The Properties of Weak Solutions of N-Vinylpyrrolidone and Methyl Methacrylate Copolymers in Dimethylformamide

2017 ◽  
Vol 44 (12) ◽  
pp. 23-28
Author(s):  
O.I. Nikolaeva ◽  
T.S. Usacheva ◽  
T.A. Ageeva ◽  
O.I. Koifman
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Intrinsic Viscosity ◽  
Weak Solutions ◽  
Mean Square ◽  
Influence Of Temperature ◽  
Methacrylate Copolymers ◽  
Huggins Constant ◽  
The Mean ◽  
Mean Square Distance

The rheology of solutions of N-vinylpyrrolidone and methyl methacrylate copolymers in dimethylformamide in the temperature range 20–35°C was studied. The influence of temperature and of the molecular weight and composition of the copolymers on their interaction with the solvent was shown, expressed quantitatively in terms of intrinsic viscosity, the Huggins constant, and the mean square distance between the ends of the macromolecular chains.

scholarly journals PROPERTIES OF DILUTE SOLUTIONS OF COPOLYMERS OF GLYCIDYLMETHACRYLATE AND METHYLPHEOPHORBIDE «a» IN DIMETHYLFORMAMIDE

2019 ◽  
Vol 62 (7) ◽  
pp. 58-64
Author(s):  
Olga I. Nikolaeva ◽  
Tamara S. Usacheva ◽  
Tatiana A. Ageeva ◽  
Oscar I. Koifman
Keyword(s):  
Molecular Weight ◽  
Chemical Interaction ◽  
Solution Temperature ◽  
Molecular Characteristics ◽  
Mean Square ◽  
Dilute Solutions ◽  
Huggins Constant ◽  
The Mean ◽  
Increasing Temperature ◽  
Mean Square Distance

The study of the rheological properties of polymers, and also the establishment of quantitative dependencies, along with the problem of the relationship of molecular characteristics with the synthesis conditions, is an important scientific and practical task. The solution of this problem gives to predict the behavior of polymers, to develop and find the optimal modes and parameters of obtaining materials with predetermined properties. For a research of chemical interaction between macromolecules in solutions, the dilute solutions rheology of copolymers of glycidylmethacrylate and methylphaeophorbide “a” in dimethylformamide was studied. The study of dilute solutions of the corresponding copolymers was carried out by viscometric method in the temperature range of 20-35 ºC. Copolymers of glycidylmethacrylate and methylphaeophorbide “a” of different composition were obtained by radical copolymerization in solution. The synthesized copolymers are characterized by molecular-weight characteristics determined by gel-permeation chromatography. It is established that the solutions of the copolymers correspond to the systems with the lower critical temperature of dissolution. The belonging of the studied solutions to the systems with the lower critical dissolution temperature is confirmed by the dependence of the Huggins constant on the temperature. From the obtained results it follows that the ball of the macromolecule shrinks with increasing temperature. The influence of solution temperature, molecular weight and composition of copolymers on their interaction with the solvent, expressed quantitatively through the parameters of the characteristic viscosity, the Huggins constant, the mean-square distance between the ends of macromolecular chains, is shown. The mean-square distance between the ends of the chains of polymer in the solution was estimated by the equation of Flory-Fox. It is shown that for the studied copolymers the specific index decreases with increasing temperature. It was determined that the introduction of the porphyrin fragment into the structure of the polymer macromolecule retains the character of the interaction of the macromolecular tangle with the solvent.

Effect on Polymer Chain Structure Caused by the Molar Fraction of 4-Hydroxybutyrate in Poly(3-hydroxybutyrate- co -4-hydroxybutyrate)

2012 ◽  
Vol 602-604 ◽  
pp. 776-780
Author(s):  
Zhi Qiang Li ◽  
Mei Li ◽  
Wei Jia Fan
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Polymer Chain ◽  
Molar Fraction ◽  
Chain Structure ◽  
The Other ◽  
Mean Square ◽  
Polarizing Microscope ◽  
Other Hand ◽  
The Mean

