Research of Atom Transfer Radical Polymerization of Methyl Polypropylene

2016 ◽  
Vol 852 ◽  
pp. 720-725
Author(s):  
Yu Qing Xu ◽  
Yong Ke ◽  
Xiao Yong Hu ◽  
Jin Cui ◽  
Zhi Yuan Lin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Dispersion Coefficient ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
Polymerization Reaction ◽  
Polymer Dispersion ◽  
Precise Control ◽  
Copper Bromide ◽  
Relative Molecular Weight

The methyl polypropylene was prepared bsaed on toluene as solvent, cuprous bromide (CuBr) / copper bromide (CuBr2)/tris (2-dimethylaminoethyl) amine (Me6TREN) as catalyst, azo dimethoxyisoquinolin heptanenitrile (V-70) as radical additive, 2-bromoisobutyrate (EtBiB) as initiator. The polymerization reaction was initiated by using the ultimate atomic radical polymerization (UATRPSM), whose chain reaction was manifested in linear first-order kinetics. In this study, the conversion of monomers, polymer dispersion coefficient and the relative molecular weight with monomer conversion rate changes were studied by gas chromatography (GC) and gel permeation chromatography (GPC). The results show that the final monomer conversion was 87%; with increasing monomer conversion, polymer dispersion coefficient (PDI) decreases and reaches the optimum value 1.19, while the relative molecular weight of the linear growth, and prove the reaction was precise control.

Reverse Atom Transfer Radical Polymerization of N-Vinylpyrrolidone in Bulk Catalyzed by AIBN)/FeCl3/ PPh3

2013 ◽  
Vol 295-298 ◽  
pp. 3-7
Author(s):  
Guo Bin Yi ◽  
Ying Wu ◽  
Ping Ke Ai
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
13C Nmr Spectroscopy ◽  
Atom Transfer ◽  
First Order Kinetics

The reverse atom transfer radical polymerization (RATRP) of N-vinylpyrrolidone (NVP) using azobisisobutyronitrile (AIBN)/FeCl3/triphenylphosphine(PPh3) as the initiating system, was successfully carried out in bulk at 80°C. Plots of In ([M]0/[M]) vs time and molecular weight evolution vs monomer conversion presented a linear dependence and the polymerization was proved to accord with the first-order kinetics. After 10 hours’ reaction, the monomer conversion was up to 84%. Gel permeation chromatography (GPC) was used in testing the molecular weight of polymer and molecular weight distribution, the results showed that polymer molecular weight distribution was as low as 1.018 (Mn=3288 g/mol). Moreover, the resultant polymer was characterized by 1H-NMR, 13C-NMR spectroscopy and Pyrolysis GC-MS, and the results showed that the polymerization mechanism is consistent with RATRP.

The Research of Silane Oligomer with Lower Valatilization Rate for Protecting Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1318-1322 ◽  
Author(s):  
Hong Yao Sun ◽  
Zheng Yang ◽  
Gao Xia Sun ◽  
Xue Feng Xu
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Chloride Ions ◽  
Polymerization Reaction ◽  
Low Molecular Weight ◽  
Construction Process ◽  
Reaction Conditions ◽  
Hydrophobic Agent ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

As one of the measures to improve the durability of concrete, silane penetrating hydrophobic agents can preserve the properties of respiratory function of concrete and can prevent the penetration from harmful medium such as chloride ions. Because of low molecular weight of the silane penetrating hydrophobic agent such as isobutyl triethoxysilane, high volatilization rate of silane can result in waste of material in construction process. The silane oligomer was obtained by radical polymerization reaction with suitable monomers, initiators and reaction conditions. Furthermore, we verified the structure of the silane oligomer by FT-IR spectroscopy and got its molecular weight by GPC(Gel Permeation Chromatography). The silane oligomer with lower volatilization rate has excellent properties of hydrophobicity, higher penetration depth and resistance to chloride ions penetration.

Efficient synthesis of narrowly dispersed amphiphilic double-brush copolymers through the polymerization reaction of macromonomer micelle emulsifiers at the oil–water interface

2016 ◽  
Vol 7 (27) ◽  
pp. 4476-4485 ◽  
Author(s):  
Heng Li ◽  
Han Miao ◽  
Yong Gao ◽  
Huaming Li ◽  
Daoyong Chen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Radical Polymerization ◽  
Pickering Emulsion ◽  
Polymerization Reaction ◽  
Water Interface ◽  
Efficient Synthesis ◽  
Oil Water

Narrowly dispersed amphiphilic PMA-g-PMMA/PDMA DBCs with high molecular weight were efficiently synthesized by Pickering emulsion template directed radical polymerization of macromonomer micelles.

