Optimization of Silane-Silica OTR Compounds. Part 1: Variations of Mixing Temperature and Time during the Modification of Silica with Bis-(3-Triethoxisilylpropyl)-Tetrasulfide

1982 ◽  
Vol 55 (4) ◽  
pp. 967-989 ◽  
Author(s):  
S. Wolff
Keyword(s):  
Reaction Time ◽  
Natural Rubber ◽  
Reaction Temperature ◽  
Thermal Reaction ◽  
Cure Rate ◽  
Mixing Conditions ◽  
Optimum Reaction ◽  
And Performance ◽  
Increasing Temperature

Abstract This study of the TESPT modification reaction of silicas gives the compounder new and valuable information about rubber filler-silane interactions. It allows TESPT to be used more practically and economically. It also suggests several areas that would be interesting and worthwhile for further investigation. The conclusions based on this study are: (1) The modification reaction of silica with TESPT in situ cannot be considered as an equilibrium reaction. (2) The degree of modification increases with TESPT reaction time and temperature. Temperature has more effect than time. (3) In natural rubber, the highest and most practical modification reaction temperature is about 160°C. By performing the modification reaction between 150 and 160°C, it produces optimum cure rate and 300% modulus. Above 160°C, the thermal reaction of TESPT with natural rubber starts and reduces the sum of filler/rubber and rubber/rubber crosslinks available in the final cured rubber. (4) Up to 160°C, the number of filler/rubber and rubber/rubber crosslinks remains constant. But increasing temperature and reaction time lead to an increasing ratio of filler/rubber to rubber/rubber bonds. This improves the properties that are the most important for an OTR tread. (5) The higher the yield of filler/rubber bonds achieved by using the optimum reaction temperature and time, the less TESPT is necessary to get the desired properties. This produces better cost/performance. (6) To get the highest modification with TESPT, it should be added with the silica, to make best use of the reaction time dependency. (7) Most of the physical properties are dependent on the ratio of filler/rubber to rubber/rubber bonds and can simply be correlated to the 300% modulus of the compound. (8) The previously published standard mixing procedures' do not have to be changed with regard to the mixing sequence. However, by controlling mixing conditions, it may be possible to lower the level of TESPT and still obtain the desired improvements in compound physical and performance properties.

scholarly journals Optimization of Synthesis of Seleno-Sargassum fusiforme(Harv.) Setch. Polysaccharide by Response Surface Methodology, Its Characterization, and Antioxidant Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Sargassum Fusiforme ◽  
Synthesis Conditions ◽  
Optimum Reaction ◽  
Series Of Experiments

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.

scholarly journals Synthesis and Performance ofN-(Benzoyl) Stearic Acid Hydrazide

2012 ◽  
Vol 9 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Yan-Hua Cai ◽  
Shun-Jiang Li
Keyword(s):  
Reaction Time ◽  
Stearic Acid ◽  
Reaction Temperature ◽  
Orthogonal Experiment ◽  
Acid Hydrazide ◽  
Semiempirical Method ◽  
Molar Ratio ◽  
H Nmr ◽  
And Performance ◽  
Benzoyl Hydrazine

N-(benzoyl) stearic acid hydrazide was synthesized from benzoyl hydrazine and stearyl chloride which was deprived from stearic acid via acylation. The structure of the compound had been characterized by FT-IR,1H NMR, at the same time, the structure of N-(benzoyl) stearic acid hydrazide was optimized by the semiempirical method PM3. The influence of the reaction ratio, reaction time and reaction temperature to the yield ofN-(benzoyl) stearic acid hydrazide was investigated by orthogonal experiment, and the optimized reaction condition was molar ratio of benzoyl hydrazine: stearyl chloride 1:1, reaction time 6 h, reaction temperature 70°C, and the yield was 92.9%. The TGA thermal analysis of N-(benzoyl) stearic acid hydrazide showed that thermal stability ofN-(benzoyl) stearic acid hydrazide was affected by heating rate, and theN-(benzoyl) stearic acid hydrazide enhanced the tensile strength, modulus and elongation at break of Poly(L-lactic acid)(PLLA).

