The Effects of Initiating Systems on CPAM Relative Molecular Weight and Strength Properties of Paperboard

2013 ◽  
Vol 821-822 ◽  
pp. 945-948
Author(s):  
Hui Rong Yang ◽  
Chuan Shan Zhao ◽  
Xue Zhang ◽  
Wen Jia Han
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Strength Properties ◽  
Polymerization Temperature ◽  
Initiator Concentration ◽  
Redox Systems ◽  
Aqueous Polymerization ◽  
Relative Molecular Weight

initiator is one of the most important conditions of synthesizing efficient strength agent CPAM. To begin with initiating mechanism, three redox systems of acrylamide aqueous polymerization (NH4)2S2O8/ Na2SO3, K2S2O8/NaHSO3and K2S2O8/Na2S2O4have been studied. The effects of different kinds of initiator, initiator concentration, and monomer concentration as well as polymerization temperature on relative molecular weight and strength effects of CPAM have been investigated. K2S2O8/Na2SO3is the most useful system in synthesizing efficient strength agents.

Polymerization of n-butyl methylacrylate using bis(β- ketoamino)nickel(II)/MAO catalytic systems

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaohui He ◽  
Yiwang Chen ◽  
Yongming Liu ◽  
Muqing Chen ◽  
Shuxian Yu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Temperature ◽  
Moderate Activity ◽  
Polymerization Time ◽  
Catalytic Systems ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Broad Molecular Weight Distribution ◽  
C Nmr

AbstractThe polymerizations of n-butyl methylacrylate (nBMA) were carried out using bis(β-ketoamino)nickel(II) complexes (Ni[CH3C(O)CHC(NR)CH3]2: R = phenyl, 1; R = naphthyl, 2) in combination with methylaluminoxane (MAO) in toluene. The effect of parameters such as polymerization temperature, Al/Ni molar ratios, polymerization time, and monomer concentration, on catalytic polymerization activity and polymer molecular weights, were examined in detail. Both of the nickel(II) catalytic systems exhibited moderate activity, and produced P(nBMA) with high molecular weight and relatively broad molecular weight distribution (Mw/Mn=2.0~3.0. The obtained polymer has been characterized by means of FTIR, 1H NMR, 13C NMR, DSC, and WAXD technique and was confirmed to be syndio-rich stereospecific P(nBMA).

scholarly journals A Complexed Initiating System AlCl3·Phenetole/TiCl4·H2O with Dominant Synergistic Effect for Efficient Synthesis of High Molecular Weight Polyisobutylene

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2121
Author(s):  
Yulong Jin ◽  
Liang Chen ◽  
Xing Guo ◽  
Linfeng Xu ◽  
Zhihua Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Synergistic Effect ◽  
High Molecular Weight ◽  
Monomer Concentration ◽  
Catalyst System ◽  
Polymerization Temperature ◽  
Simple Preparation ◽  
Order Of Magnitude ◽  
Unique Approach ◽  
High Molecular Weight Polyisobutylene

A complexed initiating system AlCl3·phenetole/TiCl4·H2O was prepared by simply compounding AlCl3/phenetole and TiCl4/H2O and used for cationic polymerization of isobutylene. It was found AlCl3·phenetole/TiCl4·H2O exhibited activities 1.2–3 times higher than those of AlCl3/phenetole, and more than an order of magnitude higher than those of TiCl4/H2O, which indicated a notable synergistic effect produced in the complexed system. In addition, due to the higher activity of AlCl3·phenetole/TiCl4·H2O, lower coinitiator concentration and polymerization temperature, as well as higher monomer concentration were more favored for this complexed initiating system to produce polyisobutylene (PIB) with reasonable molecular weight (Mw) and molecular weight distribution (MWD). Furthermore, high molecular weight polyisobutylene (HPIB) with Mw = 1–3 × 105 g·mol−1 could be successfully produced by the complexed catalyst system at Tp = −60 to −40 °C. As a whole, the high activity as well as the simple preparation procedures of the complexed initiating system offer us a unique approach for the production of HPIB with improved efficiency.

scholarly journals Oxidative polymerization of acrylamide in the presence of thioglycolic acid

2005 ◽  
Vol 3 (4) ◽  
pp. 705-720 ◽  
Author(s):  
Cemal Özeroğlu ◽  
Sacide Erdoğan
Keyword(s):  
Molecular Weight ◽  
Thioglycolic Acid ◽  
Graphite Furnace ◽  
Oxidative Polymerization ◽  
Monomer Concentration ◽  
Water Soluble ◽  
Polymerization Reaction ◽  
Molar Ratio ◽  
Polymerization Time ◽  
Redox Systems

