Recycling Scrap Crosslinked Urethane Polymers

1975 ◽  
Vol 48 (5) ◽  
pp. 972-980 ◽  
Author(s):  
R. M. Gerkin ◽  
F. E. Critchfield ◽  
W. A. Miller ◽  
R. Roberts ◽  
C. G. Seefried
Keyword(s):  
Particle Size ◽  
Ambient Temperature ◽  
Size Reduction ◽  
Minor Effect ◽  
Particle Size Reduction ◽  
Foam Formulation ◽  
A Minor ◽  
High Degree ◽  
Sulfur Curing

Abstract A. Scrap LRM polymers can be ground to powder on the Banbury operating at ambient temperature with cooling of the rotors and jacket. Particle size reduction can be accomplished in 5 min at 180 rpm. B. Powdered LRM polymer can be blended with TPU up to 50 wt.% and the composite compression molded to give the same properties as the TPU. C. Powdered LRM polymer can be blended with nitrile, chloroprene, and EPDM rubbers to give incompatible composites. The powdered LRM polymer acts in a manner similar to typical nonreinforcing fillers. D. It is possible to degrade powdered LRM polymers to a tacky mass at 180°C, which behaves much like a typical extender oil, when blended with nitrile and chloroprene rubbers. It is speculated that the degraded urethane should show a high degree of permanency in such blends. E. Addition of the urethane polymer to the rubber stocks does not interfere with the standard sulfur-curing mechanisms. F. Scrap HR foam can be ground to a powder in the Banbury in a manner similar to LRM scrap. G. A blend of 5 phr of powdered foam with a new HR foam formulation was machine processable. Addition of the powder had only a minor effect on the properties of the new foam.

Methods for particle size reduction of liposomal amphotericin B

2018 ◽  
Vol 60 (1) ◽  
pp. 42-45
Author(s):  
Tuan Quang Nguyen ◽  
Van Lam Nguyen ◽  
Thai Son Nguyen ◽  
Thi Minh Hue Pham ◽  
◽  
...  
Keyword(s):  
Particle Size ◽  
Amphotericin B ◽  
Liposomal Amphotericin ◽  
Size Reduction ◽  
Liposomal Amphotericin B ◽  
Particle Size Reduction

scholarly journals Laser Superficial Fusion of Gold Nanoparticles with PEEK Polymer for Cardiovascular Application

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak
Keyword(s):  
Particle Size ◽  
Laser Beam ◽  
Gold Particle ◽  
Laser Power ◽  
Biomedical Application ◽  
Parameters Optimization ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Nano Gold ◽  
Gold Particle Size

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.

scholarly journals Characterization of Astaxanthin Nanoemulsions Produced by Intense Fluid Shear through a Self-Throttling Nanometer Range Annular Orifice Valve-Based High-Pressure Homogenizer

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2856
Author(s):  
Gary B. Smejkal ◽  
Edmund Y. Ting ◽  
Karthik Nambi Arul Nambi ◽  
Richard T. Schumacher ◽  
Alexander V. Lazarev
Keyword(s):  
Particle Size ◽  
Size Reduction ◽  
Hydrodynamic Diameter ◽  
Fluid Shear ◽  
Particle Size Reduction ◽  
Annular Gap ◽  
Oil In Water ◽  
High Pressure Homogenizer ◽  
Pass Through

Stable, oil-in-water nanoemulsions containing astaxanthin (AsX) were produced by intense fluid shear forces resulting from pumping a coarse reagent emulsion through a self-throttling annular gap valve at 300 MPa. Compared to crude emulsions prepared by conventional homogenization, a size reduction of over two orders of magnitude was observed for AsX-encapsulated oil droplets following just one pass through the annular valve. In krill oil formulations, the mean hydrodynamic diameter of lipid particles was reduced to 60 nm after only two passes through the valve and reached a minimal size of 24 nm after eight passes. Repeated processing of samples through the valve progressively decreased lipid particle size, with an inflection in the rate of particle size reduction generally observed after 2–4 passes. Krill- and argan oil-based nanoemulsions were produced using an Ultra Shear Technology™ (UST™) approach and characterized in terms of their small particle size, low polydispersity, and stability.

scholarly journals Sonocrystallization—Case Studies of Salicylamide Particle Size Reduction and Isoniazid Derivative Synthesis and Crystallization

Crystals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 249 ◽  
Author(s):  
Zhen-Yu Yang ◽  
Shih-Kuo Yen ◽  
Wei-Syun Hu ◽  
Yu-Zhe Huang ◽  
Tsung-Mao Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Case Studies ◽  
Size Reduction ◽  
Particle Size Reduction

Substrate particle size reduction by Bacillus coagulans in solid-state fermentation

1996 ◽  
Vol 18 (2) ◽  
pp. 121-125 ◽  
Author(s):  
M.P. Nandakumar ◽  
M.S. Thakur ◽  
K.S.M.S. Raghavarao ◽  
N.P. Ghildyal
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Solid State Fermentation ◽  
Bacillus Coagulans ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Substrate Particle

Liquid antisolvent recrystallization and solid dispersion of flufenamic acid with polyvinylpyrrolidone K-30

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rahul Kumar ◽  
Sanjay Kumar ◽  
Pranava Chaudhari ◽  
Amit K. Thakur
Keyword(s):  
Particle Size ◽  
Dissolution Rate ◽  
Solid Dispersion ◽  
Fine Particles ◽  
Xrd Analysis ◽  
Solution Concentration ◽  
Injection Rate ◽  
Size Reduction ◽  
Flufenamic Acid ◽  
Particle Size Reduction

Abstract Flufenamic acid (FFA) is a Biopharmaceutical Classification System- II (BCS-II) class drug with poor bioavailability and a lower dissolution rate. Particle size reduction is one of the conventional approaches to increase the dissolution rate and subsequently the bioavailability. The use of the liquid antisolvent method for particle size reduction of FFA was studied in this work. Ethanol and water were used as solvent and antisolvent, respectively. Experimental parameters such as solution concentration (10–40 mg/ml), flow rate (120–480 ml/h), temperature (298–328 K) and stirring speed (200–800 rpm) were investigated. Furthermore, the solid dispersion of FFA was prepared with polyvinylpyrrolidone K-30 (PVP K-30) with different weight ratios (1:1, 1:2, 1:3 and 1:4) and samples were characterized using SEM, FTIR and XRD techniques. The experimental investigation revealed that higher values of concentration, injection rate, stirring speed, along with lower temperature favored the formation of fine particles. SEM analysis revealed that the morphology of raw FFA changed from rock-like to rectangular-like after liquid antisolvent recrystallization. FTIR analysis validated the presence of hydrogen bonding between FFA and PVP in solid dispersion. XRD analysis showed no significant change in the crystallinity of the processed FFA.

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