scholarly journals Synergistic Effect by Polyethylene Glycol as Interfacial Modifier in Silane-Modified Silica-Reinforced Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 788
Author(s):  
Minghan Xu ◽  
Hao Xue ◽  
Wit Yee Tin ◽  
He Wang ◽  
Zhanfu Yong ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Disulfide Bonds ◽  
Silica Surface ◽  
Viscoelastic Behavior ◽  
Rolling Resistance ◽  
Peg 4000 ◽  
Silica Dispersion ◽  
Wet Grip ◽  
Positive Effect ◽  
Interfacial Modifier

The viscoelastic behavior and reinforcement mechanism of polyethylene glycol (PEG) as an interfacial modifier in green tire tread composites were investigated in this study. The results show a clear positive effect on overall performance, and it significantly improved all the parameters of the “magic triangle” properties, the abrasion resistance, wet grip and ice traction, as well as the tire rolling resistance, simultaneously. For the preparation of the compounds, two mixing steps were used, as PEG 4000 was added on the second stage in order to avoid the competing reaction between silica/PEG and silanization. Fourier transform infrared spectroscopy (FTIR) confirmed that PEG could cover the silanol groups on the silica surface, resulting in the shortening of cure times and facilitating an increase of productivity. At low content of PEG, the strength was enhanced by the improvement of silica dispersion and the slippage of PEG chains, which are chemically and physically adsorbed on silica surface, but the use of excess PEG uncombined with silica in the compound, i.e., 5 phr, increases the possibility to shield the disulfide bonds of bis(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT), and, thus, the properties were deteriorated. A constrained polymer model was proposed to explain the constrained chains of PEG in the silica-loaded composites on the basis of these results. An optimum PEG content is necessary for moderately strong matrix–filler interaction and, hence, for the enhancement in the mechanical properties.

CHARACTERIZATION OF SILICA MODIFIED WITH SILANES BY USING THERMOGRAVIMETRIC ANALYSIS COMBINED WITH INFRARED DETECTION

2018 ◽  
Vol 92 (2) ◽  
pp. 237-262 ◽  
Author(s):  
Yen Wan Ngeow ◽  
Andrew V. Chapman ◽  
Jerry Y. Y. Heng ◽  
Daryl R. Williams ◽  
Susanna Mathys ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Silica Surface ◽  
Rolling Resistance ◽  
Infrared Detection ◽  
Weight Losses ◽  
Wide Range ◽  
Similar Temperature ◽  
Silanized Silica ◽  
Wet Grip

ABSTRACT Tire treads with reduced rolling resistance and increased wet grip can be achieved by coupling hydrophilic silica to hydrocarbon rubber by using an alkoxysilane. The silica surface was modified by reaction with a wide range of coupling and non-coupling silanes. The chemistry and extent of these silanizations were elucidated using thermogravimetric analysis (TGA) combined with infrared detection. The silane grafting efficiencies were typically 52–72%, but efficiencies were lower with the bulkier 3-(di-(tridecyloxypenta(ethyleneoxy))ethoxysilyl)propyl mercaptan. However, the silica surface coverage increases with increasing size of the silane. Grafting efficiencies were lower with higher silane loadings. In the TGA, ethoxy and methoxy groups are displaced from the grafted silanes mainly at moderate temperatures (up to about 495 °C) to form siloxane bridges. Over a similar temperature range, the weaker S–S bonds present in bis(3-triethoxysilylpropyl) tetrasulfide (TESPT)- or bis[3-(triethoxysilyl)propyl] disulfide (TESPD)-modified silica are cleaved, leading to weight losses from TESPT or TESPD bound at one end to the silica and from TESPT bound at both ends. The remaining weight losses from bound silanes occurred mainly at higher temperatures. In the commercial silanized silica Coupsil 8113, TGA indicates that about two of three ethoxy groups in each triethoxysilane were lost during the silanization process.

REACTIVITY STUDY OF MERCAPTO–SILANE AND SULFIDE–SILANE WITH POLYMER

2019 ◽  
Vol 93 (2) ◽  
pp. 319-345
Author(s):  
Masaki Sato ◽  
Satoshi Mihara ◽  
Naoya Amino ◽  
Wilma K. Dierkes ◽  
Anke Blume
Keyword(s):  
Significant Influence ◽  
Rolling Resistance ◽  
Rubber Compound ◽  
Payne Effect ◽  
Polymer Reaction ◽  
Dispersion State ◽  
Mooney Viscosity ◽  
Silica Dispersion ◽  
Reactivity Study ◽  
Wet Grip

