The Influence of Surfactant and Protective Colloid on Polyvinyl Acetate Emulsion Synthesized by Emulsion Polymerization Technique (original) (raw)
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Synthesis and characterization of emulsion polymers using isopropenyl acetate
International Journal of Industrial Chemistry, 2012
Background: Isopropenyl acetate (IPA) is one of the monomers from acetate family having an unsaturation with a methyl group attached to the ethylenic carbon. The unsaturation present in the monomer can be utilized for free radical polymerization. Irrespective of this, IPA is not studied much in emulsion polymer synthesis. In the current study, we report the preparation of emulsion polymers using IPA and other acrylic monomers. Terpolymers of butyl acrylate (BA), methyl methacrylate, and IPA were prepared via seeded emulsion polymerization with varying IPA proportions on molar basis. Potassium persulfate was employed as an initiator along with Dowfax 2A1 as surfactant (anionic). Results: The emulsions prepared thereof were characterized for particle size, zeta potential and molecular weight using gel permeation chromatography. The emulsion films were evaluated using Fourier transform infrared spectroscopy, as well as their thermal (differential scanning calorimetry, thermo gravimetric analysis) and mechanical properties to study the effect of isopropenyl acetate on their overall properties. Conclusions: With increasing proportion of IPA in the formulation, lower conversion was observed which could be due to the lower reactivity of IPA for radical polymerization in the presence of these comonomers. More study for the utilization of IPA in polymer synthesis is needed which, on successful optimization, would give a cost-effective alternative to various commercial acrylic monomers.
Iranian Polymer Journal, 2007
P oly(vinyl alcohol) (PVA) is a water soluble polymer with excellent physical and chemical properties. The basic properties of this polymer depend on its molecular weight, degree of hydrolysis and distribution. Since the commercial applications of PVA are many and varied, therefore, a special grade of PVA with considerable properties is required as an emulsifier. A polymerized ester can be used for preparation of PVA types, because vinylalcohol monomer does not exist in the free state. The characteristics of the preparation of poly(vinyl acetate) (PVAc) are very important in the manufacture of PVA. In this work, a partially hydrolyzed grade of PVA having characteristics suitable for application in emulsion polymerization of vinyl acetate (VAc) (M v : 77200, hydrolysis degree: 89.2%) was prepared by investigation of reaction conditions for solution polymerization of VAc by the aids of α,α' azobisisobutyronitrile (AIBN) initiator in methanol and the subsequent saponification reaction of the resulted PVAc in the presence of NaOH. This was including investigation of the effect of [VAc]/[AIBN] ratio and polymerization time for preparation of PVAc at 60ºC in terms of VAc conversion and PVAc molecular weight, then the effect of saponification time of PVAc in terms of the molecular weight and hydrolysis degree of PVA product. In case of some samples, concentration of the monomer relative to that of the initiator plays an important role in VAc conversion value and controlling the PVAc molecular weight. The results from saponification of PVAc samples revealed that, only one of the samples was that its saponification resulted in PVA material desired molecular weight at 1 h. 1 H NMR Spectra of PVAc and PVA were used to show a branched molecular structure of PVAc and estimation of the degree of hydrolysis of a PVA sample. The presence of typical characteristics absorption bands in IR spectra of PVAc and PVA samples agrees with proposed structures. To confirm the result earned, the characteristics of PVA obtained were compared with those of the commercially used PVA grades (Mowiols).
Emulsion Polymerization of Styrene and Vinyl Acetate with Cationic Surfactant
Macromolecular Symposia, 2007
In this study, the emulsion homopolymerization system containing vinyl acetate and styrene, potassium persulfate, and a new cationic surfactant was studied in the classical glass emulsion polymerization reactor. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate and styrene latex properties were investigated depending on surfactant percentage in homopolymerizations.
Miniemulsion polymerization of vinyl acetate with nonionic surfactant
Journal of Applied Polymer Science, 1994
SYNOPSIS The stability of vinyl acetate miniemulsions employing polyvinyl alcohol (PVOH) as the surfactant, and hexadecane and/or various polymers as the cosurfactant, were studied. Shelf lives (to phase separation) and monomer droplet sizes were measured. The results indicate that it is possible to prepare stable miniemulsions using a nonionic surfactant (PVOH) and hexadecane as the cosurfactant. Polymeric cosurfactants do not create stable miniemulsions but retard Ostwald ripening to an extent that allows predominant droplet nucleation. The polymerization behavior of these miniemulsion systems was investigated using on-line conductance measurements to differentiate droplet versus micellar/homogeneous nucleation. The effect of cosurfactant concentration on the reaction rate was compared for hexadecane and polymeric cosurfactants. 0 1994 John Wiley & Sons, Inc.
Cellulose Stabilized Polyvinyl Acetate Emulsion: Review
2021
The global energy crisis and overconsumption of non-renewable resources have depleted natural resources, climatic changes with global warming, and rise in sea level. The research on alternate sources and chemicals has resulted in the usage of green materials. These biomaterials are sustainable sources, biodegradable, and are abundant in nature. The replacement of petrochemicals with biopolymers has gained much importance in this aspect. Conventionally, polyvinyl alcohol is employed as a protective colloid in polyvinyl acetate adhesive. Polyvinyl alcohol has the limitation of petroleum origin, is replaced by biopolymers. Starch being a biopolymer, has gained interest in replacing polyvinyl alcohol as a stabilizer. Cellulose has a low cost, and the most abundant biomaterial finds application as a reinforcing agent in conventional adhesives. Exploring cellulose as a stabilizer for polyvinyl acetate emulsion polymerization with reinforcement has created potential applicability of cellul...
