scholarly journals Influence of Bio-Based Plasticizers on the Properties of NBR Materials

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2095 ◽  
Author(s):  
Md Mahbubur Rahman ◽  
Katja Oßwald ◽  
Katrin Reincke ◽  
Beate Langer

A high number of technical elastomer products contain plasticizers for tailoring material properties. Some additives used as plasticizers pose a health risk or have inadequate material properties. Therefore, research is going on in this field to find sustainable alternatives for conventional plasticizers. In this paper, two modified bio-based plasticizers (epoxidized esters of glycerol formal from soybean and canola oil) are of main interest. The study aimed to determine the influence of these sustainable plasticizers on the properties of acrylonitrile–butadiene rubber (NBR). For comparison, the influence of conventional plasticizers, e.g., treated distillate aromatic extract (TDAE) and Mesamoll® were additionally investigated. Two types of NBR with different ratios of monomers formed the polymeric basis of the prepared elastomers. The variation of the monomer ratio results in different polarities, and therefore, compatibility between the NBR and plasticizers should be influenced. The mechanical characteristics were investigated. In parallel, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were performed and filler macro-dispersion was determined. Bio-based plasticizers were shown to have better mechanical and thermal properties compared to conventional plasticizers. Further, thermo-oxidative aging was realized for 500 h, and afterwards, mechanical characterizations were done. It was observed that bio-based plasticizers have almost the same aging properties compared to conventional plasticizers.

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1251 ◽  
Author(s):  
Anja Kömmling ◽  
Matthias Jaunich ◽  
Payam Pourmand ◽  
Dietmar Wolff ◽  
Mikael Hedenqvist

Determining a suitable and reliable end-of-lifetime criterion for O-ring seals is an important issue for long-term seal applications. Therefore, seal failure of ethylene propylene diene rubber (EPDM) and hydrogenated nitrile butadiene rubber (HNBR) O-rings aged in the compressed state at 125 °C and at 150 °C for up to 1.5 years was analyzed and investigated under static conditions, using both non-lubricated and lubricated seals. Changes of the material properties were analyzed with dynamic-mechanical analysis and permeability experiments. Indenter modulus measurements were used to investigate DLO effects. It became clear that O-rings can remain leak-tight under static conditions even when material properties have already degraded considerably, especially when adhesion effects are encountered. As a feasible and reliable end-of-lifetime criterion for O-ring seals under static conditions should include a safety margin for slight dimensional changes, a modified leakage test involving a small and rapid partial decompression of the seal was introduced that enabled determining a more realistic but still conservative end-of-lifetime criterion for an EPDM seal.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 698
Author(s):  
Selin Sökmen ◽  
Katja Oßwald ◽  
Katrin Reincke ◽  
Sybill Ilisch

High compatibility and good rubber–filler interactions are required in order to obtain high quality products. Rubber–filler and filler–filler interactions can be influenced by various material factors, such as the presence of processing aids. Although different processing aids, especially the plasticizers, and their effects on compatibility have been investigated in the literature, their influence on rubber–filler interactions in highly active filler reinforced mixtures is not explicit and has not been investigated in depth. For this purpose, the influence of treated distillate aromatic extract (TDAE) oil content and its addition time on interactions between silica and rubber chains were investigated in this study. Rubber–filler and filler–filler interactions of uncured and cured silica-filled SBR/BR blends were characterized by using rubber layer L concept and dynamic mechanical analysis, whereas mechanical properties were studied by tensile test and Shore A hardness. Five parts per hundred rubber (phr) TDAE addition at 0, 1.5, and 3 min of mixing were characterized to investigate the influence of TDAE addition time on rubber–filler interactions. It was observed that addition time of TDAE can influence the development of bounded rubber structure and the interfacial interactions, especially at short time of mixing, less than 5 min. Oil addition with silica at 1.5 min of mixing resulted in fast rubber layer development and a small reduction in storage shear modulus of uncured blends. The influence of oil content on rubber–filler and filler–filler interactions were investigated for the binary blends without oil, with 5 and 20 phr TDAE content. The addition of 5 phr oil resulted in a slight increase in rubber layer and 0.05 MPa reduction in Payne effect of uncured blends. The storage tensile modulus of vulcanizates at small strains decreased from 13.97 to 8.28 MPa after oil addition. Twenty parts per hundred rubber (phr) oil addition to binary blends caused rubber layer L to decrease from 0.45 to 0.42. The storage tensile modulus of the vulcanizates and its reduction with higher amplitudes were incontrovertibly high among the vulcanizates with lower oil content, which were 13.57 and 4.49 MPa, respectively. When any consequential change in mechanical properties of styrene–butadiene rubber (SBR)/butadiene rubber (BR) blends could not be observed at different TDAE addition time, increasing amount of oil in blends enhanced elongation at break, and decreased Shore A hardness and tensile strength.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Wojciech Zakrzewski ◽  
Maciej Dobrzynski ◽  
Wojciech Dobrzynski ◽  
Anna Zawadzka-Knefel ◽  
Mateusz Janecki ◽  
...  