Study on Synthesis of Nitrophenyl Isocyanates Using Triphosgene

2012 ◽  
Vol 550-553 ◽  
pp. 1039-1042 ◽  
Author(s):  
Gui Rong Cao ◽  
Xue Yan Zhao ◽  
Rui Jie Xiao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Optimum Reaction

In this paper, triphosgene respectively reacting with o-nitrophenyl aniline, m-nitrophenyl aniline and p-nitrophenyl aniline to synthesize corresponding isocyanates. The effects of reactants molar ratio, reaction time and reaction temperature on the yield were investigated. As a result, using 1,2-dichloroethane as reaction solvent, the optimum molar ratio of the three kinds of nitroaniline and triphosgene were all 2.5:1, the optimum reaction time of synthesis of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate respectively was 6h, 5.5h and 5h; the optimum reaction temperature of synthesis of the three kinds of nitrophenyl isocyanates were all 75°C. Under the optimal conditions, the yield of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate could respectively be 80.3%, 83.7% and 83.5%. The products were characterized by meltingtest, ebulliometry, IR, and HPLC

Properties of Polyaniline with the Doping of Different Acid

2012 ◽  
Vol 502 ◽  
pp. 31-35 ◽  
Author(s):  
Xiao Hua Wang
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Content ◽  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Dodecylbenzenesulfonic Acid ◽  
Thermal Stability Of

Polyaniline(PANI) with the doping of hydrochloride(HC1), aminosulfonic acid (NH2SO3H) or dodecylbenzenesulfonic acid(DBSA) was prepared by in-situ polymerization. Effects of acid content, reaction time, oxidant ammonium persulfate (APS) dosage and reaction temperature on the conductivity of PANI were studied. The resistance and thermal stability of them were compared. Results show that the largest conductivity of HC1-PANI is 1.98 s.cm-1 among them in case the C(HC1)=0.5mol/L, reaction time is 6.0h, n(APS/aniline)=1.0; The conductivity of NH2SO3H-PANI is 0.2s.cm-1 in case the C(NH2SO3H)=1.0mol/L, reaction time is 6.0h, n(APS/aniline)=2.0; The conductivity of DBSA-PANI is 0.98s.cm-1 in case the C(DBSA)=1.0 mol/L, reaction time is 8.0h, n(APS/aniline) = 2.0. The the least resistance of HC1-PANI is 10Ω, and that of NH2SO3H- PANI is the largest of 120Ω. The order of their thermal stability is DBSA-PANI > NH2SO3H-PANI > HC1-PANI before 350°C, that of their thermal stability is inverse when it reaches 350°C.

CHLORINATION REACTION KINETICS OF THE LOW-CONCENTRATION NATURAL RUBBER LATEX

2013 ◽  
Vol 86 (4) ◽  
pp. 604-614 ◽  
Author(s):  
Lanzhen He ◽  
Jieping Zhong ◽  
Jing Chen ◽  
Chenpen Li ◽  
Linxue Kong ◽  
...  
Keyword(s):  
Reaction Time ◽  
Natural Rubber ◽  
Reaction Temperature ◽  
High Speed ◽  
Kinetic Constant ◽  
Natural Rubber Latex ◽  
Chlorination Reaction ◽  
Rubber Latex ◽  
Low Concentration ◽  
Kinetics Of

ABSTRACT The kinetics of the chlorination of low-concentration natural rubber latex was investigated. The kinetic data were derived from chlorine concentrations in chlorinated natural rubber (CNR) for different reaction times and temperatures. The chlorination reaction process can be divided into two stages—a high-speed period (stage 1) and a low-speed period (stage 2)—using the graphed curves of the change in chlorine content with change in reaction time. The relationship of the chlorination conversion ratio x to reaction time t and temperature T can be expressed as x = 1.15 − 0.916e−kt, where the kinetic constant k = 0.00907 + 6.39 × 10−6e0.0211T. The overall apparent reaction order n for the first stage is 4.8, whereas for the second stage it is 1.0, using kinetic fitting. The apparent activation energy Ea was calculated, using the Arrhenius equation, to be 5.32 kJ/mol for stage 2. The lower value of Ea suggests that the chlorination rate is less sensitive to reaction temperature in this stage. The chlorination reaction rate increases with the increase in reaction temperature during stage 2, but the effects are not visible. However, a temperature that is too high may result in energy being wasted. We conclude that the proper reaction temperature in stage 2, taking the kinetic effects into account, is between 323.15 and 353.15 K.

