Preparation and Properties of Thermally Expandable Microspheres for Foam Coating

2021 ◽  
Vol 116 (7) ◽  
Author(s):  
Guodong Huang ◽  
Zhixian Lin ◽  
Haojun Fan ◽  
Jun Xiang ◽  
Chong Zheng ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Suspension Polymerization ◽  
Crosslinking Agent ◽  
Diameter Ratio ◽  
Mass Ratio ◽  
Solvent Resistance ◽  
Crosslinking Degree ◽  
Foaming Agent ◽  
Application Requirements ◽  
Expansion Temperature

A type of thermally expandable microspheres (TEMs) for foam coating was prepared by suspension polymerization with acrylonitrile (AN), methyl methacrylate (MMA), vinyl acetate (VAC) as shell polymer monomers and i-pentane as core foaming agent. The effects of an aqueous additive (Sodium Chloride, NaCl) on the size and distribution of TEMs, and the effects of crosslinking degree, i-pentane dosage and monomer mass ratio on the expansion property, expansion temperature and solvent-resistance of TEMs were investigated. The results showed that when the dosage of NaCl was close to the saturation solubility (30%), the dosage of crosslinking agent and alkane were about 0.09% and 7.4%, and the mass ratio of AN/MMA/VAC w rm distribution and good solvent resistance, the expansion diameter ratio was 5 times under 110~120 C, which meets the application requirements for foam coating of leather or synthetic leather.

Synthesis of high-temperature thermally expandable microcapsules and their effects on foaming quality and surface quality of foamed ABS materials

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 519-527
Author(s):  
Wei Gong ◽  
Xianglin Pei ◽  
Xiaogang Yin ◽  
Daming Ban ◽  
Hai Fu ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Quality ◽  
Volume Fraction ◽  
Crosslinking Agent ◽  
Acrylonitrile Butadiene Styrene ◽  
Foaming Agent ◽  
Blowing Agent ◽  
Good Surface ◽  
Butadiene Styrene

AbstractIn this paper, acrylonitrile and hydroxypropyl acrylate are used as the binary polymerization monomers, and isooctane is used as the foaming agent to prepare high-temperature thermally expandable microcapsules. Analysis of the effect of blowing agent and crosslinking agent on the expansion properties of high-temperature thermally expandable microcapsules, the effects of foaming agent azodicarbonamide (ADCA) and micro-expansion capsule on the surface quality and foaming quality of foamed acrylonitrile–butadiene–styrene (ABS) products were investigated. The foamed product prepared by the high-temperature microcapsule has a good surface quality, the gloss is 52.3, the cell is not easily deformed, and the volume fraction is 4%; the foamed ABS/ADCA material has poor cell uniformity, the cell is easily deformed, the volume fraction is 6.5%, the surface quality is poor, and the gloss is only 8.7.

Studies of Mechanical Properties and Melting Behaviour of Foamed and Crosslinked LDPE/PP Blends

2002 ◽  
Vol 21 (6) ◽  
pp. 431-443 ◽  
Author(s):  
George Kotzev
Keyword(s):  
Mechanical Properties ◽  
Melting Behaviour ◽  
Crosslinking Degree ◽  
Foaming Agent ◽  
Pp Blends ◽  
Insoluble Portion

Foamed crosslinked specimens of LDPE/PP blends produced by RIM process were examined. A crosslinking system containing 2,5-dimethyl-2,5-di(tert.-butylperoxy)hexane as an initiator and hydroquinone as a coagent was used. Azodicarbonamide was applied as a foaming agent. The crosslinking degree was evaluated by insoluble portion of the blends. An improvement of the mechanical properties due to crosslinking mainly in the LDPE phase as well as crosslinking between polyethylene and polypropylene on their interface was observed. Melting behaviour of the blends studied by DSC shows that both the initiator and the coagent cause opposite effects on temperatures and enthalpies of melting.