Nanotechnology has gained importance in recent years due to its ability to enhance material properties, including antimicrobial characteristics. Nanotechnology is applicable in various aspects of orthodontics. This scientific work focuses on the concept of nanotechnology and its applications in the field of orthodontics, including, among others, enhancement of antimicrobial characteristics of orthodontic resins, leading to reduction of enamel demineralization or control of friction force during orthodontic movement. The latter one enables effective orthodontic treatment while using less force. Emphasis is put on antimicrobial and mechanical characteristics of nanomaterials during orthodontic treatment. The manuscript sums up the current knowledge about nanomaterials’ influence on orthodontic appliances.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 616
Author(s):  
Ján Kruželák ◽  
Andrea Kvasničáková ◽  
Klaudia Hložeková ◽  
Rastislav Dosoudil ◽  
Marek Gořalík ◽  
...  

In the present work, composite materials were prepared by incorporation of manganese-zinc ferrite, carbon black and combination of ferrite and carbon black into acrylonitrile-butadiene rubber (NBR). For cross-linking of composites, standard sulfur-based curing system was applied. The main goal was to investigate the influence of the fillers on the physical-mechanical properties of composites. Then, the electromagnetic absorption shielding ability was investigated in the frequency range 1 MHz–3 GHz. The results revealed that composites filled with ferrite provide sufficient absorption shielding performance in the tested frequency range. On the other hand, ferrite behaves as an inactive filler and deteriorates the physical-mechanical characteristics of composites. Carbon black reinforces the rubber matrix and contributes to the improvement of physical-mechanical properties. However, composites filled with carbon black are not able to absorb electromagnetic radiation in the given frequency range. Finally, the combination of carbon black and ferrite resulted in the modification of both physical-mechanical characteristics and absorption shielding ability of hybrid composites.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2413
Author(s):  
Mariapaola Staropoli ◽  
Vincent Rogé ◽  
Enzo Moretto ◽  
Joffrey Didierjean ◽  
Marc Michel ◽  
...  

The improvement of mechanical properties of polymer-based nanocomposites is usually obtained through a strong polymer–silica interaction. Most often, precipitated silica nanoparticles are used as filler. In this work, we study the synergetic effect occurring between dual silica-based fillers in a styrene-butadiene rubber (SBR)/polybutadiene (PBD) rubber matrix. Precipitated Highly Dispersed Silica (HDS) nanoparticles (10 nm) have been associated with spherical Stöber silica nanoparticles (250 nm) and anisotropic nano-Sepiolite. By imaging filler at nano scale through Scanning Transmission Electron Microscopy, we have shown that anisotropic fillers align only in presence of a critical amount of HDS. The dynamic mechanical analysis of rubber compounds confirms that this alignment leads to a stiffer nanocomposite when compared to Sepiolite alone. On the contrary, spherical 250 nm nanoparticles inhibit percolation network and reduce the nanocomposite stiffness.


1999 ◽  
Vol 72 (4) ◽  
pp. 721-730 ◽  
Author(s):  
G. R. Hamed ◽  
J. Zhao

Abstract Typical sulfur-cured vulcanizates of styrene-butadiene rubber (SBR) and natural rubber (NR) were prepared, and subjected to air-oven aging at 100 °C. Gum specimens exhibited an initial aging period in which stiffness was unchanged, while tensile strength and strain-to-break were significantly reduced. In contrast, black-filled vulcanizates stiffened during early aging. After intermediate aging times, NR specimens softened, while SBR stiffened. With prolonged aging, all compositions became hard and inextensible.