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)copolymer [P(3HB-co-4HB)] is a kind of biodegradable high molecular polymer produced by bioaccumulation. Because of the good biodegradability and biocompatibility, P(3HB-co-4HB)s have attracted wide attention . At first, the intrinsic viscosity[η] in good solvent of P(3HB-co-4HB) s with varying contents of 4HB was investigated in different temperature. Second, observed the changes of crystallization gathered state caused by the varying contents of 4HB by polarizing microscope. The results show that to the P(3HB-co-4HB)s in same molecular weight, the intrinsic viscosity[η] in good solvent barely changes when the mole fractions of 4HB increase. On the other hand, the mean square end to end distances[0] of macromolecular flexible chains increase with the mole fractions of 4HB. At the same time, the states of aggregation change from spherulites to dendrites. In this investigation, we discuss the reasons of the differences in depth.

Synthesis of Microcrystalline Cellulose Grafting Poly (methyl methacrylate) Copolymers by ATRP in 1-Allyl-3-Methylimidazolium Chloride

2012 ◽  
Vol 621 ◽  
pp. 157-161 ◽  
Author(s):  
Er Jun Tang ◽  
Miao Yuan ◽  
Liang Li ◽  
Feng Bian ◽  
Di Shun Zhao
Keyword(s):  
Molecular Weight ◽  
Ionic Liquid ◽  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
1H Nmr ◽  
Microcrystalline Cellulose ◽  
Methacrylate Copolymers ◽  
Covalently Bonded ◽  
Ft Ir

The microcrystalline cellulose grafting polymethylmethacrylate (MCC-g-PMMA) copolymer was successfully synthesized by atom transfer radical polymerization (ATRP) using ethanediamine as ligand in Ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). The MCC-g-PMMA was characterized by FT-IR, 1H NMR, SEM and GPC spectroscopies. The results confirmed that the PMMA had been covalently bonded to cellulose backbone. The molecular weight of graft copolymers linearly increased during the polymerization and presented a low polydispersity.

Statistical properties of a polymer chain in the two-parametor approximation

1981 ◽  
Vol 376 (1766) ◽  
pp. 361-375 ◽  
Keyword(s):  
Polymer Chain ◽  
Numerical Data ◽  
Ring Closure ◽  
Radius Of Gyration ◽  
Mean Square ◽  
Virial Series ◽  
The Mean ◽  
Diagrammatic Method ◽  
Mean Square Distance ◽  
Self Avoiding Walks

The diagrammatic method developed in a previous paper is used to derive two terms of the virial expansion for the mean square distance from the origin, the mean square radius of gyration, and the probability of ring closure for a lattice model of a simple polymer chain. It is found that the logarithmic terms in the partition function cancel in the virial series for these universal quantities. The universality hypothesis is tested with the numerical data for self-avoiding walks (s.a.w.) for different lattices. The virial series is combined with the s.a.w. results to provide formulae for the expansion factor as a function of the excluded volume.

The thermal degradation of polyvinyl compounds IV. The thermal degradation of the methyl methacrylate copolymers with glycol dimethacrylate and acrylonitrile

1949 ◽  
Vol 199 (1056) ◽  
pp. 39-55 ◽  
Keyword(s):  
Molecular Weight ◽  
Thermal Degradation ◽  
Methyl Methacrylate ◽  
The Other ◽  
Glycol Dimethacrylate ◽  
Acrylonitrile Copolymer ◽  
Molecular Weights ◽  
Quantitative Calculation ◽  
Methacrylate Copolymers ◽  
Cross Links

The effect upon degradation of cross-links, formed by copolymerizing small amounts of glycol dimethacrylate with the methyl methacrylate, and small amounts of acrylonitrile units in the chains has been investigated. Cross-links make no difference to the degradation characteristics according to rate measurements. Molecular weights could not be measured in this case owing to the insolubility of the polymer. The methyl methacrylate-acrylonitrile copolymer degrades in quite a different way from polymer composed of homogeneous methyl methacrylate chains. In this case the chain ruptures initially at or near the acrylonitrile units, the molecular weight falling very rapidly in the initial stages of the reaction. One side of the break is terminated by an acrylonitrile unit which cannot degrade but the other side may sooner or later degrade to the next acrylonitrile unit along the chain. The induction period observed is probably due to the time taken to build up an appreciable concentration of such degradable ends. A quantitative calculation agrees well with this theory.

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