Studies on Multihollow PUA-EMA-St Crosslinked Copolymer Beads: Synthesis and Hollow Structure

2011 ◽  
Vol 295-297 ◽  
pp. 60-63
Author(s):  
Wei Hong Sun ◽  
Xin Yan
Keyword(s):  
Suspension Polymerization ◽  
Crosslinking Agent ◽  
Hollow Structure ◽  
Copolymer Composition ◽  
Ethyl Methacrylate ◽  
Polyurethane Acrylate

The multihollow and elastomeric beads from polyurethane acrylate (PUA), ethyl methacrylate (EMA) and styrene (St) are prepared by suspension polymerization using n-heptane as porogen and 1,2-divinylbenzene (DVB) as crosslinking agent. The SEM results show that the beads of PUA-EMA-St crosslinked copolymers have many and large hollows on their surfaces and interiors, and the hollow sizes are dependence of the copolymer composition and the dosages of porogen. Average hollow diameters decrease as the dosages of the contents of PUA and porogen decrease.

The Hydrodynamic Forces Acting on a Long Flexible Circular Cylinder Responding to VIV

2006 ◽  
Author(s):  
P. W. Bearman ◽  
F. J. Huera Huarte ◽  
J. R. Chaplin
Keyword(s):  
Circular Cylinder ◽  
Cross Flow ◽  
Element Model ◽  
Transverse Force ◽  
Diameter Ratio ◽  
Mass Ratio ◽  
Force Coefficients ◽  
Fluid Forces ◽  
Maximum Value ◽  
Vibration Prediction

Distributions of the fluid forces acting along a long flexible circular cylinder free to respond in-line and transverse to a stepped current are presented. Forces are calculated using a finite element model of the cylinder with measured responses providing the input. The length to diameter ratio of the model used was 469, the mass ratio was 3 and the Reynolds number could be varied up to maximum value of approximately 2.6 · 104. Fluid force coefficients for two cases are presented: in the first, the dominant modes are the 2nd cross-flow and the 4th in line. For the second case the leading modes are the 7th and 12th respectively. In general, transverse force coefficients and in-line drag coefficients are found to be larger than those measured for short sections of cylinder undergoing free and forced one and two-dimensional motions. It is anticipated that the results will be of value to developers of vortex-induced vibration prediction methods.

Preparation of Poly (MMA-S-DVB) Microspheres by Suspension Polymerization Method

2013 ◽  
Vol 745-746 ◽  
pp. 53-59 ◽  
Author(s):  
Si Qun Chen ◽  
Zi Cai Sun ◽  
Xiao Wei Wang ◽  
Xiao Hui Chen ◽  
Jian Jun Chen
Keyword(s):  
Suspension Polymerization ◽  
Absorption Analysis ◽  
Mass Ratio ◽  
Macroporous Resin ◽  
Reaction Conditions ◽  
Divinyl Benzene ◽  
Optimum Reaction ◽  
Ft Ir ◽  
Oil Water ◽  
Polymerization Method

In this work, Poly (methy methacrylate-styrene-divinyl benzene) (MMA-S-DVB) microspheres were prepared by suspension polymerization approach in the presence of n-dodecane as porogenic agent. Various types of measurements,such as binocular biological microscope with micrometer, fourier transform infrared (FT-IR) and N2 absorption analysis (BET) were conducted to characterize the MMA-S-DVB microspheres. The effect of the amount of surfactants (PVA and NaCl), porogenic agent and crossing agent (DVB) on the morphology of microspheres was investigated and mass ratio of oil/water and the stirring speed were also discussed. Finally, according to the experimental results,the optimum experimental condition was obtained as follow: the mass ratio of S:MMA:DVB=3:3:4, the concentration of PVA in the water phase is 2.2 wt %, the concentration of NaCl is 5 wt %, the mass ratio of oil/water is 1:11, the stirring speed is 500rpm.Via controlling the optimum reaction conditions of the suspension polymerization, the crosslinked macroporous resin polymer MMA-S-DVB microspheres with excellent sphericity and controllable diameter in a range of 200~400 μm can be gained.

