scholarly journals Nitroxide-Mediated Copolymerization of Itaconate Esters with Styrene

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 254 ◽  
Author(s):  
Sepehr Kardan ◽  
Omar Garcia Valdez ◽  
Adrien Métafiot ◽  
Milan Maric
Keyword(s):  
Chain Transfer ◽  
Average Molecular Weight ◽  
Transfer Reactions ◽  
Dioxane Solution ◽  
Number Average Molecular Weight ◽  
First Order ◽  
First Order Kinetics ◽  
The Poor ◽  
Stable Adduct ◽  
Nitroxide Mediated Polymerization

Replacing petro-based materials with renewably sourced ones has clearly been applied to polymers, such as those derived from itaconic acid (IA) and its derivatives. Di-n-butyl itaconate (DBI) was (co)polymerized via nitroxide mediated polymerization (NMP) to impart elastomeric (rubber) properties. Homopolymerization of DBI by NMP was not possible, due to a stable adduct being formed. However, DBI/styrene (S) copolymerization by NMP at various initial molar feed compositions fDBI,0 was polymerizable at different reaction temperatures (70–110 °C) in 1,4 dioxane solution. DBI/S copolymerizations largely obeyed first order kinetics for initial DBI compositions of 10% to 80%. Number-average molecular weight (Mn) versus conversion for various DBI/S copolymerizations however showed significant deviations from the theoretical Mn as a result of chain transfer reactions (that are more likely to occur at high temperatures) and/or the poor reactivity of DBI via an NMP mechanism. In order to suppress possible intramolecular chain transfer reactions, the copolymerization was performed at 70 °C and for a longer time (72 h) with fDBI,0 = 50%–80%, and some slight improvements regarding the dispersity (Ð = 1.3–1.5), chain activity and conversion (~50%) were observed for the less DBI-rich compositions. The statistical copolymers produced showed a depression in Tg relative to poly(styrene) homopolymer, indicating the effect of DBI incorporation.

ATRP of MMA initiated by 2-bromoisobutyric acid 4-(2- benzothiazole-2-yl-vinyl)-phenyl ester (BPBVE) and its fluorescent property in the presence of metal ions

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Pei-Yang Gu ◽  
Qing-Feng Xu ◽  
Jian-Feng Ge ◽  
Zhang Liang ◽  
Jian-Mei Lu ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Linear Increase ◽  
Number Average Molecular Weight ◽  
Phenyl Ester ◽  
Strong Emission ◽  
First Order ◽  
First Order Kinetics ◽  
Light Area ◽  
End Group

Abstract2-Bromoisobutyric acid 4-(2-benzothiazole-2-yl-vinyl)-phenyl ester (BPBVE) was used for the heterogeneous atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) with a copper(I)bromide/2,2’-bipyridine catalytic system. Factors such as the reaction temperature and mole ratio of catalyst to initiator, which could affect the ATRP system, were discussed in the paper. The functional end group was characterized via UV-vis and 1H NMR spectroscopy. The rates of polymerizations exhibited first-order kinetics with respect to the monomer, and a linear increase in the number-average molecular weight with increasing monomer conversion was observed for these initiation systems. The polydispersity indices (PDI) of the polymer were relatively low (1.07- 1.23) up to high conversions. This PMMA with BPBVE as end group shows strong emission at blue-light area whether in solution or in solid. In particularly, emission was decreased (or quenched) with appearance of metal cations (Zn2+, Co2+, Ni2+, Pb2+, Mn2+, Cu2+, Fe3+, Ag+) in DMF solution.

TERTIARY MERCAPTANS AS MODIFIERS IN GR-S POLYMERIZATIONS

1947 ◽  
Vol 25b (2) ◽  
pp. 159-182 ◽  
Author(s):  
Maurice Morton ◽  
R. V. V. Nicholls
Keyword(s):  
Molecular Weight ◽  
Rate Equation ◽  
Slow Rate ◽  
Chain Transfer ◽  
Transfer Reactions ◽  
Molecular Weight Polymer ◽  
First Order ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Order Rate Equation

Tertiary octyl, decyl, dodecyl, and hexadecyl mercaptans were investigated as modifiers in GR-S polymerizations.The rate of disappearance of these modifiers followed a first-order rate equation during the first half of the polymerization, in accordance with the theory of chain-transfer reactions. During the latter part of the reaction, an increased rate of disappearance generally occurred. A mechanism is suggested.The rate of disappearance increased with decreasing chain-length of the mercaptan. The intrinsic viscosities and molecular weight distributions of the polymers obtained at different conversions were related to the activity of each mercaptan as a modifier. Values for the regulating index of each mercaptan were calculated.The slow rate of disappearance of tertiary hexadecyl mercaptan leads to the formation of polymer that is relatively homogeneous in molecular weight, and this mercaptan is therefore a desirable modifier. However, after 50% polymerization, the regulator action shows a marked acceleration, leading to the formation of progressively lower molecular weight polymer and resulting in a spread in the molecular weight distribution.

