SEMICONTINUOUS HETEROPHASE POLYMERIZATION AS A TOOL FOR PREPARING ULTRAFINE NANOPARTICLES OF IBUPROFEN-POLY(METHYL METHACRYLATE)

NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450060 ◽  
Author(s):  
HENED SAADE ◽  
JESUS CEPEDA GARZA ◽  
MARIA LUISA LOPEZ-QUINTANILLA ◽  
FRANCISCO ENRIQUEZ-MEDRANO ◽  
SALVADOR FERNANDEZ ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Average Diameter ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Heterophase Polymerization ◽  
Hydrophobic Polymers ◽  
Scanning Transmission ◽  
Insoluble Drugs ◽  
20 Nm ◽  
Semicontinuous Heterophase Polymerization

Ibuprofen-loaded poly(methyl methacrylate) nanoparticles with mean diameters smaller than 20 nm were prepared by a novel method. This consists in carrying out a semicontinuous heterophase polymerization, in which a solution of drug-monomer is added on a micellar solution at an appropriate dosing rate. Scanning transmission electron microscopy (STEM) measurements showed number-average diameters in the range 16–19 nm with 1.14–1.15 in polydispersity, determined as the ratio of weight-average to number-average diameter. Drug contents in nanoparticles close to 24% were determined by UV-Vis spectrophotometry, confirming the results obtained from a procedure that combines latex filtration and quasielastic light scattering (QLS) measurements. Differential scanning calorimetry (CDSC) determinations suggest that at the ibuprofen contents attained in this study, crystals and dispersed molecules of the drug coexist inside the nanoparticles. Based on the relative simplicity of the process it is expected that its use will be adopted to prepare ultrafine nanoparticles composed of different hydrophobic polymers and water insoluble drugs.

Narrow size-distribution poly(methyl methacrylate) nanoparticles made by semicontinuous heterophase polymerization

2010 ◽  
Vol 119 (3) ◽  
pp. 1827-1834 ◽  
Author(s):  
J. Aguilar ◽  
M. Rabelero ◽  
S. M. Nuño-Donlucas ◽  
E. Mendizábal ◽  
A. Martínez-Richa ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Size Distribution ◽  
Narrow Size Distribution ◽  
Poly Methyl Methacrylate ◽  
Heterophase Polymerization ◽  
Semicontinuous Heterophase Polymerization

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

2021 ◽  
pp. 096739112110147
Author(s):  
Ufuk Abaci ◽  
H Yuksel Guney ◽  
Mesut Yilmazoglu
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Dielectric Properties ◽  
Methyl Methacrylate ◽  
Pure Pmma ◽  
Segmental Mobility ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Casting Technique ◽  
Lcr Meter

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate)

2018 ◽  
Vol 36 (6) ◽  
pp. 495-504 ◽  
Author(s):  
Sunil S Suresh ◽  
Smita Mohanty ◽  
Sanjay K Nayak
Keyword(s):  
Methyl Methacrylate ◽  
Vinyl Chloride ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Poly Methyl Methacrylate ◽  
Impact Performance ◽  
Acrylonitrile Butadiene Rubber ◽  
Poly Vinyl Chloride ◽  
Spectroscopy Studies

The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

Characterizations of Multiphase Biogenic Polymer Blends from Poly(L-lactide) and Poly(methyl methacrylate)

2005 ◽  
Vol 897 ◽  
Author(s):  
Kim-Phuong Nguyen Le ◽  
Richard Long Lehman ◽  
Kenneth VanNess ◽  
James D Idol
Keyword(s):  
Methyl Methacrylate ◽  
Melt Processing ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Binary Blends ◽  
Poly Methyl Methacrylate ◽  
New Material ◽  
Superior Mechanical Properties ◽  
Interconnected Structure