ABSTRACT Mercapto–silanes enable an improved silica dispersion state compared with sulfide–silanes in tire tread compounds, which causes a better balance of wet grip and rolling resistance. However, it also causes a higher Mooney viscosity and a shorter scorch time, which results in processing difficulties. The reason for this behavior is not clear. Because the already deeply investigated silica–silane reaction cannot explain the observed effects, the silane–polymer reaction was considered to be responsible and therefore has been evaluated in depth. The reaction between mercapto–silane or sulfide–silane and an olefin instead of a rubber was investigated in terms of reaction possibilities, mechanism, and kinetic aspects by varying the structure of the olefin. The results reveal that mercapto–silanes and sulfide–silanes affect olefins in different ways depending on the structure of the olefin. These results were compared with those in actual tire tread compounds in terms of the in-rubber properties such as the Payne effect and Mooney viscosity. It was confirmed that the different sulfur functions of the silanes interact in a different way with the polymer, which has a significant influence on the processability, silica dispersion state, and also rolling resistance indicator of the final rubber compound.

scholarly journals The Influence of Temperature and Viscosity of Polyethylene Glycol on the Rate of Microwave-Induced In Situ Amorphization of Celecoxib

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 110
Author(s):  
Nele-Johanna Hempel ◽  
Tra Dao ◽  
Matthias M. Knopp ◽  
Ragna Berthelsen ◽  
Korbinian Löbmann
Keyword(s):  
Polyethylene Glycol ◽  
Microwave Radiation ◽  
Magnesium Stearate ◽  
Einstein Equations ◽  
Dissolution Process ◽  
Target Temperature ◽  
Peg 4000 ◽  
Lower Viscosity ◽  
Model Drug

Microwaved-induced in situ amorphization of a drug in a polymer has been suggested to follow a dissolution process, with the drug dissolving into the mobile polymer at temperatures above the glass transition temperature (Tg) of the polymer. Thus, based on the Noyes–Whitney and the Stoke–Einstein equations, the temperature and the viscosity are expected to directly impact the rate and degree of drug amorphization. By investigating two different viscosity grades of polyethylene glycol (PEG), i.e., PEG 3000 and PEG 4000, and controlling the temperature of the microwave oven, it was possible to study the influence of both, temperature and viscosity, on the in situ amorphization of the model drug celecoxib (CCX) during exposure to microwave radiation. In this study, compacts containing 30 wt% CCX, 69 wt% PEG 3000 or PEG 4000 and 1 wt% lubricant (magnesium stearate) were exposed to microwave radiation at (i) a target temperature, or (ii) a target viscosity. It was found that at the target temperature, compacts containing PEG 3000 displayed a faster rate of amorphization as compared to compacts containing PEG 4000, due to the lower viscosity of PEG 3000 compared to PEG 4000. Furthermore, at the target viscosity, which was achieved by setting different temperatures for compacts containing PEG 3000 and PEG 4000, respectively, the compacts containing PEG 3000 displayed a slower rate of amorphization, due to a lower target temperature, than compacts containing PEG 4000. In conclusion, with lower viscosity of the polymer, at temperatures above its Tg, and with higher temperatures, both increasing the diffusion coefficient of the drug into the polymer, the rate of amorphization was increased allowing a faster in situ amorphization during exposure to microwave radiation. Hereby, the theory that the microwave-induced in situ amorphization process can be described as a dissolution process of the drug into the polymer, at temperatures above the Tg, is further strengthened.

Mechanical and Dynamic Properties of Silica-Filled Rubber Compounds

2013 ◽  
Vol 781-784 ◽  
pp. 475-478
Author(s):  
Watcharin Rassamee ◽  
Woothichai Thaijaroen ◽  
Thirawudh Pongprayoon
Keyword(s):  
Mechanical Properties ◽  
Dynamic Properties ◽  
Rolling Resistance ◽  
Rubber Compound ◽  
Cure Characteristics ◽  
Rubber Compounds ◽  
Silane Coupling ◽  
Unmodified Silica ◽  
Tan Δ ◽  
Wet Grip

Natural rubber compound using different silicas, including unmodified silica, admicellar-modified silica and silica with silane coupling agent, were studied. The properties including cure characteristics, mechanical properties and dynamic properties were examined with the comparison of three compounds. The results show that cure characteristics of admicellar silica/rubber compound (Ad-Si/R) was shorter than those of unmodified silica/rubber compound (Un-Si/R) and silane coupling silica/rubber compound (Sil-Si/R). Mechanical properties of Ad-Si/R and Sil-Si/R were better than those of Un-Si/R. In addition, wet grip and rolling resistance analyzed from tan δ (5 Hz) at 0°C and 60°C, respectively, by DMA were found that the wet grip of Ad-Si/R was the best, whereas the rolling resistance of Sil-Si/R was the best, in the comparison.

