Supercritical carbon dioxide-assisted solid-phase free radical grafting of butyl acrylate onto PP

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Wang Jian ◽  
Wang Deng-Fei ◽  
Du Wei ◽  
Zou En-Guang ◽  
Dong Qun
Keyword(s):  
Free Radical ◽  
Butyl Acrylate ◽  
Solid Phase ◽  
Particle Diameter ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Experimental Conditions ◽  
Water Contact ◽  
Melt Flow Rate ◽  
Grafting Reaction

AbstractFree radical grafting copolymerization of butyl acrylate (BA) onto polypropylene (PP) matrix was investigated using supercritical CO2 as a swelling agent and carrier solvent. The monomer BA and initiator AIBN were first dissolved in supercritical CO2, and then these small molecules were diffused into the grafting zones of PP matrix. As grafting reaction temperature (about 80 °C) was far below the melting point, PP was modified in the solid phase. The effects of different experimental conditions such as soaking time and temperature, supercritical CO2 pressure; monomer and initiator concentration; PP particle diameter; solid phase grafting reaction time and temperature on grafting percentage were studied. Fourier transform infrared spectroscopy (FTIR) results and gel content experiment prove that the monomers were indeed grafted onto PP chains. Scanning electron microscope (SEM) analysis of the grafted sample indicates that the grafting branches PBA were homogeneously distributed onto the surfaces and micropores of PP particles. Thermal gravimetric analysis (TGA) results show that the grafted samples had a higher onset thermal degradation temperature and a lower weight loss at a particular temperature than pure PP. The water contact angle of PP-g-BA decreased from 98° to 72°, indicating the polarity and hydrophilicity of PP were improved effectively. The melt flow rate (MFR) and mechanical analysis results show that the grafting sample remained its versatile physical properties though introducing the grafting BA branch chain. This is prominent when it was compared with normal solid grafting product.

scholarly journals Efficient approach to produce functional polypropylene via solvent assisted solid-phase free radical grafting of multi-monomers

2021 ◽  
Author(s):  
Dengfei Wang ◽  
Jian Wang ◽  
Shuyan He ◽  
Yibin Yan ◽  
Jianwei Zhang ◽  
...  
Keyword(s):  
Free Radical ◽  
Flow Rate ◽  
Solid Phase ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
X Ray Diffraction ◽  
Water Contact ◽  
Melt Flow Rate ◽  
Efficient Approach ◽  
Polar Species

AbstractHerein an efficient approach to produce functional polypropylene via solvent assisted solid-phase grafting process is reported, in which acrylic acid, methyl methacrylate and maleic anhydride are used as multi-monomers, 2,2′-azobis(2-methylpropionitrile) as initiator and ether as swelling solvent and carrier. The effects of various factors such as the swelling solvent species and dosage, swelling time and temperature, monomer and initiator concentrations, reaction time and temperature, nitrogen flow rate and the stirring speed on the grafting percentage and grafting efficiency were investigated. To verify the polar species was grafted onto polypropylene, the resulted polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, water contact angle measurement, tensile strength and melt flow rate measurement. All the results showed that using the ether assisted solid-phase free radical grafting process is an efficient and versatile approach to produce functional polypropylene.

Synthesis of [1-β-mercaptopropionic acid, 8-D-arginine]vasopressin (DDAVP) in solid phase. Simple optimalization

1979 ◽  
Vol 44 (4) ◽  
pp. 1173-1178 ◽  
Author(s):  
Viktor Krchňák ◽  
Milan Zaoral
Keyword(s):  
Arginine Vasopressin ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Experimental Conditions ◽  
Phase Synthesis ◽  
Mercaptopropionic Acid ◽  
Better Than

A series of solid-phase syntheses of the protected precursor II of DDAVP was carried out. Experimental conditions were developed under which practically pure II can reproducibly be obtained in yields better than 60%. The protected precursors of DDAVP obtained by liquid- and solid-phase synthesis and DDAVP samples obtained from these precursors were undistinguishable by conventional analytical or pharmacological assays.