Synthesis of poly-2-hydroxyethyl methacrylate–montmorillonite nanocomposite via in situ atom transfer radical polymerization

2008 ◽  
Vol 23 (12) ◽  
pp. 3316-3322 ◽  
Author(s):  
Ayhan Oral ◽  
Talal Shahwan ◽  
Çetin Güler
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Interlayer Spacing ◽  
Solvent System ◽  
Polymerization Reaction ◽  
Atom Transfer ◽  
Scanning Calorimetry ◽  
Copper Bromide ◽  
Transmission Electron

The poly-2-hyroxyethyl methacrylate (PHEMA)/clay nanocomposite was synthesized by in situ atom transfer radical polymerization (ATRP) from initiator moieties immobilized within the silicate galleries of the clay particles. To produce organically modified montmorillonite (MMT) that has ATRP initiator moiety, a new catalyst that consists of quaternary ammonium salt moiety and an initiator moiety was synthesized. This initiator was intercalated into the interlayer spacing of the MMT. The polymerization reaction was carried out in a mixed solvent system consisting of methyl ethyl ketone and 1-propanol at 50 °C, using the initiator that has been already synthesized with a copper bromide catalyst. The 2, 2′-bipyridyl (bpy) complex was used as ligand. The products were characterized via Fourier transform infrared, nuclear magnetic resonance (1H NMR, 12C NMR), transmission electron microscopy, x-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry.

Living free radical polymerization of styrene with 2-cyanoprop-2-yl dithionaphthalate as RAFT agent

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhu Jian ◽  
Zhu Xiulin ◽  
Zhou Di ◽  
Chen Jianying
Keyword(s):  
Molecular Weight ◽  
Reaction Temperature ◽  
Raft Polymerization ◽  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
Bulk Polymerization ◽  
Polymerization Rate ◽  
Chain Extension ◽  
Raft Agent

Abstract The reversible addition-fragmentation chain transfer (RAFT) bulk polymerization of styrene was studied using 2-cyanoprop-2-yl dithionaphthalate (CPDN) as RAFT agent in the presence or absence of 2,2’-azoisobutyronitrile (AIBN). The results of both thermally and AIBN-initiated styrene (St) polymerizations show that St can be polymerized in a controlled way using CPDN as RAFT agent; i.e., the polymerization rate is first order with respect to monomer concentration, and molecular weight increases linearly with monomer conversion. The molecular weights obtained from gel permeation chromatography are close to the theoretical values and molecular weight distributions are relatively narrow (Mw/Mn < 1.2). It is confirmed by chain extension reaction that the polymer prepared via RAFT polymerization can be used as a macroRAFT agent. The effects of reaction temperature and mole ratios [St]0/[CPDN]0/[AIBN]0 on the polymerization were investigated. The results indicate that the reaction temperature has a positive effect on the polymerization rate, but little effect on molecular weight and molecular weight distribution, and the optimum mole ratios were found to be [CPDN]0/[AIBN]0 > 4/3 and [St]0/[CPDN]0 < 800.

Effects of the Carboxyl Density on the Properties of Polycarboxylate-Type Superplasticizer

2014 ◽  
Vol 989-994 ◽  
pp. 151-155
Author(s):  
Cheng Fei Fu ◽  
Guang Jun Zheng ◽  
Kang Ling Li ◽  
Yao Bi ◽  
Long Xiong
Keyword(s):  
Molecular Weight ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Acrylic Acid ◽  
Weight Distribution ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
Cement Pastes ◽  
Gel Permeation

The effect of carboxyl density (the ratio of acrylic acid and polyoxyethylene ether) upon the performance, molecular weight, and monomer conversion rate of polycarboxylate (PCE) were investigated by slump test, Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC), respectively. The results showed that with carboxyl density increased from 2:1 to 7:1, molecular weight of PCE increased from 7968.5 to 13930.1 and the molecular weight distribution coefficient increased from 1.5 to 2. The HPLC date indicated carboxyl density does not affect the rate of monomer conversion. Test of the fluidity of cement pastes displayed that as carboxyl density was 4.0:1, PCE show the optimal dispersion and dispersion-retaining ability.