AbstractMelt processing of binary immiscible polymer systems has been a focus of our group as an economical and scalable route to achieve synergistic or superior mechanical properties at and around the co-continuous region without the need of compatibilization. System of poly(L-lactide) (PLLA) and poly(methyl methacrylate) (PMMA) was selected to target bio-related applications, including bone fillers and scaffolds, where the biodegradability of PLLA will enable the integration of native tissue into the material over time. Tunable properties such as morphology, interconnectivity, resorbability and interfacial bonding control the long-term integrity of the new material and influence the interaction and integration of new tissue. Binary blends of PLLA and PMMA has been prepared and characterized over a large range of compositions in which regions of co-continuity are of special interest. Such regions exhibit a well interconnected structure that ensures controlled release of resorbable PLLA. Modulated differential scanning calorimetry (MDSC) detected a broad and unexpected transition between 70 °C and 100 °C. The magnitude of this transition is greatest within co-continuous regions, suggesting the presence of a complex or other derivative of the two primary phases. This complex appears to provide a degree of compatibilization between the phases, thus inducing mechanical property synergism which has been confirmed by flexural and nano-indentation analyses.

ELECTRICAL CONDUCTIVITY AND DIELECTRIC RELAXATION STUDY OF POLYVINYL ACETATE/POLY METHYL METHACRYLATE BLENDS

2012 ◽  
Vol 26 (29) ◽  
pp. 1250159 ◽  
Author(s):  
R. M. AHMED
Keyword(s):  
Electrical Conductivity ◽  
Methyl Methacrylate ◽  
Conduction Mechanism ◽  
Polyvinyl Acetate ◽  
Qualitative Description ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Casting Technique ◽  
Transparent Films ◽  
Tan Δ

Transparent films of PMMA (poly methyl methacrylate), PVAc (polyvinyl acetate) and their blends, have been prepared by using a solution-casting technique. The dielectric properties and the electrical conductivity are reported. The frequency and temperature dependence of the dielectric constant, ε′ and tan δ, have been investigated for the studied samples in the frequency range from 1 kHz to 5 MHz and over a range of temperature from 303–413 K. In addition, AC conductivity values were calculated from the dielectric data and the conduction mechanism is discussed. The frequency-dependent conductivity behavior at different temperatures provides a qualitative description of the conduction mechanism. Also, differential scanning calorimetry (DSC) scans have been measured for the studied samples.

scholarly journals Chromaticity Properties of Curcuminoids Dye Nanofibers Prepared by Electrospinning for White Light Down-Conversion

2020 ◽  
Vol 301 ◽  
pp. 77-84
Author(s):  
M. Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
Methyl Methacrylate ◽  
White Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Average Diameter ◽  
Color Temperature ◽  
Light Emitting ◽  
Poly Methyl Methacrylate ◽  
Color Rendering ◽  
Down Conversion

In this study, the chromaticity properties of curcuminoids nanofibers were studied. Recent studies revealed that the nature of emitted light from curcuminoids and the poor stability which limits their illumination applications can be further improved using nanofibers and nanoparticles of curcuminoids. Motivated by this idea, we prepared some Poly(methyl methacrylate) (PMMA) integrated curcuminoids nanofibers via electrospinning. Poly(methyl methacrylate) (PMMA) were used in three types of concentration (5,10 and15wt%) which were mixed with (curcuma longa L.) powder to produce curcuminoids solution by using the centrifuge to separate the curcuminoids solution from the impurities. Different amounts of polymer solution mixed with curcuminoids (1 to 5ml) were spun by electrospinning to study its properties. The effect of annealing on samples was studied. The chromatic study of the samples and the effect of the amount and concentration of the solution were studied by pumping the samples in three different light emitting diode (LED) wavelengths (365, 390 and 445nm). The white light chromaticity coordinates (CIE), correlated color temperature (CCT) and color rendering index (CRI) were measured. The optimum CIE, CRI and CCT values of (X= 0.3051; Y= 0.3370), 64 and 6809K, respectively were obtained. By using field emission scanning electron microscope (FESEM) device, the curcuminoids nanofibers diameter was measured, where the values obtained ranged between 191 to 234nm. After the annealing process, curcuminoids nanoparticles average diameter 13-19 nm were obtained.

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