Physico Chemical Characterization of Nanofibrous Poly(Ε-Caprolactone) Electrospun Templates for Cell Adhesion

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2689-2694
Author(s):  
Karla A. Gaspar-Ovalle ◽  
Juan V. Cauich-Rodriguez ◽  
Armando Encinas
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cell Adhesion ◽  
Tensile Modulus ◽  
Chemical Characterization ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Physico Chemical ◽  
Static Water

ABSTRACTNanofibrous mats of poly ε-caprolactone (PCL) were fabricated by electrospinning. The nanofiber structures were investigated and characterized by scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, static water-contact-angle analysis and mechanical properties. The results showed that the nanofibrous PCL is an ideal biopolymer for cell adhesion, owing to its biocompatibility, biodegradability, structural stability and mechanical properties. Differential scanning calorimetry results showed that the fibrous structure of PCL does not alter its crystallinity. Studies of the mechanical properties, wettability and degradability showed that the structure of the electrospun PCL improved the tensile modulus, tensile strength, wettability and biodegradability of the nanotemplates. To evaluate the nanofibrous structure of PCL on cell adhesion, osteoblasts cells were seeded on these templates. The results showed that both adhesion and proliferation of the cells is viable on these electrospun PCL membranes. Thus electrospinning is a relatively inexpensive and scalable manufacturing technique for submicron to nanometer diameter fibers, which can be of interest in the commodity industry.

Influence of biomass on hydrodynamics of an internal loop airlift reactor

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
M. Juraščík ◽  
M. Hucík ◽  
I. Sikula ◽  
J. Annus ◽  
J. Markoš
Keyword(s):  
Aspergillus Niger ◽  
Gluconic Acid ◽  
Solid Phase ◽  
Biomass Concentration ◽  
Airlift Reactor ◽  
Phase System ◽  
Two Phase ◽  
Experimental Conditions ◽  
Internal Loop ◽  
Three Phase

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

Consolidation Features of Aluminum-Alumina Compositions by Powder Metallurgy Methods

2016 ◽  
Vol 254 ◽  
pp. 110-115
Author(s):  
Mihai Ovidiu Cojocaru ◽  
Mihaela Raluca Condruz ◽  
Florică Tudose
Keyword(s):  
Solid Phase ◽  
Particle Diameter ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Average Particle ◽  
Matrix Composites ◽  
Aluminum Particles ◽  
Transmission Electron ◽  
Tapped Density ◽  
Powder Metallurgy Methods

In this paper was followed the processing flow of aluminum-alumina compositions (10÷20% alumina) in powder state, aiming to obtain aluminum matrix composites reinforced with alumina particles, starting from selecting and mixing the grading fraction of both components reaching up to sintering; it was analyzed the way in which reflects the variation of grading fraction ratio (expressed through average particle diameter in the analyzed fractions limits) on the level of technological interest features: apparent density, tapped density, flowability, presability and on densification after sintering (in various environments). By transmission electron microscopy was observed that aluminum particles showed on the surface a nanoscale oxide film, so the sintering occurs between congeneric areas – by solid phase sintering mechanisms [1, 2, 3]. The analysis of thermophysical properties revealed a decrease of thermal diffusivity at an increase of alumina, simultaneous with the decrease of the densification level.

scholarly journals Bioactivity of extracts of Centaurea polyclada dc. (Asteraceae)

2009 ◽  
Vol 61 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Melanie Granger ◽  
Emilie Samson ◽  
Severine Sauvage ◽  
Anisha Majumdar ◽  
Poonam Nigam ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Free Radical ◽  
Solid Phase Extraction ◽  
Brine Shrimp ◽  
Solid Phase ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Phase Extraction ◽  
Brine Shrimp Lethality Assay

The free radical-scavenging property, antibacterial activity, and brine shrimp toxicity of n-hexane, dichloromethane (DCM), and methanol (MeOH) extracts of Centaurea polyclada, an endemic Turkish species, were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtiter plate-based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts of C. polyclada exhibited free radical-scavenging ability with RC50 values 1.17 and 0.015 mg/mL, respectively. Among solid-phase extraction fractions of the MeOH extract, the fraction eluted with 60% MeOH in water demonstrated the highest level of free radical-scavenging activity (RC50 = 0.016 mg/mL). Only the DCM extract showed considerable antibacterial activity against all nine test strains except Escherichia coli, with MIC ranging from 1.25 to 2.50 mg/mL. This antibacterial activity pattern was also observed with solid-phase extraction fractions of the DCM extract with varied potencies. None of the extracts showed any significant toxicity towards brine shrimps (LD50 = >1.00 mg/mL).

scholarly journals Manganese carbonate-zinc glycerolate, synthesis, characterization and application as catalyst for transesterification of soybean oil

2016 ◽  
Vol 22 (4) ◽  
pp. 431-443
Author(s):  
Xiaochan Zhu ◽  
Hui Liu ◽  
Dejan Skala
Keyword(s):  
Soybean Oil ◽  
Solid Phase ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Mixed System ◽  
Solid Catalyst ◽  
Manganese Carbonate ◽  
Gravimetric Analysis ◽  
Working Parameters