scholarly journals Synthesis of Poly(methyl methacrylate) Grafted Multiwalled Carbon Nanotubes via a Combination of RAFT and Alkyne-Azide Click Reaction

2019 ◽  
Vol 9 (3) ◽  
pp. 603 ◽  
Author(s):  
Wenzhong Ma ◽  
Yuchen Zhao ◽  
Zhiwei Zhu ◽  
Lingxiang Guo ◽  
Zheng Cao ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Click Reaction ◽  
Multiwalled Carbon ◽  
Poly Methyl Methacrylate ◽  
First Order ◽  
Pristine Mwcnts ◽  
First Order Kinetics ◽  
Molecular Weight Dependence ◽  
Reversible Addition

An efficient synthesis route was developed for the preparation of multiwalled carbon nanotube (MWCNT) nanohybrids using azide-terminated poly(methyl methacrylate) (PMMA) via a combination of reversible addition fragmentation chain transfer (RAFT) and the click reaction. A novel azido-functionalized chain transfer agent (DMP-N3) was prepared and subsequently employed to mediate the RAFT polymerizations of methyl methacrylate (MMA). The RAFT polymerizations exhibited first-order kinetics and a linear molecular weight dependence with the conversion. The kinetic results show that the grafting percentage of PMMA on the MWCNTs surface grows along with the increase of the reaction time. Even at 50 °C, the grafting rate of azide-terminated PMMA is comparatively fast in the course of the click reaction, with the alkyne groups adhered to MWCNTs in less than 24 h. The successful functionalization of PMMA onto MWCNT was proved by FTIR, while TGA was employed to calculate the grafting degree of PMMA chains (the highest GP = 21.9%). Compared with the pristine MWCNTs, a thicker diameter of the MWCNTs-g-PMMA was observed by TEM, which confirmed the grafted PMMA chain to the surface of nanotubes. Therefore, the MWCNTs-g-PMMA could be dispersed and stably suspended in water.

Nitroxide-mediated polymerization of styrene in the presence of a novel trinitroxide

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Jieai Li ◽  
Zhengbiao Zhang ◽  
Xiulin Zhu ◽  
Jian Zhu ◽  
Zhenping Cheng
Keyword(s):  
Molecular Weight ◽  
Ascorbic Acid ◽  
Linear Structure ◽  
Controlled Polymerization ◽  
First Order ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
First Order Kinetics ◽  
Weight Distributions ◽  
Nitroxide Mediated Polymerization

AbstractThe bulk polymerizations of styrene were performed in the presence of a novel trinitroxide, 2,4,6-tri(4’-oxy-2’,2’,6’,6’-tetramethyl-1’-piperidinyloxy)-1,3,5- triazine (TTPT). Typical features of controlled polymerization were observed, such as the first-order kinetics, the molecular weights (Mn) linearly increased with the conversion, and relatively narrow molecular weight distributions (Mw/Mn). The 1H NMR was used to characterize the obtained polystyrene. The most of obtained polymers at 110 °C were the polymer with two-arm linear structure, not the expected three-arm structure, which was confirmed by the analysis of degradation of obtained polymer by ascorbic acid. A proposed polymerization route of styrene mediated by TTPT was also discussed.

THE KINETICS OF THE INHIBITED AUTOXIDATION OF TETRALIN

1964 ◽  
Vol 42 (10) ◽  
pp. 2324-2333 ◽  
Author(s):  
J. A. Howard ◽  
K. U. Ingold
Keyword(s):  
Isotope Effect ◽  
Chain Transfer ◽  
Square Root ◽  
Deuterium Isotope Effect ◽  
First Order ◽  
Oxidation Rates ◽  
First Order Kinetics ◽  
A Value ◽  
Root Relation ◽  
Kinetics Of

The kinetics of the inhibition of the autoxidation of tetralin by 2,6-di-t-butyl-4-methylphenol, phenol, and 4-methoxyphenol have been investigated at 65 °C. The highly hindered 2,6-di-t-butyl-4-methylphenol follows simple first order kinetics and exhibits a normal deuterium isotope effect (kH/kD = 10). The kinetics with phenol are complicated by the fact that the phenoxy radical can abstract a hydrogen atom from both tetralin and its hydroperoxide. This leads to oxidation rates which are inversely proportional to the square root of the phenol concentration. The deuterium isotope effect has about the value to be expected in view of this square root relation. The kinetics with 4-methoxyphenol result from chain transfer and from chain termination by the coupling of 4-methoxyphenoxy radicals. The isotope effect varies between zero and a value that approaches the upper limit of about 10 at low inhibitor concentrations.