AbstractChemical polymerization of acrylamide at room temperature was examined by using thioglycolic acid-cerium (IV) sulfate and thioglycolic acid-KMnO4 redox systems in acid aqueous medium. Water soluble polyacrylamides containing thioglycolic acid end groups were synthesized. The effects of the molar ratio of acrylamide to Ce(IV) nAAm/nCe(IV), the polymerization time, the temperature, the monomer concentration, the molar ratio of cerium (IV) sulfate to thioglycolic acid and the concentration of sulfuric acid on the yield and molecular weight of polymer were investigated. Lower molar ratios of acrylamide/Ce(IV) at constant monomer concentration resulted in an increase in the yield but a decrease in molecular weight of polymer. The increase of reaction temperature from 20 to 70°C resulted in a decrease in the yield but generally resulted in a constant value for the molecular weight of polymer. With increasing polymerization time, the yield and molecular weight of polymer did not change substantially. Ce(IV) and Mn(VII) ions are reduced to Ce(III) and Mn(II) ions respectively in the polymerization reaction. The existence of Ce(III) ion bound to polymer was investigated by UV-visible spectrophotometry and fluoresce measurements. The amount of Mn(II) incorporated into the polymer was determined using graphite furnace atomic absorption spectrometry. The mechanism of this phenomenon is discussed.

Synthesis of Ultra-High Molecular Weight Polyacrylonitrile (UHMWPAN) by Aqueous Suspension Polymerization

2015 ◽  
Vol 1120-1121 ◽  
pp. 615-619
Author(s):  
Hui Yu Jiang ◽  
Mei Hua Zhou ◽  
Ding Pan
Keyword(s):  
Molecular Weight ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Average Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Process ◽  
Polymerization Temperature ◽  
Different Temperatures ◽  
Total Monomer Concentration ◽  
Ultra High Molecular Weight

Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).

scholarly journals Synthesis and kinetic studies of TiO2/polystyrene composite particles by emulsion polymerization

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhang Jianmin ◽  
Peng Zheng ◽  
Sun Xiuguo ◽  
Wang Caihui ◽  
Gao Jungang
Keyword(s):  
Emulsion Polymerization ◽  
Sodium Dodecyl ◽  
Monomer Concentration ◽  
Kinetic Studies ◽  
Composite Particles ◽  
Polymerization Temperature ◽  
Initiator Concentration ◽  
Potassium Persulphate ◽  
Initial Monomer ◽  
Emulsifier Concentration

AbstractIn the presence of titanium dioxide (TiO2) nanoparticles, emulsion polymerization of styrene with sodium dodecyl sulphate (SDS) as an emulsifier and potassium persulphate as an initiator was investigated in detail. It was shown that SDS concentration influences the morphology of the composite particles in higher degree. Moreover, the effects of operating variables such as emulsifier concentrations, initiator concentration, monomer concentration, and polymerization temperature on the kinetic features were also examined. The kinetic data showed that at conditions studied, the rate of polymerization over interval II was proportional to the 0.68 power of the initial emulsifier concentration, to the 2.2 power of the initial initiator concentration and to the 1.6 power of the initial monomer‟s concentration. The initiator concentration has a dominant effect on the rate of the polymerization. The appropriate conditions for polymerization were obtained when emulsifier concentration of 6.5×10-3 mol·L-1, initiator concentration of 4.4×10-3 mol·L-1, the polymerization temperature of 75 °C and the initial monomer‟s concentration of 0.288 mol·L-1 were used. The polymerization rate obtained is more favorable than that of the conventional emulsion approach. The experimental results can be reasonably ascribed to the nucleation mechanism of “TiO2/SDS” micelles in the emulsion polymerization of styrene.

Effects of Polymerization Parameters on Aqueous Deposited Copolymerization of Acrylonitrile and Itaconic Acid

2013 ◽  
Vol 774-776 ◽  
pp. 508-511
Author(s):  
Ya Qi Zhao ◽  
Qiao Feng ◽  
Ling Zhi Du
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Itaconic Acid ◽  
Temperature Region ◽  
Monomer Concentration ◽  
Initiator Concentration ◽  
Molecular Weights ◽  
Total Monomer Concentration

Pure powdery high molecular weight polyacrylonitrile (HMW-PAN) copolymers were firstly synthesized by aqueous deposited polymerization (ADP) technique employing 2,2'-Azobis (isobutyramidine) dihydrochloride (AIBA) as initiator and itaconic acid (IA) as comonomer. Various PAN polymers were obtained through changing different polymerization parameters. It is indicated that with the increase of total monomer concentration, initiator concentration, reaction temperature and reaction time, polymerization conversions of PAN copolymers all increased. While the molecular weights become greater with the increase of total monomer concentration. With the increase of initiator concentration and reaction temperature (under higher reaction temperature region), the molecular weights decreased. However, the molecular weights only had very little decrease at the end of long extension of reaction time.

Breaking Down the Supramolecular Ensemble: Single-Molecule Studies of the Concentration Dependence of Main-Chain Supramolecular Polymer Molecular Weight Distributions on Surfaces

2010 ◽  
Vol 63 (4) ◽  
pp. 624
Author(s):  
Michael J. Serpe ◽  
Jason R. Whitehead ◽  
Stephen L. Craig
Keyword(s):  
Molecular Weight ◽  
Single Molecule ◽  
Monomer Concentration ◽  
Supramolecular Polymer ◽  
Force Microscopy ◽  
Molecular Weight Distributions ◽  
Atomic Force ◽  
Multi Stage ◽  
Single Molecule Studies ◽  
Supramolecular Ensemble

Single molecule atomic force microscopy (AFM) studies of oligonucleotide-based supramolecular polymers on surfaces are used to examine the molecular weight distribution of the polymers formed between a functionalized surface and an AFM tip as a function of monomer concentration. For the concentrations examined here, excellent agreement with a multi-stage open association model of polymerization is obtained, without the need to invoke additional contributions from secondary steric interactions at the surface.

