scholarly journals In-line monitoring of latex-particle size during emulsion polymerizations with a high polymer content of more than 60%

RSC Advances ◽  
2020 ◽  
Vol 10 (44) ◽  
pp. 26528-26534
Author(s):  
Laurence Isabelle Jacob ◽  
Werner Pauer
Keyword(s):  
Particle Size ◽  
Latex Particle ◽  
Density Wave ◽  
Photon Density ◽  
Particle Sizes ◽  
Polymer Content ◽  
High Polymer ◽  
Food Chemistry ◽  
Emulsion Polymerizations

The photon density wave (PDW) spectroscopy is established in the fields of biochemistry and food chemistry as an online analytical method for the determination of mean particle sizes.

Effects of Particle Size and Method of Milling on Determination of Morphine in Papaver somniferum L. Straw

1982 ◽  
Vol 65 (3) ◽  
pp. 651-654
Author(s):  
Beatriz Ferreira Engelke ◽  
Phillip G Vincent
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Reproducibility Of Results ◽  
Ball Mill ◽  
Papaver Somniferum ◽  
Particle Sizes ◽  
Morphine Content

Abstract Different particle sizes of blade- and ball-milled poppy straw were separated and analyzed for morphine by high pressure liquid chromatography. Morphine content varied up to 70% among the different size particles. This may account for discrepancies observed in percentages of morphine found among random aliquots. Homogenizing a carefully quartered sample of blade-milled straw by further pulverization in a percussion ball mill 2 min and taking a quartered aliquot for morphine analysis improved the reproducibility of results.

Particle Size Study of Smectite Clays from the City of Pedra Lavrada-PB

2014 ◽  
Vol 775-776 ◽  
pp. 377-382
Author(s):  
Mirtys Allamana Ferreira Cardoso ◽  
Alexsandra Cristina Chaves ◽  
M.M. Dantas ◽  
Isabelle Albuquerque da Silva ◽  
I.D.S. Pereira ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Drilling Fluids ◽  
Particle Sizes ◽  
Smectite Clays ◽  
Significant Difference ◽  
Water Based ◽  
The City

The state of Paraíba disposes of one of the largest deposits of smectites in the country. However, these smectites present in their composition elevated contents of accessory minerals, especially quartz. For these clays to become viable to determine technological use it is necessary the elimination of part of these minerals. The particle size analysis of a soil consists in the determination of the size of the particles that constitute it and their distribution in certain intervals. This work aims to study smectite clays from the city of Pedra Lavrada-PB, through the particle size analyses, for the use in water based drilling fluids. The determination of particle size was made by sieving and laser granulometer. Apparent and plastic viscosities were measured from the samples. The clays were left at rest before the test for periods of 7 and 28 days, with and without deflocculant. It was verified that there was no significant difference in the particle sizes in relation to the resting time of the samples.

Determination of Particle-Size Distribution in GR-S Latexes

1954 ◽  
Vol 27 (4) ◽  
pp. 1051-1060 ◽  
Author(s):  
Alfred Nisonoff ◽  
W. E. Messer ◽  
L. H. Howland
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Light And Electron Microscopy ◽  
Wide Distribution ◽  
Plant Production ◽  
Particle Sizes ◽  
Laboratory Centrifuge ◽  
Made In

Abstract A method based on Stokes' law, involving the use of an ordinary laboratory centrifuge, is described for the determination of particle size distribution in GR-S latexes. It is shown to be valid by tests for reproducibility and by comparison with the results of light and electron microscopy. In applying the method, several unusually fluid high-solids latexes made in the pilot plant were found to be characterized by a wide distribution of particle sizes. Data on various latexes in plant production are reported.

