Investigation of the conditions of negative thixotropy of poly(methyl methacrylate) solutions in low-viscosity solvents. I. Influence of polymer concentration, temperature and thermodynamic quality of solvent

1971 ◽  
Vol 36 (5) ◽  
pp. 2042-2048 ◽  
Author(s):  
O. Quadrat
Keyword(s):  
Methyl Methacrylate ◽  
Polymer Concentration ◽  
Poly Methyl Methacrylate ◽  
Low Viscosity ◽  
Negative Thixotropy ◽  
Thermodynamic Quality

Preparation and Characterization of Poly(Methyl Methacrylate) (PMMA) Fibers by Electrospinning

2019 ◽  
Vol 811 ◽  
pp. 163-169 ◽  
Author(s):  
Ervin Tri Suryandari ◽  
Muhammad Ali Zulfikar ◽  
Rino R. Mukti ◽  
Muhamad Nasir
Keyword(s):  
Methyl Methacrylate ◽  
Flow Rate ◽  
Supply Voltage ◽  
High Surface ◽  
Polymer Concentration ◽  
Diameter Distribution ◽  
Solution Flow Rate ◽  
Simple Method ◽  
Poly Methyl Methacrylate ◽  
Small Pore

Fibers are materials with advantageous properties such as lightweight material properties, has small pore size, and has high surface area, porosity,and permeability. An easy and simple method to prepare fibers is electrospinning. Using this method poly(methyl methacrylate) (PMMA) fibers were prepared. Several parameters include polymer concentration, solution flow rate, the distance of the nozzle tip to the collector, and the applied voltage were investigated to control the morphology, structure, and diameter of PMMA fibers. The Optimal electrospinning conditions for PMMA fibers production were a PMMA concentration is 8% (w/v), a power supply voltage is 20 kV, a distance of the tip of the nozzle to the ground collector is 15 cm, and a flow rate is 0.004 mL/min. The diameter distribution and morphology of the fibers were determined and characterized by Optical Microscopy and Scanning Electron Microscope (SEM), which showed that the produced fiber had an average diameter of 1.4925 µm, the contact angle of fiber PMMA is 125.307o and the spreading time of fibers PMMA is about 360 minutes

Solubility and Thermoresponsiveness of PMMA in Alcohol-Water Solvent Mixtures

2010 ◽  
Vol 63 (8) ◽  
pp. 1173 ◽  
Author(s):  
Richard Hoogenboom ◽  
C. Remzi Becer ◽  
Carlos Guerrero-Sanchez ◽  
Stephanie Hoeppener ◽  
Ulrich S. Schubert
Keyword(s):  
Methyl Methacrylate ◽  
Pure Water ◽  
Polymer Concentration ◽  
Polymer Processing ◽  
Solution Temperature ◽  
Solvent Mixtures ◽  
Poly Methyl Methacrylate ◽  
Water Solvent ◽  
Alcohol Water ◽  
Hysteresis Behaviour

To reduce the environmental burden of polymer processing, the use of non-toxic solvents is desirable. In this regard, the improved solubility of poly(methyl methacrylate) (PMMA) in ethanol/water solvent mixtures is very appealing. In this contribution, detailed investigations on the solubility of PMMA in alcohol/water solvent mixtures are reported based on turbidimetry measurements. PMMA revealed upper critical solution temperature transitions in pure ethanol and ethanol/water mixtures. However, around 80 wt-% ethanol content a solubility maximum was observed for PMMA as indicated by a decrease in the transition temperature. Moreover, the transition temperatures increased with increasing PMMA molar mass as well as increasing polymer concentration. Careful analysis of both heating and cooling turbidity curves revealed a peculiar hysteresis behaviour with a higher precipitation temperature compared with dissolution with less than 60 wt-% or more than 90 wt-% ethanol in water and a reverse hysteresis behaviour at intermediate ethanol fractions. Finally, the transfer of poly(styrene)-block-poly(methyl methacrylate) block copolymer micelles from the optimal solvent, i.e. aqueous 80 wt-% ethanol, to almost pure water and ethanol is demonstrated.

scholarly journals Self-Assembly of Molecular Brushes with Polyimide Backbone and Amphiphilic Block Copolymer Side Chains in Selective Solvents

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2922
Author(s):  
Maria Simonova ◽  
Ivan Ivanov ◽  
Tamara Meleshko ◽  
Alexey Kopyshev ◽  
Svetlana Santer ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Methyl Methacrylate ◽  
Self Assembly ◽  
Amphiphilic Block Copolymer ◽  
Side Chains ◽  
Poly Methyl Methacrylate ◽  
Molecular Brushes ◽  
Selective Solvents ◽  
Significant Difference ◽  
Thermodynamic Quality

Three-component molecular brushes with a polyimide backbone and amphiphilic block copolymer side chains with different contents of the “inner” hydrophilic (poly(methacrylic acid)) and “outer” hydrophobic (poly(methyl methacrylate)) blocks were synthesized and characterized by molecular hydrodynamics and optics methods in solutions of chloroform, dimethylformamide, tetrahydrofuran and ethanol. The peculiarity of the studied polymers is the amphiphilic structure of the grafted chains. The molar masses of the molecular brushes were determined by static and dynamic light scattering in chloroform in which polymers form molecularly disperse solutions. Spontaneous self-assembly of macromolecules was detected in dimethylformamide, tetrahydrofuran and ethanol. The aggregates size depended on the thermodynamic quality of the solvent as well as on the macromolecular architectural parameters. In dimethylformamide and tetrahydrofuran, the distribution of hydrodynamic radii of aggregates was bimodal, while in ethanol, it was unimodal. Moreover, in ethanol, an increase in the poly(methyl methacrylate) content caused a decrease in the hydrodynamic radius of aggregates. A significant difference in the nature of the blocks included in the brushes determines the selectivity of the used solvents, since their thermodynamic quality with respect to the blocks is different. The macromolecules of the studied graft copolymers tend to self-organization in selective solvents with formation of a core–shell structure with an insoluble solvophobic core surrounded by the solvophilic shell of side chains.

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