Environmentally Benign Adhesive Synthesized by Dispersion Copolymerization of Styrene and Butyl Acrylate

2006 ◽  
Vol 11-12 ◽  
pp. 757-760
Author(s):  
Jun Ying Zhang ◽  
Peng Dou
Keyword(s):  
Molecular Weight ◽  
Butyl Acrylate ◽  
Monomer Concentration ◽  
Environmentally Benign ◽  
Functional Monomer ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Stabilizer Concentration ◽  
Ethanol Medium ◽  
Weight Distributions

Environmentally benign adhesive was synthesized by dispersion copolymerization of styrene(St) and butyl acrylate (BA) in an ethanol medium with benzoyl peroxide (BPO) as the initiator and poly(vinylpyrrolidone) as the stabilizer in the presence of acrylic acid(AA) as the functional monomer. The effect of the concentration of stabilizer, initiator and functional monomer on the conversions, molecular weights and molecular weight distributions was investigated. The results show that the conversions almost keep invariable with the increasing of stabilizer concentration, but the molecular weights increase and molecular weight distributions decrease. Conversions increase with the increasing of initiator concentration, but the molecular weights and molecular weight distributions decrease. However with the increasing of functional monomer concentration, conversions and molecular weight distributions increase but the molecular weights decrease.

Study on the Preparation and Characterization of Carboxyl Terminated Poly(L-Lactic Acid) (PLLA) Prepolymers

2017 ◽  
Vol 872 ◽  
pp. 165-170
Author(s):  
Shi Chao Lu ◽  
Yang Chuan Ke ◽  
Qian Zhou ◽  
Zhao Rui Meng ◽  
Guo Liang Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Average Molecular Weight ◽  
Polymerization Temperature ◽  
Capping Agent ◽  
Molar Amount ◽  
Optimum Reaction ◽  
Catalyst Content ◽  
End Capping

The carboxyl terminated poly (L-lactic acid) (PLLA) prepolymers were prepared via polycondensation of L-lactic acid and 1,6-adipic acid (end capping agent) under the catalyst of stannous octoate. The effects of synthetic condition, such as reaction temperature, amount of catalyst, content of the end capping agent, etc, on the molecular weight of PLLA were discussed. Fourier transform infrared and 1H nuclear magnetic resonance were used to characterize the PLLA prepolymers. The results indicated that the polycondensation was performed under an optimum reaction condition as following: the amount of the catalyst was 500 ppm based on the mass of lactic acid, the amount of the end capping agent was 1% (the molar amount of the lactic acid), and the polymerization temperature was 170 °C. The viscosity-average molecular weight of the product reached 2.826×104 at this polymerization temperature and the yield was 73.34%.

ATRP Synthesis and Characterization of μ,αω-allyl-terminated Macromonomers as Precursors for End-linked Gels and Hydrogels

2003 ◽  
Vol 774 ◽  
Author(s):  
Lucy Vojtova ◽  
Nicholas J. Turro ◽  
Jeffrey T. Koberstein
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Monomer Conversion ◽  
Catalyst System ◽  
Linear Increase ◽  
Butyl Methacrylate ◽  
First Order Kinetics ◽  
Significant Difference ◽  
Ft Ir

AbstractSynthesis of α,ω-allyl-terminated telechelic macromonomers based on poly(tert-butyl methacrylate) (poly(t-BMA)) and poly(methacrylic acid) (poly(MAA)) was studied with the aim of preparing end-linked gels and hydrogels. Low molecular weight α-allyl-terminated poly(t-BMA) macromonomers with narrow polydispersities (Mw/Mn = 1.16) were synthesized via controlled atom transfer radical polymerization (ATRP) using a Cu(I)Br/N,N,N',N',N',N'-hexamethyltriethylenetetraamine catalyst system in conjunction with an allyl-2-bromoisobutyrate as the functional initiator. The polymerizations exhibited a linear increase of molecular weight in direct proportion to the monomer conversion and first-order kinetics with respect to monomer concentration. No significant difference was found between using polar or non-polar solvents (tetrahydrofuran or benzene, respectively). Optimization of reaction conditions to obtain the highest degree of active terminal bromine is discussed. Quenching the ATRP reaction with allyltributyltin yielded α,ω-allyl-terminated poly(t-BMA) macromonomers by replacing the terminal bromine with ω-allyl functional group. Poly(MAA) macromonomers were prepared by deprotection of the tert-butyl group from α,ω-allyl-terminated poly(t-BMA) macromonomers using concentrated trifluoroacetic acid at room temperature. Successful synthetic steps were confirmed by 1H NMR, FT-IR and MALDI-TOF MS analyses. The α,ω-allyl-terminated macromonomers were proven to be candidates for further polymerization by forming end-linked, non-soluble gels.

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