Determination of Particle Size in Latex

1953 ◽  
Vol 26 (2) ◽  
pp. 481-486 ◽  
Author(s):  
E. G. Cockbain
Keyword(s):  
Particle Size ◽  
Sodium Dodecyl Sulfate ◽  
Natural Rubber ◽  
Sodium Dodecyl ◽  
Average Particle ◽  
Particle Sizes ◽  
Sulfate Concentration ◽  
Titration Method ◽  
Dodecyl Sulfate

Abstract The soap titration method of determining average particle sizes in synthetic latexes has been modified so as to make it applicable to natural rubber latexes. The method consists essentially in determining the distribution of an added detergent (sodium dodecyl sulfate) between the rubber and aqueous phases at a pH of approximately 6.0, the total dodecyl sulfate concentration being just sufficient for the formation of micelles in the aqueous phase. The average particle sizes of nine ammoniated latexes have been measured, including centrifuged and electrodecanted concentrates, two clonal field latexes and a sample of latex skim.

Determination of Latex Particle Size Distributions by Fractional Creaming with Sodium Alginate

1961 ◽  
Vol 34 (2) ◽  
pp. 433-445 ◽  
Author(s):  
E. Schmidt ◽  
P. H. Biddison
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Sodium Alginate ◽  
Mass Distribution ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Size Distributions ◽  
Particle Size Distributions

Abstract Knowledge of mass distribution of particle sizes in latex is very important to the latex technologist. Therefore, it is desirable to have available a simple method for the determination of mass distribution of particle sizes. This paper presents a method, based on fractional creaming of latex with sodium alginate, which can be used in any laboratory without special equipment. The method is particularly advantageous for analyzing latexes of very wide particle size distributions. When analyzed with an electron microscope, these latexes require counting a very large number of particles. McGavack found that partial creaming of normal hevea latex with ammonium alginate gives concentrates of larger average particle size than the original latex. He found that the average particle size in the cream approaches that of the original latex as the amount of creaming agent is increased. In a previous paper from this laboratory, Schmidt and Kelsey demonstrated that the phenomenon of fractionation according to particle size with increasing amounts of creaming agent is applicable in a wide variety of anionic latex systems and in colloidal silica. Their results indicated also the existence of a quantitative relationship, independent of the nature of the dispersed particles, between the concentration of creaming agent and size of creamed particles. Maron confirmed fractionation with respect to particle size as a consequence of partial creaming with alginate. He showed that the mass average particle sizes of fractions, determined optically, cumulate to that of the original latex. Although the previous paper by Schmidt and Kelsey implied the basic concept of a method of determining particle size distribution by fractional creaming, it was not exploited at that time. In order to adapt the fractional creaming phenomenon to a quantitative method for particle size determination, we required a more precise knowledge of the relation between creaming agent concentration and size of particles creamed. It was proposed to establish this relationship with the aid of the electron microscope. Various factors influencing the creaming of latex, such as polymer concentration, electrolyte, soap content, and variability of the creaming agent, had to be considered in standardizing the creaming procedure.

The relative resistance to escape of leaf and stem particles from the rumen of cattle and sheep

1985 ◽  
Vol 105 (1) ◽  
pp. 9-14 ◽  
Author(s):  
D. P. Poppi ◽  
R. E. Hendricksen ◽  
D. J. Minson
Keyword(s):  
Particle Size ◽  
Animal Species ◽  
Particle Sizes ◽  
Small Particles ◽  
Relative Resistance ◽  
Stages Of Growth ◽  
Two Stages ◽  
Wet Sieving ◽  
Cattle And Sheep

SUMMARYIn a study of the effect of animal species on the threshold particle size leaving the rumen, two grasses cut at two stages of growth and one mature legume were separated into leaf and stem fractions and fed to cattle and sheep. Samples of rumen digesta and faeces were used to determine the validity of using a 1·18 mm porosity screen to separate the rumen particles into large and small pools when studying escape of particles from the rumen. Samples of rumen digesta and faeces were collected for the determination of particle size by wet sieving and the calculation of resistance of particles to passage from the rumen relative to small particles retained on a 0·15 mm sieve.Particles < 1·18 mm but > 0·5 mm had a mean relative resistance to passage of 2·0 and 2·6 for cattle and sheep respectively, compared with resistance values of between 10·9 and 31·2 for particles between 1·18 and 2·36 mm. It is suggested that there is no justification for using different threshold particle sizes for sheep and cattle and that a 1·18 mm sieve may be used to divide the rumen contents of both cattle and sheep into two pools of particles with high and low relative resistance to passage from the rumen.

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