Preparation and Characterization of Magnetic Toner Particles by Direct Polymerization Method

2011 ◽  
Vol 217-218 ◽  
pp. 1702-1707
Author(s):  
Yu Feng Duan ◽  
Zhao Xia Fu
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Influence Factor ◽  
Suspension Polymerization ◽  
Spherical Surface ◽  
Crosslinking Agent ◽  
Polymerization Process ◽  
Stirrer Speed ◽  
Sem Image ◽  
Polymerization Method

In this study a kind of black toner, containing polymer, magnetic iron oxide pigment, and several other additives, was prepared by a suspension polymerization method. The morphology, influence factor of particle size, and glass transition of prepared toner were discussed. SEM image showed that the produced micron-sized particles have a spherical surface and the various chemicals were mixed into monomers during manufacturing of the particles. Discussion about particle formation and stability concluded that the toner particle size related with stabilizer concentration, stirrer speed, and crosslinking agent concentration. The bigger particles, resulted from droplets coalescence during polymerization process, disappeared when enough PVA stabilizer was used in the aqueous medium. .Increasing the stirrer speed corresponded to the decrease of the particles size. But any increase in stirrer speed t did not contribute to size reduction in small particles below 2μm. It was found that particle size decrease with the addition of crosslinking agent. The DSC result indicated the glass transition of polymerized toner could be effectively adjusted according to Fox equation through change the monomer ratio.

Effect of Particle Size of Natural Based Carbon Filler to the Absorbency of Superabsorbent Polymer Composite Synthesis by Graft Polymerization Method

2015 ◽  
Vol 1119 ◽  
pp. 301-305
Author(s):  
Wan Siti Nadiah Wan Yaacoba ◽  
Saidatul Shima Jamarib ◽  
Suriati Ghazalic
Keyword(s):  
Particle Size ◽  
Graft Polymerization ◽  
Crosslinking Agent ◽  
Superabsorbent Polymer ◽  
Electron Microscopic ◽  
Carbon Filler ◽  
Sem Image ◽  
Degree Of Swelling ◽  
Natural Carbon ◽  
Polymerization Method

Superabsorbent polymer (SAP) has been widely used in many application such as in hygiene products, agriculture and also horticulture, wastewater treatment and others. The absorbency and degradability of SAP can be enhanced by utilization of carbon filler. In this research, SAP with carbon filler has been synthesized using graft polymerization method. Acrylic acid (AA) used as monomer, N, N-methylbisacrylamide (MBA) used as crosslinking agent, ammonium persulphate (APS) as initiator and different size of natural carbon filler used as filler. Water absorbency test showed that SAP with 500 μm carbon filler has highest degree of swelling while SAP with 125 μm and 71 μm carbon filler has degree of swelling lower than degree of swelling of control hydrogel. Scanning electron microscopic (SEM) image showed 500 μm carbon filler has better surface morphology and alignment to make interfacial contact with hydrogel besides buil excellent capillary effect to absorb and store more water. In conclusion, smaller in particle size of filler will decrease the degree of swelling of SAP.

scholarly journals Effect of the operating conditions on the particle size distribution by the suspension polymerization process

2019 ◽  
pp. 1-12
Author(s):  
José Josué Rodríguez-Pizano ◽  
Laura Edith Granados-Rivera ◽  
Héctor Hernández-Escoto ◽  
David Contreras-López
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Free Radical ◽  
Suspension Polymerization ◽  
Agitation Speed ◽  
Operating Conditions ◽  
Polymerization Process ◽  
Dispersing Agent ◽  
Suspension Process ◽  
Reaction Performance

In this research, we focus on the study of the operating conditions that influence on suspension process for obtaining (co)polymers of styrene with polar monomers (copolymers of styrene with acrylate of butyl (S-BA) and copolymers of styrene with vinyl acetate (S-VAc)) using the technique of conventional free radical polymerization (FRP). At higher agitation speed, the reaction performance decreases. Likewise, the influence of the molecular weight of the dispersing agent, in this case polyvinyl alcohol (PVA), influences the polymerization performance was also observed. That is, at a higher molecular weight of PVAs, there is an increase in the particle size of the bead and in the polymerization yield. Finally, there is an influence of the polar part on the copolymer both for the yield and for the particle size of the bead. When obtaining copolymers of S-VAc, the yield is lower compared to the respective styrene homopolymer and higher in the S-BA.

