaby W. Greenland ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Blends ◽  
Crosslink Density ◽  
Polymer Networks ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density

Mechanical properties of healable supramolecular polymer blends correlate to non-covalent “crosslink density”.

Boron nitride for modification of rubber based on isoprene elastomer

2020 ◽  
pp. 105-112
Author(s):  
K. S. Zhansakova ◽  
E. N. Eremin ◽  
G. S. Russkikh ◽  
O. V. Kropotin
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Gradual Increase ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Cross Link ◽  
Start Time ◽  
Link Density ◽  
Cross Link Density ◽  
Isoprene Rubber

The work studies vulcanization characteristics of elastomers based on isoprene rubber filled with carbon black N330 and boron nitride (BN). The influence of the boron nitride (BN) concentration on technological, dynamic, physical and mechanical properties of elastomers has been researched. The application of boron nitride for producing rubber with good properties has been considered. With a gradual increase of the inert filler BN concentration up to 35%, a decrease in the curing rate by 33% and polymer cross-link density by 26% is observed. Moreover, the start time of vulcanization increases by almost 300%, the optimal curing time by 200%.

Mechanical and structural consequences of associative dynamic cross-linking in acrylic diblock copolymers

2021 ◽  
Author(s):  
Jacob Ishibashi ◽  
Ian Pierce ◽  
Alice Chang ◽  
Aristotelis Zografos ◽  
Bassil El-Zaatari ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Network Connectivity ◽  
Ethyl Acrylate ◽  
Cross Linking ◽  
Cross Link ◽  
Block Polymers ◽  
Link Density ◽  
Cross Link Density

<p>The composition of low-T<sub>g</sub> <i>n</i>-butylacrylate-<i>block</i>-(acetoxyaceto)ethyl acrylate block polymers is investigated as a strategy to tune the properties of dynamically cross-linked vinylogous urethane vitrimers. As the proportion of the cross-linkable block is increased, the thermorheological properties, structure, and stress relaxation evolve in ways that cannot be explained by increasing cross-link density alone. Evidence is presented that network connectivity defects such as loops and dangling ends are increased by microphase separation. The thermomechanical and viscoelastic properties of block copolymer-derived vitrimers arise from the subtle interplay of microphase separation and network defects.</p><div><br></div><p></p>

Mechanical behavior of poly(methyl methacrylate)-based ionogels

Soft Matter ◽  
2014 ◽  
Vol 10 (40) ◽  
pp. 7993-8000 ◽  
Author(s):  
Mingyu Li ◽  
Jianyu Li ◽  
Hui Na ◽  
Joost J. Vlassak
Keyword(s):  
Methyl Methacrylate ◽  
Mechanical Behavior ◽  
Fracture Energy ◽  
Cross Link ◽  
Poly Methyl Methacrylate ◽  
Link Density ◽  
Cross Link Density ◽  
The Cross ◽  
The Ideal

We demonstrate that the fracture energy of ionogels correlates inversely with the cross-link density. The behavior of ionogels is well captured by the ideal elastomeric gel model.

Sign in / Sign up

Export Citation Format

Share Document