Study on Catalytic Degradation of Diesel Pollution in Seawater by Laccase

2013 ◽  
Vol 781-784 ◽  
pp. 2324-2327
Author(s):  
Xu Zheng ◽  
Xiao Cai Yu ◽  
Yun Qing Liu ◽  
Xiao Xv ◽  
Jin Fang Chen
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Sea Water ◽  
Oil Pollution ◽  
Ph Value ◽  
Degradation Process ◽  
Catalytic Degradation ◽  
Initial Concentration ◽  
Optimization Study ◽  
Optimum Reaction

Sea water joining diesel was selected to prepare simulated marine oil pollution. With the target of removing diesel from seawater, the influence of various factors on the laccase-catalyzed degradation process was discussed. The experimental results show that the laccase-catalyzed degradation process was significantly affected by laccase dosage, reaction temperature, reaction time, pH of the solution and initial concentration of diesel in the oily wastewater. A systematic optimization study was carried out through a orthogonal test on the basis of the results of the single-factor experiments,and the optimum reaction conditions of laccase catalytic degradation diesel pollutants in seawater was determined. The results indicate that under the conditions of diesel initial concentration of 0.1g/L, laccase dosage of 8mg/L, pH value of 6, the reaction temperature of 25°C and the reaction time of 4h, laccase catalytic degradation rate of diesel pollution can be up to 63.85%.

The Preparation Technique of Nanometer Molybdenum Trioxide by Hydrothermal Synthesis

2011 ◽  
Vol 117-119 ◽  
pp. 807-810
Author(s):  
Ji Wen Li ◽  
Yan Hua Ma ◽  
Fang Fang Gong ◽  
Guo Shang Zhang ◽  
Liu Jie Xu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
Molybdenum Trioxide ◽  
Ph Value ◽  
Ultrafine Particle ◽  
Preparation Technique ◽  
Optimum Ph ◽  
Optimum Reaction ◽  
Optimal Reaction

The technique of hydrothermal synthesis is used to prepare nanometer molybdenum trioxide through controlling the parameters such as the acidification condition, the reaction temperature, the reaction time and so on. The technique is under high temperature and high pressure by water as the solvent. Synthesized molybdenum trioxide powder is characterized by XRD, SEM, and HRTEM. The optimal reaction time is 40h, the optimum reaction temperature is 170°C, and the optimum pH value is 1.0. The results indicate that powder has an ultrafine particle size, high purity, and narrow size distribution, good fluidity, light agglomerate and is perfect in crystal.

Biodiesel Production through Direct Transesterification of Waste Cooking Oil with Alcohol via Ultrasonic Wave

2013 ◽  
Vol 389 ◽  
pp. 12-16
Author(s):  
Yong Feng Kang ◽  
Hua Jin Shi ◽  
Lin Ge Yang ◽  
Jun Xia Kang ◽  
Zi Qi Zhao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Ultrasonic Power ◽  
Cooking Oil ◽  
Biodiesel Synthesis ◽  
Optimum Reaction ◽  
Ester Exchange Reaction