Study on Solvent Resistance of Ternary Plastic Alloys of PEEK/PEI/PES

2014 ◽  
Vol 900 ◽  
pp. 27-31
Author(s):  
Jian Bing Chen
Keyword(s):  
Dimethyl Formamide ◽  
Twin Screw Extruder ◽  
Mass Ratio ◽  
Screw Extruder ◽  
Solvent Resistance ◽  
Mass Ratios ◽  
Twin Screw

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C separately with five mass ratios of 70/30/0, 70/25/5, 65/30/5, 60/30/10, The solvent resistance were investigated by experiments, their results showed that the concentrated H2SO4 resistance of alloy plates had been improved by alloying in 6h, the acetone resistance of mass ratio of 70/25/5 is preferably, increasing the content of PES, the acetone resistance becomes relatively stable, in addition, the chloroform and N, N-dimethyl formamide resistance of mass ratio of 70/25/5 is also preferably, and the polarity of the reagent has a limit influence on solvent resistance of plastics alloy materials.

Preparation of Polystyrene Microspheres by Suspension Polymerization

2011 ◽  
Vol 233-235 ◽  
pp. 2215-2218 ◽  
Author(s):  
Jin Ling Ma ◽  
Xing Hua Zhang
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Suspension Polymerization ◽  
Mass Ratio ◽  
Initiator Concentration ◽  
Polystyrene Microspheres ◽  
Average Size

Polystyrene (PS) microspheres with different sizes were prepared by suspension polymerization. The effect of initiator concentration on the average sizes and size distribution was evaluated. The results showed that the average size of PS microspheres increases with increasing initiator content, the optimal uniformity of PS microspheres was attained when the mass ratio of BPO to styrene was 1.5:100. The effect of stirring speed on the particle size was also investigated. The average size of PS microspheres reduced with the increase of the stirring speed.

scholarly journals Radiation Graft-Copolymerization of Ultrafine Fully Vulcanized Powdered Natural Rubber: Effects of Styrene and Acrylonitrile Contents on Thermal Stability

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3447
Author(s):  
Niratchaporn Rimdusit ◽  
Chanchira Jubsilp ◽  
Phattarin Mora ◽  
Kasinee Hemvichian ◽  
Tran Thi Thuy ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Natural Rubber ◽  
Graft Copolymers ◽  
Crosslinking Agent ◽  
Solvent Resistance ◽  
Emulsion Copolymerization ◽  
Monomer Content ◽  
Average Size ◽  
Sem Morphology ◽  
Deproteinized Natural Rubber

Graft copolymers, deproteinized natural rubber-graft-polystyrene (DPNR-g-PS) and deproteinized natural rubber-graft-polyacrylonitrile (DPNR-g-PAN), were prepared by the grafting of styrene (St) or acrylonitrile (AN) monomers onto DPNR latex via emulsion copolymerization. Then, ultrafine fully vulcanized powdered natural rubbers (UFPNRs) were produced by electron beam irradiation of the graft copolymers in the presence of di-trimethylolpropane tetra-acrylate (DTMPTA) as a crosslinking agent and, subsequently, a fast spray drying process. The effects of St or AN monomer contents and the radiation doses on the chemical structure, thermal stability, and physical properties of the graft copolymers and UFPNRs were investigated. The results showed that solvent resistance and grafting efficiency of DPNR-g-PS and DPNR-g-PAN were enhanced with increasing monomer content. SEM morphology of the UFPNRs showed separated and much less agglomerated particles with an average size about 6 μm. Therefore, it is possible that the developed UFPNRs grafted copolymers with good solvent resistance and rather high thermal stability can be used easily as toughening modifiers for polymers and their composites.