Atom transfer radical polymerization of styrene initiated by the novel initiator 2-bromo-2-nitropropane

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Gang Wang ◽  
Xiulin Zhu ◽  
Cheng Zhengping ◽  
Jian Zhu
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Catalyst System ◽  
Chain Extension ◽  
Atom Transfer ◽  
The Novel ◽  
H Nmr

AbstractHeterogeneous atom transfer radical polymerization (ATRP) of styrene initiated by 2-bromo-2-nitropropane in bulk was carried out with CuCl/2,2′-bipyridine as the catalyst. The kinetics was first order in monomer and the numberaverage molecular weight of the polymer increased linearly with monomer conversion, indicating the ‘living’/controlled nature of the polymerization. However, the number-average molecular weight was usually higher than the theoretical one. The nitro group might react with the Cu complex, resulting in insufficient initiation. The amount of catalyst has no effect on the controllability of this catalyst system for the ATRP of styrene. The presence of a halide end group in the obtained polymer was confirmed by both 1H NMR and chain-extension reaction.

scholarly journals In Situ Surface-Initiated Atom-Transfer Radical Polymerization Utilizing the Nonvolatile Nature of Ionic Liquids: A First Attempt

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Ryo Satoh ◽  
Saika Honma ◽  
Hiroyuki Arafune ◽  
Ryo Shomura ◽  
Toshio Kamijo ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Film ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Silicon Wafer ◽  
Thin Liquid Film ◽  
Average Molecular Weight ◽  
Polymerization Reaction ◽  
Atom Transfer

In this paper, in situ surface-initiated atom-transfer radical polymerization (SI-ATRP) based on both an open and a coated system, without using volatile reagents, was developed to overcome the limited usage of ATRP due to the necessity of sealing. Nonvolatile ionic liquid (IL)-type components were used, specifically N,N-diethyl-N-(2-methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide as the polymerizable monomer and N,N-diethylmethyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide as the polymerization solvent. In the experiment, the reversible-deactivation radical polymerization characteristics are properly ensured in nonvolatile ATRP solution coated on silicon wafer as thin liquid film, to form concentrated polymer brushes (CPBs). The average molecular weight and molecular-weight distribution of the polymer produced in the liquid film and formed on silicon wafer were measured by gel permeation chromatography, which confirms that the polymerization reaction occurred as designed. Furthermore, it is clarified that the surface of the polymer brush synthesized in situ swollen by IL also exhibited low friction characteristics, comparable to that synthesized in a typical immersion process. This paper is the first to establish the effectiveness of in situ preparation for CPBs by using the coating technique.

scholarly journals Modeling and simulation of free radical polymerization of styrene under semibatch reactor conditions

2003 ◽  
Vol 1 (1) ◽  
pp. 69-90 ◽  
Author(s):  
Silvia Curteanu
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Monomer Conversion ◽  
Gel Effect ◽  
Dead End ◽  
Polymer Properties ◽  
Different Temperatures ◽  
Semibatch Reactor ◽  
Kinetic Diagram

AbstractThe first part of this approach is concerned with the elaboration of a radical polymerization model of styrenne, based on a kinetic diagram that includes chemical and thermal initiation, propagation, termination by recombination and chain transfer to the monomer. Furthermore, volume contraction during polymerization is considered, as well as the gel and glass effects. The mathematical formalism that describes the model in terms of moments is explored in detail. The model was then used to predict the changes in monomer conversion and molecular weight after intermediate addition of initiator and monomer. The results of this operation are dependent on the conditions of the reaction mass, quantity, and moment of substance addition. Therefore, the simulations were performed at different times with respect to the gel effect; before, during and after this phenomenon, and also with respect to different temperatures and initiators. Increasing the initiator concentration before the gel effect leads to an earlier appearance of the phenomenon and to a decrease in molecular weight. The ratio $$\bar M_w /\bar M_n $$ reveals a polydispersity index smaller for the intermediate addition of initiator. No significant changes take place during or after the gel effect. If along with the initiator, unreacted monomver (used to dissolve the initiator) enters the reactor, a small dip in conversion is observed. The general conclusion of this paper reveals the intermediate addition of initiator as a method to control polymer properties and to prevent the “dead-end” polymerization of styrene.

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