Isolation of Antithrombin III Without Interfering with Ethanol Fractionation System

1979 ◽  
Author(s):  
M. Wickerhauser ◽  
C. Williams
Keyword(s):  
Polyethylene Glycol ◽  
Large Scale ◽  
Antithrombin Iii ◽  
Plasma Fraction ◽  
Peg 4000 ◽  
At Iii ◽  
Elution Step ◽  
Final Purification

We described previously the isolation of antithrombin III (AT III) from the 20% polyethylene glycol (PEG 4000) supernatant of plasma or of Cohn Fraction IV-1 (Vox Sang., in press). The first of these two methods gives good recoveries of AT III but cannot be integrated with the conventional ethanol fractionation system due to the presence of PEG in the remaining plasma fraction, while Cohn Fr action IV-1, a byproduct of routine fractionation, is a poor source of AT III in terms of yield. Our modified’method involves batchwise adsorption of AT III from plasma (cryosup-ernatant) with heparin-Sepharose, using one volume of gel for each 50 volumes of plasma. The unadsorbed plasma can be used for ethanol fractionation. The AT III eluate is further purified by precipitation of some impurities including HB Ag, if present, with 20% PEG. Final purification of AT III and removal of PEG is achieved by a second adsorption-elution step on heparin-Sepharose. This method is economical and suitable for large scale application. Recovery of a highly purified AT III was 25%.

scholarly journals Silica-Reinforced Natural Rubber: Synergistic Effects by Addition of Small Amounts of Secondary Fillers to Silica-Reinforced Natural Rubber Tire Tread Compounds

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Sattayanurak ◽  
J. W. M. Noordermeer ◽  
K. Sahakaro ◽  
W. Kaewsakul ◽  
W. K. Dierkes ◽  
...  
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Dynamic Properties ◽  
Synergistic Effects ◽  
Coupling Reaction ◽  
Rolling Resistance ◽  
High Specific Surface Area ◽  
Pure Silica ◽  
Rubber Compounds ◽  
Wet Grip

Modern fuel-saving tire treads are commonly reinforced by silica due to the fact that this leads to lower rolling resistance and higher wet grip compared to carbon black-filled alternatives. The introduction of secondary fillers into the silica-reinforced tread compounds, often named hybrid fillers, may have the potential to improve tire performance further. In the present work, two secondary fillers organoclay nanofiller and N134 carbon black were added to silica-based natural rubber compounds at a proportion of silica/secondary filler of 45/10 phr. The compounds were prepared with variable mixing temperatures based on the mixing procedure commonly in use for silica-filled NR systems. The results of Mooney viscosity, Payne effect, cure behavior, and mechanical properties imply that the silica hydrophobation and coupling reaction of the silane coupling agent with silica and elastomer are significantly influenced by organoclay due to an effect of its modifier: an organic ammonium derivative. This has an effect on scorch safety and cure rate. The compounds where carbon black was added as a secondary filler do not show this behavior. They give inferior filler dispersion compared to the pure silica-filled compound, attributed to an inappropriate high mixing temperature and the high specific surface area of the carbon black used. The dynamic properties indicate that there is a potential to improve wet traction and rolling resistance of a tire tread when using organoclay as secondary filler, while the combination of carbon black in silica-filled NR does not change these properties.

scholarly journals Effects of Blend Ratio and SBR Type on Properties of Carbon Black-Filled and Silica-Filled SBR/BR Tire Tread Compounds

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Chakrit Sirisinha ◽  
Wenussarin Intiya ◽  
Pram Yodjun ◽  
...  
Keyword(s):  
Carbon Black ◽  
Abrasion Resistance ◽  
Rolling Resistance ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Blend Ratio ◽  
Wet Grip ◽  
Styrene Butadiene

This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR) and butadiene rubber (BR) and SBR type (E-SBR and S-SBR) on properties of SBR/BR tire tread compounds. Influences of these parameters on properties of the tread compounds reinforced by 80 parts per hundred rubber (phr) of carbon black (CB) and silica were also compared. Results reveal that hardness, strengths, and wet grip efficiency were impaired whereas rolling resistance was improved with increasing BR proportion. Surprisingly, the presence of BR imparted poorer abrasion resistance in most systems, except for the CB-filled E-SBR system in which an enhanced abrasion resistance was observed. Obviously, S-SBR gave superior properties (tire performance) compared to E-SBR, particularly obvious in the silica-filled system. Compared with CB, silica gave comparable strengths, better wet grip efficiency, and lower rolling resistance. Carbon black, however, offered greater abrasion resistance than silica.

Enhancement of Light-induced Nucleation of Lysozyme in the Presence of Polyethylene Glycol (PEG) 4000

2007 ◽  
Vol 36 (2) ◽  
pp. 338-339 ◽  
Author(s):  
Tetsuo Okutsu ◽  
Masaki Sato ◽  
Kenji Furuta ◽  
Yuko Fujinaga ◽  
Kumiko Horota ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Peg 4000
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