Synthesis and Humidity Controlling Properties of Hydrotalcite/poly (sodium acrylate-acrylamide) Composite

2011 ◽  
Vol 374-377 ◽  
pp. 1420-1425
Author(s):  
Ji Hui Wang ◽  
Fei Dong ◽  
Shu Ping Ren ◽  
Meng Jie Guo
Keyword(s):  
Surface Morphology ◽  
Suspension Polymerization ◽  
Polymerization Process ◽  
Sodium Acrylate ◽  
Inverse Suspension Polymerization ◽  
Orthogonal Experiments ◽  
Controlling Behavior ◽  
Acrylamide Monomers ◽  
The Impact ◽  
Polymerization Method

Hydrotalcite/poly(sodium acrylate-acrylamide) composite was synthesized by using inverse suspension polymerization method under different hydrotalcite content, neutralization degree and ratio of monomer with orthogonal experiments. The surface morphology, structure and humidity controlling properties of composite were observed and determined. The results show that hydrotalcite/poly (sodium acrylate-acrylamide) composite is in an irregular block like structure with different size. During the polymerization process, acrylate and acrylamide monomers are successfully intercalated into the interlayer of hydrotalcite, and the distance of (003) hydrotalcite plane is increased from 0.766nm to 1.146nm. The impact of three factors on the humidity controlling behavior of composites increases by the order of ratio of monomer, hydrotalcite content and neutralization degree. The optimum preparation parameters are hydrotalcite content of 4%, neutralization degree of 90% and ratio of monomer in 9:1.

New Hypercrosslinked Polymer Adsorbents for Solid Phase Extraction of Polar Compounds

2011 ◽  
Vol 239-242 ◽  
pp. 2076-2079 ◽  
Author(s):  
Qing Zhou ◽  
Man Cheng Zhang ◽  
Zhe Qin Li ◽  
Ai Min Li
Keyword(s):  
Particle Size ◽  
Solid Phase Extraction ◽  
Small Particle ◽  
Solid Phase ◽  
Suspension Polymerization ◽  
Polar Compounds ◽  
Phase Extraction ◽  
Large Specific Surface Area ◽  
Small Particle Size ◽  
Polymerization Method

Membrane emulsification-suspension polymerization method was introduced to prepare the monodisperse hypercrosslinked adsorbents ZQ-1 and ZQ-2 which can be used in solid phase extraction (SPE). Compared with the commercially available adsorbent LichrolutEN, ZQ-1 exhibits obvious superiority for five conventional polar analytes owing to its large specific surface area, hydrophilic groups and small particle size.

scholarly journals The Effects of Initiators Mixture on Suspension Polymerization of Vinyl Chloride and its Comparison with other Productivity-Enhancing Procedures

2018 ◽  
Author(s):  
Reza Darvishi ◽  
Aref Shahi
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Vinyl Chloride ◽  
Suspension Polymerization ◽  
Three Dimensional ◽  
Control Process ◽  
Morphological Properties ◽  
Polymerization Process ◽  
Sem Images

Molecular and morphological properties of poly(vinyl chloride) grains produced by suspension polymerization of VCM in the presence of a mixture of three kind of initiators (i.e. fast, mild and slow) (named as Cok process) was experimentally investigated in a pilot-scale reactor. The results obtained here were initially compared with a isothermal regular process (named as control process) and then with those obtained already for other productivity-enhancing polymerization techniques (i.e. nonisothermal and fast initiator dosage process). The results showed that, in contrast to nonisothermal and fast initiator dosage process, the addition of initators mixture at the beginning of the reaction has the smallest influence on molecular weight and polydispersity index compared to control process. It is obvioused that Cok-PVC grains have the lowest cold plasticizer absorption and porosity among these mentioned processes. Scanning electron microscopy (SEM) showed that the particles produced by Cok process are more regularly shaped, with a smoother surface compared with the control product. According to the literatures, all three productivity-enhancing techniques lead to an apparent quality enhancement, higher flowability and greater bulk density of final grains. While both processes of continous initiator dosage and nonisothermal polymerization broaden the particle size distribution of final PVC grains, applying initiator mixture produces particles with the same particle size distribution as control process. The SEM images processing showed that Cok process deccelerates the formation of a three-dimensional skeleton of primary particles relative to the control polymerization. In comparison with nonisothermal trajectory and continous fast initiator dosage system, the Cok polymerization process leads to the most delay of motionless conversions and fusion time as well.