Biodiesel is prepared from waste cooking oil and methanol. The ester exchange reaction is conducted under ultrasonic conditions with alkali as the catalysts. Five factors influencing on the transesterification reaction of biodiesel production are discussed in this study, including the reaction time, reaction temperature, catalyst amount, methanol to oil molar ratio, ultrasonic power. A series of laboratory experiments were carried out to test the conversion of biodiesel under various conditions. The process of biodiesel production was optimized by application of orthogonal test obtain the optimum conditions for biodiesel synthesis. The results showed that the optimum reaction conditions were:molar ratio of oil to methanol 8:1,catalysts 1.2g KOH/100g oil,reaction temperature 70°C, reaction time 50 min,Ultrasonic power 400W. The conversion may up to 96.48%.

scholarly journals In situ trans-esterification of oil-containing Jatropha curcas seeds to produce biodiesel fuel

2018 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
I Amalia Kartika ◽  
M Yani ◽  
D Ariono ◽  
Ph Evon ◽  
L Rigal
Keyword(s):  
Reaction Time ◽  
Acid Value ◽  
Biodiesel Fuel ◽  
Direct Production ◽  
Yield And Quality ◽  
Optimum Reaction ◽  
Biodiesel Quality ◽  
Jatropha Seed

The objective of this study was to investigate in situ trans-esterification allowing direct production biodiesel from jatropha seed. The influences of amount of KOH catalyst, methanol to seed ratio, amount of n-hexane to methanol and seed ratio, stirring speed, temperature and reaction time were examined to define the best performance of biodiesel yield and quality. Generally, methanol to seed ratio, amount of KOH and n-hexane to methanol and seed ratio affected biodiesel yield. An increase of biodiesel yield was observed as methanol to seed ratio, amount of KOH and n-hexane to methanol and seed ratio were increased. Stirring speed, temperature and reaction time did not affected biodiesel yield. Highest biodiesel yield (89%) was obtained under 6:1 methanol to seed ratio, 0.075 mole/L KOH in methanol, 3:3:1 n-hexane to methanol and seed ratio, 600 rpm stirring speed, 40 °C temperature and 6 h reaction time. The effect of process parameters on biodiesel quality was less important. In all experiments tested, the biodiesel quality was very good (acid value < 0.3 mg of KOH/g, viscosity < 5.5 cSt, saponification value > 183 mg of KOH/g). The quality of biodiesel produced under optimum reaction condition was in accordance with the Indonesian Biodiesel Standard. Keywords: biodiesel, in situ, jatropha seed, transesterificationAbstrakPenelitian ini bertujuan untuk memproduksi biodiesel secara langsung dari biji jarak pagar melalui proses transesterifikasi in situ. Parameter proses yang dipelajari adalah pengaruh konsentrasi katalis KOH, rasio metanol terhadap bahan, rasio n-heksan terhadap metanol dan bahan, kecepatan pengadukan, suhu dan waktu reaksi terhadap rendemen biodiesel dan kualitasnya. Rasio metanol terhadap bahan, konsentrasi KOH dan rasio n-heksan terhadap metanol dan bahan berpengaruh nyata terhadap rendemen biodiesel. Semakin tinggi rasio metanol terhadap bahan, konsentrasi KOH dan rasio n-heksan terhadap metanol dan bahan, rendemen biodiesel semakin meningkat. Kecepatan pengadukan, suhu dan waktu reaksi tidak berpengaruh nyata terhadap rendemen biodiesel. Rendemen biodiesel tertinggi (89%) diperoleh dari perlakuan rasio metanol terhadap bahan 6:1, 0.075 mol/L KOH dalam metanol, rasio n-heksan terhadap metanol dan bahan 3:3:1, kecepatan pengadukan 600 rpm, suhu 40 °C dan waktu reaksi 6 jam. Kualitas biodiesel yang dihasilkan dari proses transesterifikasi in situ biji jarak pagar pada seluruh perlakuan yang diuji sangat baik (bilangan asam < 0.3 mg KOH/g, viskositas < 5.5 cSt, bilangan penyabunan > 183 mg KOH/g), dan tidak dipengaruhi oleh parameter-parameter proses. Kualitas biodiesel yang dihasilkan dari kondisi proses optimum memenuhi Standar Biodiesel Indonesia.Kata kunci: biodiesel, in situ, biji jarak, transesterifikasi

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