Solution-SBR Powders

1976 ◽  
Vol 49 (1) ◽  
pp. 126-139
Author(s):  
D. N. Schulz ◽  
L. E. Calihan ◽  
D. P. Tate
Keyword(s):  
Powder Particle Size ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Bound Rubber ◽  
Powder Blends ◽  
Powder Particles ◽  
Filler Dispersion ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Powdered Rubber

Abstract This paper describes the advantageous cross-fertilization of solution-masterbatch technology and powdered-rubber processing. A nonlatex method has been developed for the preparation of free-flowing solution-SBR powders. The factors affecting powder particle size and morphology have been identified. Optimization of the preparative variables has resulted in dry-blendable solution-SBR powders. As a consequence of a low shear history, the solution-SBR powder blends show distinctive rubber-filler, rheological, and physical properties. For example, unvulcanized solution-SBR powder compounds evince higher molecular weights and lower bound-rubber contents than conventional mixes. Yet, the microscopic filler dispersion of these two types of compounds appears similar. Uncured solution-SBR powder blends also exhibit stiffer rheological behavior than conventional mixes. Furthermore, this stiffness tends to persist in the vuleanizates derived from these powdered compounds. Vulcanizate excellence depends primarily upon fineness of the powder particles and absence of free filler. Conditions have been found which permit the direct ribbon extrusion of tire tread, without prior compacting or milling. Conventional single-screw ribbon- tread extruders are sufficient to produce treads of high quality.

Investigation on Feedstock Preparation for Micro-Cemented Carbide Injection Molding

2018 ◽  
Vol 18 (2) ◽  
pp. 96-102
Author(s):  
Abdolali Fayyaz ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong
Keyword(s):  
Flow Behavior ◽  
Flow Characteristics ◽  
High Viscosity ◽  
Cemented Carbide ◽  
Solid Loading ◽  
Powder Particle Size ◽  
Powder Particles ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Feedstock Preparation

Abstract This research was focused on mixing of submicron cemented carbide (WC-Co-VC) powder and binder. WC-Co-VC powder particle size and morphology were analyzed by laser diffraction and field emission scanning electron microscopy. The WC-Co-VC powder was kneaded with a paraffin wax based binder system. Based on critical solid loading, the feedstock with different solid loadings between 49 to 51 vol.% was prepared. Finally, the flow behavior of different feedstocks was investigated. Morphology of powder revealed that the particles of powder are slightly agglomerated and irregular in shape. The result of mixing indicted that the torque value increases as the solid loading increase from 49 vol.% to 51 vol.%. The feedstock exhibited homogeneity and the powder particles are homogenously coated with binder. The feedstock with solid loading of 51 vol.% is sensitive to temperature and showed high viscosity values. The feedstock with solid loadings of 49 and 50 vol.% had good compatibility and flow characteristics.

Morphology of as-precipitated and dried powders in the PLZT system

1986 ◽  
Vol 44 ◽  
pp. 838-839
Author(s):  
R. W. Schwartz ◽  
D. A. Payne
Keyword(s):  
Freeze Drying ◽  
Ammonium Hydroxide ◽  
Ph Control ◽  
Continuous Reactor ◽  
Powder Particle Size ◽  
Oxide Ceramic ◽  
Chemical Preparation ◽  
Electro Optic ◽  
Particle Size And Morphology ◽  
Size And Morphology

High quality ceramic products, such as transparent electro-optic materials, require better control of chemical composition, powder particle size and morphology, than is offered by conventional mixed-oxide ceramic processing methods. Chemical preparation procedures can be used to prepare powders with the required characteristics of controlled size and morphology.Precipitated hydroxides in the PLZT system (lead lanthanum zirconium titanate) were prepared in a constant volume continuous reactor, following a procedure suggested by Murata, which uses nitrate and chloride precursors, and ammonium hydroxide for pH control. After washing with deionized water, the powders were dried by either spray-drying or freeze-drying in liquid nitrogen.