Waterborne nano-emulsions of polyvinyl acetate-polyurethane coatings containing different types of vinyl monomers: synthesis and characterization, 2021
Purpose-This paper aims to synthesize new terpolymers by the emulsion polymerization technique composed of acrylamide-based polyurethane monomers (TPM and MPM) with different vinyl acetate copolymer systems, such as vinyl acetate/butyl acrylate (VAc/BA), vinyl acetate/ethylhexyl acrylate (VAc/2-EHA) and vinyl acetate/vinyl ester of versatic acid (VAc/VEOVA 10) systems. The performance of the prepared terpolymers as binders in emulsion coatings and textile industries was investigated and compared with the analogous commercial ones. Design/methodology/approach-New waterborne polyurethane-vinyl ester-vinyl acetate terpolymers with high solid content and nano-scale emulsions have been successfully synthesized in two steps. The polyurethane oligomers were prepared by the prepolymer method as the first step. The second step involved polymerization with different vinyl monomers. The synthesized terpolymers were characterized using FTIR, scanning electron microscope, thermogravimetric analysis, minimum film forming temperature and particle size analyzer methods. Findings-The synthesized emulsion terpolymers have shown small particle sizes averaged of 70 nm and a narrow distribution range, along with good mechanical, thermal and chemical stabilities. The surface coating layers of the terpolymers also have some important in terms of smoothness, clarity and binding ability in water-based coating for up to 4425 scrub cycles at 30 GU. Further, a high potential application textile printing was achieved at high solid content of 47-50%. Originality/value-The effects of different isocyanates and vinyl monomers on the properties of obtained emulsion coatings have been studied. The improvement consequences of the coating evaluation of the waterborne binders for emulsion paints have been described. The properties of polyester/cotton fabric print pigment printing of textiles appear to be most promising enhancements by using the prepared nanocomposites of PUco-vinyl acetate-co-vinyl ester as waterborne binders. So that the prepared emulsions have the potential to replace solvent-based coatings as waterborne binders for both emulsion coating and textile printing applications.
Indian Journal of Clinical Biochemistry, 2013
Emulsion polymerization was used to synthesize poly butyl cyanoacrylate nanoparticles in presence of steric stabilizer dextran 70. Nanoparticles were characterized by particle size analysis, scanning electron microscopy and light microscopy. Polymerization factors affecting particle size and distribution such as dextran 70, polysorbate 80 (PS 80) and H ? concentration, polymerization time and temperature, and sonication were studied. Distinct concentrations of stabilizer were needed to produce proper nanoparticles. In this case, the appropriate value was 2 % of total volume. At pH 4 significant decrease in production efficiency demonstrated the substantial effect of H ? concentration on nanoparticles. Furthermore significant increases in particle size and distribution was observed at 50°C compared to room temperature. 0.001 % (v/v) PS 80 represented notable influence on size and distribution. In addition, shaped nanoparticles were obtained by altering polymerization time from 5.5 h to 18 h. Finally, nanoparticle features were influenced by different factors. Appropriate manipulating of such factors can lead to obtaining desirable nanoparticles.
Polymers for Advanced Technologies, 2009
Two types of emulsifier were studied to compare the colloidal and physicochemical properties of vinyl acetate (VAc)/ (BuA) emulsions. Emulsions were prepared by varying the composition and the concentration of the anionic and nonionic emulsifiers. An increase in the total emulsifier concentration of anionic and nonionic emulsifier percentage leads to dispersions with smaller particles and higher viscosities. Using anionic and nonionic emulsifiers in copolymer latexes, it was observed that the viscosity goes through a maximum which is located at total emulsifier concentration of about 3.6 wt% The surface tension of the copolymers shows a drastic increase at a concentration above 3.5% for mixed emulsifier systems.
Polymer Bulletin, 2011
Monomer mixtures of vinyl acetate (VAc)/butyl acrylate (BuA) were polymerized in batch reactions at 60°C with potassium persulfate as the initiator in microemulsions consisting of VAc:BuA (85:15 wt/wt)/water/sodium dodecyl sulfate (SDS)/polyoxyethylene (23) dodecyl ether (3:1 wt/wt). The effect of the concentration of the monomer mixture on the kinetics was studied. It was found that, as the total monomers concentration ([M] 0) increases, the polymerization rate increases also, and that the maximum polymerization rate is proportional to [M] 0 1.26. Particle size increases with total monomers concentration. In all cases, final average particle diameter was less than 50 nm. Particle number density is independent of total monomers concentration. A mathematical model that takes into account the partition of monomers between the different phases during polymerization using a minimum of adjustable parameters was applied to simulate the experimental data. A correlation for the radical desorption coefficient, which is a function of the rate of
Kinetics of miniemulsion polymerization of vinyl acetate with nonionic and anionic surfactants
Journal of Applied Polymer Science, 2001
The kinetics of miniemulsion polymerization of vinyl acetate, in which nonionic surfactant, Brij-35 [polyoxyethylene(23) lauryl ether], and hexadecane were used, was investigated. For comparison, experiments were also carried out using an anionic surfactant (sodium lauryl sulfate). The results show that, for all experiments, both distributions for the particle size of the latices and the molecular weight of polymers were unimodal. The effects of surfactant and initiator levels on the particle number and the polymerization rate were studied. For the system using Brij-35, the power orders for the dependence of particle number on surfactant and initiator concentrations were 1.33 and 0.68, respectively. The polymerization rate was proportional to the 0.38 power of surfactant level and the 0.84 power of initiator concentration. The hydration layer outside the monomer-swollen particles in the system of nonionic surfactant may exert a retardation effect on the entry of oligomeric radicals into the particles. The result of GPC analysis indicates that the surfactant concentration inversely affects the molecular weight.