Functional Chain Transfer Agent and its Application in Block Polymer Synthesis

2015 ◽  
Vol 799-800 ◽  
pp. 475-478
Author(s):  
Xiao Quan Peng ◽  
Chun Ju He
Keyword(s):  
Block Copolymer ◽  
Triblock Copolymer ◽  
Chain Transfer ◽  
Phase Transfer ◽  
Triblock Copolymers ◽  
Reaction System ◽  
Block Polymer ◽  
First Order ◽  
First Order Kinetics ◽  
Raft Agent

In this report, s-1-dodecyl-s’-(α,α’-dimethyl-α’’-dimethyl-α’’-aceticacid) trithiocarbonate (RAFT-COOH) was successfully synthesized by phase transfer catalyst reaction, which was then amidated with diaminopropyl terminated polydimethylsiloxane (NH2-PDMS-NH2) to synthesize PDMS-based macro-RAFT agent to control the synthesis of tri-block copolymer PDMA-b-PDMS-b-PDMA. The successful synthesis of small and macro chain transfer has been confirmed by techniques of FTIR. Moreover, the polymerization to synthesize tri-block copolymer proceeded with first-order kinetics, which showed the reaction system was a controlled/‘living’ polymerization. The triblock copolymers have also been characterized by FTIR, 1HNMR, and GPC techniques, which confirmed the successful synthesis of triblock copolymer.

Studies of vinyl ester resins and their urethanized derivatives

1993 ◽  
Vol 5 (3) ◽  
pp. 207-212 ◽  
Author(s):  
R R Pachha ◽  
J R Thakkar ◽  
R D Patel
Keyword(s):  
Vinyl Ester ◽  
Epoxy Resins ◽  
Average Molecular Weight ◽  
Diglycidyl Ether ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
First Order ◽  
First Order Kinetics ◽  
Amino Phenol ◽  
Vinyl Ester Resins

The epoxy resins diglycidyl ether of bisphenol A and triglycidyl p-amino phenol were reacted with acrylic acid to afford the corresponding acrylated resins. These vinyl ester resins were then reacted with toluene di-isocyanate to procure their urethanized derivatives. All these resins were characterized by their viscosity, number average molecular weight and infrared spectrophotometry. Curingconditions for these resins were established by differential scanning calorimetry. The results indicated that the curing reaction follows first-order kinetics, with activation energy in the range 53-84 kJ mol-. Styrene monomer was observed to lower the curing temperature of all resin systems when incorporated prior to curing.

Photo-catalytic degradation of gaseous pollutants in paper mills of southern China

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen
Keyword(s):  
Degradation Rate ◽  
Southern China ◽  
Catalytic Degradation ◽  
Pulp And Paper ◽  
Gaseous Pollutants ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

Kinetic of oxidation of methyl orange by vanadium(V) under conditions VO2+ and decavanadates coexist: Catalysis by Triton X-100 micellar medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methyl Orange ◽  
Solution Ph ◽  
Vanadium Concentration ◽  
Limiting Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetic Pattern ◽  
Triton X ◽  
Kinetics Of

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.

Biodegradation rates of aromatic contaminants in biofilm reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Jean-Pierre Arcangeli ◽  
Erik Arvin
Keyword(s):  
Aromatic Hydrocarbons ◽  
Competitive Inhibition ◽  
Removal Rate ◽  
First Order ◽  
Biofilm Reactors ◽  
First Order Kinetics ◽  
Reducing Conditions ◽  
Low Concentrations ◽  
Degradation Rates ◽  
Order Surface

This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols, chlorophenols, nitrophenol, chlorobenzenes and aromatic nitrogen-, sulphur- or oxygen-containing heterocyclic compounds (NSO-compounds). Furthermore, a comparison with degradation rates observed for easily degradable organics is also presented. At concentrations below 20-100 μg/l the degradation of the aromatic compounds was typically controlled by first order kinetics. The first-order surface removal rate constants were surprisingly similar, ranging from 2 to 4 m/d. It appears that NSO-compounds inhibit the degradation of aromatic hydrocarbons, even at very low concentrations of NSO-compounds. Under nitrate-reducing conditions, toluene was easily biodegraded. The xylenes and ethylbenzene were degraded cometabolically if toluene was used as a primary carbon source; their removal was influenced by competitive inhibition with toluene. These interaction phenomena are discussed in this paper and a kinetic model taking into account cometabolism and competitive inhibition is proposed.

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