ULTRAFINE PRIMARY SILICON PARTICLES IN PHOSPHORUS-MODIFIED HYPEREUTECTIC AL-SI ALLOY POWDERS PRODUCED BY SAMD METHOD

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3304-3310 ◽  
Author(s):  
P. DELSHAD-KHATIBI ◽  
F. AKHLAGHI
Keyword(s):  
Primary Silicon ◽  
Powder Particle Size ◽  
Primary Si ◽  
Solid Media ◽  
Aluminum Droplets ◽  
Rotating Impeller ◽  
Powder Particles ◽  
Size And Morphology ◽  
Phosphorus Modification ◽  
Average Size

In the present study, alloy powder batches of Al-20Si (wt. %) were generated by SAMD technique using NaCl as the solid media. The method consists of introducing and mixing a specified amount of NaCl particles (mean diameter 254 μm) in aluminum melt at the temperature of 710°C. Melt disintegration occurs in 5 min by kinetic energy transfer from a rotating impeller (1400 rpm) to the metal via the solid atomizing medium ( NaCl particles). The resulting mixture of aluminum droplets and NaCl particles are subsequently quenched in water to dissolve NaCl and solidify Al droplets to produce powder particles. In order to investigate the effect of phosphorus modification on the size and morphology of the primary Si particles, the SAMD technique was also performed to produce Al-20Si -0.015P powder particles. The resultant powders were screened through 6 different sized sieves ranging from 38 to 500 μm and different powder fractions were cold mounted, polished and studied by optical microscopy. It was concluded that for both un-modified and modified alloys, there was a decrease in the size of primary Si particles corresponding to a decrease in the powder particle size. However, the same sized phosphorus modified powders exhibited considerably finer primary Si particles in which the average size of these ultrafine Si particles was about 1.1 μm for the smallest sieved particles.

Honokiol-Based Nanomedicine Decorated with Ethylene Glycols Derivatives Promotes Antitumor Efficacy

2021 ◽  
Vol 17 (8) ◽  
pp. 1564-1573
Author(s):  
Zhengqi Dong ◽  
Hanhong Qiu ◽  
Meihua Han ◽  
Rui Wang ◽  
Yifei Guo ◽  
...  
Keyword(s):  
Particle Size ◽  
Antitumor Activity ◽  
Ethylene Glycol ◽  
Particle Diameter ◽  
Weight Ratio ◽  
Antitumor Efficacy ◽  
Factors Affecting ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Ethylene Glycol Derivatives

Honokiol-loaded nanoparticles (HK-loaded NPs) exhibit potential antitumor activity; however, the factors affecting their antitumor efficacy are still unclear and need to be explored. This research was aimed to systematically estimate the influence of feed weight ratio (FWR) and nanocarrier structure on antitumor activity. Accordingly, three types of ethylene glycol derivatives, including linear poly(ethylene glycol) with molar mass of 2000 (PEG45), first and second generation oligo(ethylene glycol) dendrons (G1 and G2) were used as nanocarriers, and a series of HK-loaded NPs with different FWR were prepared successfully using the evaporation-ultrasonication method. These NPs showed similar stability but demonstrated differences with respect to particle size, morphology, cumulative profile, and antitumor efficacy. The influence of the FWR was studied using G1 dendrons as nanocarriers; the results indicated that the particle size and morphology of G1 NPs were significantly affected, and G1 NPs (8/1), with the FWR of 8/1 for HK versus G1 dendron, exhibited the highest antitumor activity among all G1 NPs. Furthermore, the influence of nanocarrier structure was investigated at the FWR of 4/1; the findings revealed reduction in the particle diameter from 280 nm to 109 nm and change in morphology from sphere to flower-like structure with an increase in the branch degree from linear to dendron. Moreover, G2 NPs (4/1), with the FWR of 4/1 for HK versus G2 dendron, carrying the highest branch degree exhibited the greatest antitumor efficacy among all. These results are suggestive of influence of particle size and morphology on antitumor efficacy of HK-loaded NPs. Conclusively, this study demonstrated nanocarrier structure and the FWR significantly affect the antitumor efficacy of NPs, which should be optimized for designing nanoscale delivery systems.

Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Hollow Spheres ◽  
Ordered Mesoporous Silica ◽  
Direct Manipulation ◽  
Flow Synthesis ◽  
Precise Control ◽  
Ordered Mesoporous ◽  
Particle Size And Morphology ◽  
Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

scholarly journals Comparison of the sensitivity of Western blotting between PVDF and NC membranes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Polyvinylidene Fluoride ◽  
Staining Intensity ◽  
Detection Sensitivity ◽  
Key Factors ◽  
Post Translational Modifications ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Direct Blue ◽  
The Relationship

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

Sorption of GR-S Type of Polymer on Carbon Black. III. Sorption by Commercial Blacks

1953 ◽  
Vol 26 (1) ◽  
pp. 102-114 ◽  
Author(s):  
I. M. Kolthoff ◽  
R. G. Gutmacher
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Molecular Weights ◽  
Bound Rubber ◽  
Flow Through ◽  
Peculiar Behavior

Abstract The sorption capacities toward GR-S five commercial carbon blacks are in decreasing order: Spheron-6, Vulcan-1, Philblack-0, Sterling-105, Philblack-A. Apparently, the sorption is not related to surface area. The sorption on Vulcan-1 of GR-S from its solutions in seven different solvents or mixtures of solvents increases with decreasing solvent power for the rubber. The sorption curves of two “cold rubbers,” polymerized at −10 and +5° respectively, showed little difference from that of 50° GR-S. Previous heating of carbon black in nitrogen at 500 or 1100° increased the sorption by about 20 per cent over unheated carbon. Air-heating of carbon black at 425° did not cause a difference in the sorption from benzene solution, but produced an increase in the sorption of rubber from n-heptane solution. In the range 75% butadiene-25% styrene to 5% butadiene-95% styrene, there is practically no effect of the degree of unsaturation on the sorption. Polystyrene of high intrinsic viscosity exhibits a peculiar behavior with furnace blacks. Vulcan-1 sorbed microgel as well as the sol fraction from n-heptane solutions of GR-S containing microgel (conversion 74.7 and 81.5 per cent). There was no appreciable difference in the amount of sorption of rubber fractions having average molecular weights varying from 433,000 to 85,000. There is little change in the amount sorbed after two hours of shaking, but the intrinsic viscosity of the residual rubber decreases with time. The low molecular-weight rubber is sorbed more rapidly, but is slowly replaced by the more tightly sorbed high molecular weight fraction. Partial fractionation of a rubber sample can be achieved by allowing the rubber solution to flow through a column of weakly sorbing carbon black. A large portion of the sorbed rubber can be recovered from the column by washing it with a good solvent such as xylene. Bound rubber is produced by intimate mixing of equal parts of carbon black and rubber swollen in chloroform, when the mixture is dried in vacuum at 80° or at room temperature. Milling is not essential to get bound rubber.

scholarly journals Synthesis and Characterization of a Fe3O4@PNIPAM-Chitosan Nanocomposite and Its Potential Application in Vincristine Delivery

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1704
Author(s):  
Cynthia N. Hernández-Téllez ◽  
Ana G. Luque-Alcaraz ◽  
Maribel Plascencia-Jatomea ◽  
Hiram J. Higuera-Valenzuela ◽  
Mabeth Burgos-Hernández ◽  
...  
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Release Kinetics ◽  
Magnetic Core ◽  
Systematic Evaluation ◽  
Solution Temperature ◽  
Core Shell ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Thermomagnetic Properties ◽  
Release Model

In this research, we conducted a systematic evaluation of the synthesis parameters of a multi-responsive core-shell nanocomposite (Fe3O4 nanoparticles coated by poly(N-isopropylacrylamide) (PNIPAM) in the presence of chitosan (CS) (Fe3O4@PNIPAM-CS). Scanning electron microscopy (SEM) was used to follow the size and morphology of the nanocomposite. The functionalization and the coating of Fe3O4 nanoparticles (Nps) were evaluated by the ζ-potential evolution and Fourier Transform infrared spectroscopy (FTIR). The nanocomposite exhibited a collapsed structure when the temperature was driven above the lower critical solution temperature (LCST), determined by dynamic light scattering (DLS). The LCST was successfully shifted from 33 to 39 °C, which opens the possibility of using it in physiological systems. A magnetometry test was performed to confirm the superparamagnetic behavior at room temperature. The obtained systems allow the possibility to control specific properties, such as particle size and morphology. Finally, we performed vincristine sulfate loading and release tests. Mathematical analysis reveals a two-stage structural-relaxation release model beyond the LCST. In contrast, a temperature of 25 °C promotes the diffusional release model. As a result, a more in-depth comprehension of the release kinetics was achieved. The synthesis and study of a magnetic core-shell nanoplatform offer a smart material as an alternative targeted release therapy due to its thermomagnetic properties.

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