In this study, mixed system containing manganese carbonate (MnCO3) and zinc glycerolate (ZnGly) was synthesized, and tested as solid catalyst for transesterification of soybean oil and biodiesel production. The samples of MnCO3/ZnGly before and after usage for transesterification process were characterized using different techniques: determination of basic strength, determination of specific surface area according to Brunauer-Emmett-Teller (BET), measuring the mass change using thermal gravimetric analysis (TGA), investigating the solid phase content and presence of different specific elements and groups by X-Ray diffraction (XRD), the Fourier transform infrared (FT-IR) spectroscopy, the scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The effects of different working parameters of transesterification were also investigated: temperature (438-458K), duration of transesterification (0-3.5h), methanol to oil molar ratio (12:1-36:1) and used amounts of catalyst (1-5 mass%). The reusability and stability of MnCO3/ZnGly were analyzed and obtained results showed that MnCO3/ZnGly exhibited a good activity with 100% TG conversion and 81.5% FAME yield with fresh catalyst, and can give 95-100% TG conversion and 62-78% FAME yield after 13 repeated use of same amount of catalyst without regeneration processes. Content of Mn and Zn in biodiesel and glycerol was analyzed by ICP-AAS after each reuse of catalyst.

Novel Enhanced Acrylic Denture Base Powder by Incorporating with PMMA-Modified Ag/NaZr2(PO4)3 through In Situ Suspension Polymerization

2015 ◽  
Vol 815 ◽  
pp. 342-347
Author(s):  
Jun Jun Du ◽  
Hao Yu ◽  
Mei Fang Zhu
Keyword(s):  
Suspension Polymerization ◽  
Flexural Properties ◽  
Powder Size ◽  
Gravimetric Analysis ◽  
Water Contact ◽  
Denture Base ◽  
Base Powder ◽  
Base Resin ◽  
Denture Base Resin

A kind of novel antibacterial denture base powder incorporated with PMMA-modified nanoAg/NaZr2(PO4)3(CBD-300) was prepared by in-situ suspension polymerization and the flexural properties of denture base resin was investigated. CBD-300 was silanized by 3-methacryloxy propyl trimethoxyl silane (γ-MPS), and thenγ-MPS-CBD-300 was grafted with poly (methyl methacrylate) (PMMA) to prepare M-CBD-300 which has a good compatibility with the denture base resin. Denture base powders with different addition of M-CBD-300 were prepared by in-situ suspension polymerization. Thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and water contact angle were used to characterize M-CBD-300. The size of denture base powder was observed by optical microscope. Universal testing apparatus and scanning electron microscope (SEM) were used to investigate flexural properties of denture base resin samples. The results showed that the surface of M-CBD-300 was successfully modified by PMMA, and the incorporation of M-CBD-300 leads to increasing of the denture base powder size. The flexural properties of the denture base resin samples prepared with our antibacterial denture base powders were enhanced greatly compared with the blank sample.

Solid-Phase Free Radical Addition of Thiols to Allyl Ethers

Synlett ◽  
2001 ◽  
Vol 2001 (03) ◽  
pp. 0439-0441 ◽  
Author(s):  
Robert Plourde ◽  
Leland L. Johnson ◽  
Rachel K. Longo
Keyword(s):  
Free Radical ◽  
Solid Phase ◽  
Radical Addition ◽  
Allyl Ethers ◽  
Free Radical Addition

scholarly journals Preparation and Component Optimization of Resin-Based Permeable Brick

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2701
Author(s):  
Xiaofu Wang ◽  
Xiong Zhang
Keyword(s):  
Particle Diameter ◽  
Characteristic Parameter ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Fine Aggregate ◽  
Test Results ◽  
Dynamic Mechanical ◽  
Aggregate Distribution ◽  
Particle Group ◽  
Selection Of

The present study aims to prepare resin-based permeable bricks with micron-sized pores using fine aggregate with a particle diameter of 0.08–0.6 mm and bisphenol-A epoxy resin, a polymer binder. The properties of the binder, the characteristic parameters of the aggregate, and the micro pore structure of the brick were studied in order to break through the limitations of traditional porous permeable materials. The dynamic mechanical properties of resin were analyzed by dynamic mechanical analysis (DMA). The frequency parameter of particle size of 10 kinds of aggregate from different regions were obtained by digital image processing, and the characteristic parameter (aggregate distribution coefficient α) was obtained by modified Gaussian distribution. The microstructure of porous brick was analyzed by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The test results show: (1) the glass transition temperature (Tg) of the resin is 61 °C; (2) the parameters of aggregate particle group will affect the performance of porous permeable materials; (3) the minimum effective pore diameter of the permeable brick is 30 μm, the maximum permeable rate is 6.22 × 10 − 2   cm / s and the compressive strength is 41.08 MPa. The conclusions of this study will provide an important reference for permeable materials in the micron-scale pore range and the selection of binder and aggregate materials.

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