Preparation of ZrO2(f)/PMMA-PMA Composites by a Suspension Polymerization Process

2008 ◽  
Vol 368-372 ◽  
pp. 1221-1223 ◽  
Author(s):  
Bin Zheng ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Jian Peng Wu
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Methyl Methacrylate ◽  
Methyl Acrylate ◽  
Suspension Polymerization ◽  
Volume Ratio ◽  
Polymerization Process ◽  
Mass Ratio ◽  
Zirconia Fiber ◽  
Polymerization Method

Yttria stabled zirconia fiber reinforced polymethyl methacrylate-polymethyl acrylate (PMMAPMA) composites (ZrO2(f)/PMMA-PMA) were prepared by a suspension polymerization method. The effects of MMA/MA volume ratio, initiator and fiber mass ratio on the mechanical properties of the composites were investigated. Results showed that the flexural strength of the composites reaches the optimum value when the volume ratio of methyl methacrylate /methyl acrylate (MMA/MA) = 9/1. With the increase of benzoyl peroxide (BPO) mass ratio, the flexural strength of ZrO2(f)/PMMA-PMA composites increases to maximum and then decreases. With the increase of ZrO2 fiber mass ratio, the microstructure of the fractured surfaces changes from smooth to crapy, implying that the toughness of the composites is improved.

scholarly journals PEG-POSS Star Molecules Blended in Polyurethane with Flexible Hard Segments: Morphology and Dynamics

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 99
Author(s):  
Konstantinos N. Raftopoulos ◽  
Edyta Hebda ◽  
Anna Grzybowska ◽  
Panagiotis A. Klonos ◽  
Apostolos Kyritsis ◽  
...  
Keyword(s):  
Glass Transition ◽  
Star Polymer ◽  
Polymerization Process ◽  
Degree Of Crystallinity ◽  
Dielectric Relaxation Spectroscopy ◽  
Scanning Calorimetry ◽  
Similar System ◽  
Soft Phase ◽  
Hard Segments ◽  
Star Molecules

A star polymer with a polyhedral oligomeric silsesquioxanne (POSS) core and poly(ethylene glycol) (PEG) vertex groups is incorporated in a polyurethane with flexible hard segments in-situ during the polymerization process. The blends are studied in terms of morphology, molecular dynamics, and charge mobility. The methods utilized for this purpose are scanning electron and atomic force microscopies (SEM, AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and to a larger extent dielectric relaxation spectroscopy (DRS). It is found that POSS reduces the degree of crystallinity of the hard segments. Contrary to what was observed in a similar system with POSS pendent along the main chain, soft phase calorimetric glass transition temperature drops as a result of plasticization, and homogenization of the soft phase by the star molecules. The dynamic glass transition though, remains practically unaffected, and a hypothesis is formed to resolve the discrepancy, based on the assumption of different thermal and dielectric responses of slow and fast modes of the system. A relaxation α′, slower than the bulky segmental α and common in polyurethanes, appears here too. A detailed analysis of dielectric spectra provides some evidence that this relaxation has cooperative character. An additional relaxation g, which is not commonly observed, accompanies the Maxwell Wagner Sillars interfacial polarization process, and has dynamics similar to it. POSS is found to introduce conductivity and possibly alter its mechanism. The study points out that different architectures of incorporation of POSS in polyurethane affect its physical properties by different mechanisms.

scholarly journals Synthesis of poly (n-butyl acrylate) with tempo by nitroxide mediated polymerization method

2021 ◽  
pp. 096739112110245
Author(s):  
Amrita Sharma ◽  
PP Pande
Keyword(s):  
Butyl Acrylate ◽  
Low Cost ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
High Concentration ◽  
Acrylate Monomer ◽  
Controlled Polymerization ◽  
Acrylate Monomers ◽  
Nitroxide Mediated Polymerization ◽  
Polymerization Method

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

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