Development of a Novel In-Situ-Generated Foamed Gel as Temporary Plugging Agent Used for Well Workover: Affecting Factors and Working Performance

SPE Journal ◽  
2019 ◽  
Vol 24 (04) ◽  
pp. 1757-1776 ◽  
Author(s):  
Hu Jia ◽  
Xin-Yu Yang ◽  
Jin-Zhou Zhao
Keyword(s):  
High Speed ◽  
Gas Permeability ◽  
Crosslinking Agent ◽  
Low Pressure ◽  
Fluid Loss ◽  
Coefficient Function ◽  
Foaming Agent ◽  
Working Performance ◽  
The Stability

Summary Foams can be used as well-killing fluid for workover operation in low-pressure oil and/or gas wells. However, foams usually come from gas injection under high pressure or high-speed stirring, which is complicated, expensive, and hazardous. In addition, the foam's stability is still limited by the current method of adding viscous polymer or the single crosslinking between the polymer and single crosslinking agent. This paper explores a simple and safe in-situ generating procedure under surface conditions by virtue of the coefficient function of the CO2-gas-producing chemicals (GPCs) and the foaming agent. The foam stability is enhanced through the double crosslinking with the application of chromium acetate III (Cr3+) and polyethyleneimine (PEI), which guarantees its stability in the wellbore. This systematic study consists of optimization of different foaming agents, gel bases, and the effect of the GPC compositions (carbonate and acid) and their quantity, a macroscopic comparison of the stability and rheological properties of the double crosslinking and the common single crosslinking systems, with further investigation of their stability differences through microscopic research, and a coreflooding experiment to evaluate working performance. Within 4 days, the density of this novel foamed gel varies from 0.711 to 0.910 g/cm3 at 35°C, satisfying the present operation requirements for density and stability. This is because of the function of the GPCs and foaming agent, which means that finer foams can be obtained to achieve target low density. Meanwhile, on the basis of the double crosslinking, a more compact gel structure is formed; thus the stability can be effectively improved. Results also demonstrated that this foamed gel shows a favorable performance of low fluid loss and temporary plugging, and the gas-permeability-recovery rate is up to 93.90%, which proves the gel to be effective for formation-damage control. This study suggests that the novel in-situ-generated foamed gel has the potential to achieve favorable well-workover performance in low-pressure and low-temperature reservoirs.

scholarly journals Ingredient of Biomass Packaging Material and Compare Study on Cushion Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Fangyi Li ◽  
Kaikai Guan ◽  
Peng Liu ◽  
Gang Li ◽  
Jianfeng Li
Keyword(s):  
Compressive Strength ◽  
Starch Content ◽  
Active Agent ◽  
Packaging Material ◽  
Hydroxyl Groups ◽  
Packaging Materials ◽  
Mass Ratio ◽  
Foaming Agent ◽  
Plastic Packaging ◽  
The Impact

In order to reduce the white pollution caused by nondegradable waste plastic packaging materials, the biomass cushion packaging material with straw fiber and starch as the main raw materials had been synthesized. The orthogonal experiment was used to study the impact of mass ratio of fiber to starch, content of plasticizer, active agent, and foaming agent on the compressive strength of cushion material. Infrared spectrometer and theory of water’s bridge-connection were used to study the hydroxyl groups among the fiber and starch. The results were demonstrated as follows: the mass ratio of fiber to starch had the most significant impact on compressive strength. When the contents of the plasticizer, the foaming agent, and the active agent were, respectively, 12%, 0.1%, and 0.3% and the mass ratio of fiber to starch was 2 : 5, the compressive strength was the best up to 0.94 MPa. Meanwhile, with the plasticizer content and the mass ratio of fiber to starch increasing, the cushioning coefficient of the material decreased first and then increased. Comparing the cushion and rebound performance of this material with others, the biomass cushion packaging material could be an ideal substitute of plastic packaging materials such as EPS and EPE.

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