2009 ◽  
pp. NA-NA ◽  
Author(s):  
Shaji Joseph ◽  
P.A. Sreekumar ◽  
Jose M. Kenny ◽  
Debora Puglia ◽  
Sabu Thomas ◽  
...  

2013 ◽  
Vol 545 ◽  
pp. 211-215 ◽  
Author(s):  
Jirawat Kajornchaiyakul ◽  
Chanchira Jubsilp ◽  
Sarawut Rimdusit

-Highly filled alumina polymer composites based on bisphenol-A/aniline benzoxazine resin (BA-a) were developed. The mechanical and thermal properties of these highly filled composites at various alumina filler contents from 0 to 85 % by weight were studied by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The experimental results revealed that the storage modulus (E') at room temperature was increased from 5.93 GPa of the neat polybenzoxazine up to about 45.27 GPa of the composites with the maximum alumina content of 83 % by weight. The glass-transition temperatures (Tg) of the composites systematically increased with increasing the alumina filler contents. The Tgs of the obtained composites having alumina content ranging from 50 to 83 % by weight were found to be 178°C to 188°C, which higher that the Tg of the polybenzoxazine, i.e. 176°C implying substantial interfacial interaction between the alumina particle and the polybenzoxazine.


Author(s):  
Oleg K. Garishin ◽  
◽  
Anton Y. Beliaev ◽  

The work is devoted to the study of nanocomposites based on synthetic (styrene-butadiene) rubber with different fillers not previously used. The issue of using composites with alternative fillers is being investigated. The results of experimental testing and analysis of thermo-visco-elastic behav-ior of styrene-butadiene rubbers filled by various mineral particles of micro and nanosize, as well as pyrolysis products of organic food waste, are presented. The filled elastomers discussed in this work are mainly used in the tire industry to improve the performance of tires. All samples were tested on a dynamo-mechanical analyzer (DMA). Temperature and frequency dependences of the dynamic modulus and loss modulus are plotted for each of the composites. The frequency charac-teristics corresponded to the real range of rotation speeds of the car wheel, and the temperature var-ied from –50 to +50ºC. A comparative analysis of the results obtained was carried out. The struc-tural mechanisms of the filler are not investigated. It is assumed that the principles of operation of the investigated fillers at the structural level are similar to those described in many works for clas-sical fillers. Based on the test results a conclusion about the preferable operating conditions for the considered materials was made.


2018 ◽  
Vol 24 (5) ◽  
pp. 872-879 ◽  
Author(s):  
Nicholas Alexander Meisel ◽  
David A. Dillard ◽  
Christopher B. Williams

Purpose Material jetting approximates composite material properties through deposition of base materials in a dithered pattern. This microscale, voxel-based patterning leads to macroscale property changes, which must be understood to appropriately design for this additive manufacturing (AM) process. This paper aims to identify impacts on these composites’ viscoelastic properties due to changes in base material composition and distribution caused by incomplete dithering in small features. Design/methodology/approach Dynamic mechanical analysis (DMA) is used to measure viscoelastic properties of two base PolyJet materials and seven “digital materials”. This establishes the material design space enabled by voxel-by-voxel control. Specimens of decreasing width are tested to explore effects of feature width on dithering’s ability to approximate macroscale material properties; observed changes are correlated to multi-material distribution via an analysis of ingoing layers. Findings DMA shows storage and loss moduli of preset composites trending toward the iso-strain boundary as composition changes. An added iso-stress boundary defines the property space achievable with voxel-by-voxel control. Digital materials exhibit statistically significant changes in material properties when specimen width is under 2 mm. A quantified change in same-material droplet groupings in each composite’s voxel pattern shows that dithering requires a certain geometric size to accurately approximate macroscale properties. Originality/value This paper offers the first quantification of viscoelastic properties for digital materials with respect to material composition and identification of the composite design space enabled through voxel-by-voxel control. Additionally, it identifies a significant shift in material properties with respect to feature width due to dithering pattern changes. This establishes critical design for AM guidelines for engineers designing with digital materials.


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