scholarly journals Emulsifier-Free Acrylate-Based Emulsion Prepared by Reverse Iodine Transfer Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 730
Author(s):  
Tao Huang ◽  
Qing-Xia Yuan ◽  
Shu-Ling Gong
Keyword(s):  
Molecular Weight ◽  
Emulsion Polymerization ◽  
Water Resistance ◽  
Solid Content ◽  
Chain Extension ◽  
Mass Ratio ◽  
Melamine Formaldehyde ◽  
One Pot ◽  
Moderate Amount ◽  
Iodine Transfer

The self-emulsifying acrylate-based emulsions with solid content 45 wt.% were prepared in 3.5 h by reverse iodine transfer polymerization (RITP), and the polymer molecular weight (Mn) could be 30,000 g·mol−1. The influences of methacrylic acid (MAA) amount, soft/hard monomer mass ratio, and iodine amount on polymerization and latex were investigated. A moderate amount of ionized MAA was needed to stabilize the emulsion. Glass transition temperature (Tg) was decreased with the increasing mass ratio of soft/hard monomer. A higher iodine amount resulted in lower Mn. The increased Mn after chain extension of the polymer with water-insoluble monomers in iterative one-pot method proved the living of polymer. Compared with conventional emulsion polymerization, molecular weight (Mn) could be controlled, and Mn of polymer synthesized in RITP emulsion polymerization is higher; emulsion of polyacrylate-containing hydroxyl monomer units prepared by RITP emulsifier-free radical polymerization is more stable. Good properties, such as hardness, water resistance, adhesion, and increased value of maximum tensile of films modified by reaction of polyacrylate with melamine–formaldehyde (MF) resin, indicated potential application in baking coating.

Water-Resistance Material from Fibers and Acrylic Emulsion Terpolymer

2015 ◽  
Vol 1083 ◽  
pp. 40-45
Author(s):  
Hai Peng Wu
Keyword(s):  
Water Resistance ◽  
Fiber Material ◽  
Short Fiber ◽  
Solid Content ◽  
Mass Ratio ◽  
Resistant Material ◽  
Acrylic Emulsion ◽  
Feeding Modes ◽  
Lower Variation ◽  
Scanning Electron

Styrene (SM), methyl methacrylate (MMA), and butyl acrylate (BA) were used to synthesize a polyacrylic emulsion by core-shell emulsion polymerization. The solid content of the emulsion reached 40% using reasonable reactive emulsifier contents and feeding modes. Then, two kinds of fibers (recovered and hardwood fiber) were respectively dispersed, coated, and dried with emulsion. Finally, fiber-based water-resistant material was successfully fabricated. The experimental results showed that under the conditions of a mass ratio of polyacrylic emulsion to fiber of 2:1, the Cobb value of the material reached 7.1 g/m2 and 10.8 g/m2 respectively. Cobb value of recovered fiber material was more stable than hardwood fiber, and stayed in a lower variation scope on the whole. Using scanning electron microscopy (SEM) to observe the surface morphology of products. The SEM results proved that, the polyacrylic emulsion filled the gaps between fibers, decreased the porous structure. This filling effect led to a continuous structure, and kept the water from infiltrating inside of the material. On the other hand, for the short fiber in recovered fiber material arranged closer, the water resistance of the material was further enhanced.

scholarly journals Soybean Meal-Based Wood Adhesive Enhanced by Phenol Hydroxymethylated Tannin Oligomer for Exterior Use

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 758
Author(s):  
Mingsong Chen ◽  
Yi Zhang ◽  
Yue Li ◽  
Sheldon Q. Shi ◽  
Jianzhang Li ◽  
...  
Keyword(s):  
Soybean Meal ◽  
Water Resistance ◽  
Moisture Absorption ◽  
Formaldehyde Emission ◽  
Wood Adhesive ◽  
Solid Wood ◽  
Solid Content ◽  
Mass Ratio ◽  
Residual Rate ◽  
Synthetic Adhesives

Bio-based adhesives have low water resistance and they are less durable than synthetic adhesives, which limits their exterior applications. In this study, a bio adhesive was developed from soybean meal and larch tannin that was designed for exterior use. Phenol hydroxymethylated tannin oligomer (PHTO) was synthesized and then mixed with soybean meal flour in order to obtain a soybean meal-based adhesive (SPA). The results showed that the moisture absorption rate, residual rate, and solid content of SPA with 10 wt % PHTO (mass ratio with respect to the entire adhesive) were improved by 22.8%, 11.6%, and 6.8%, respectively, as compared with that of pure SPA. The wet shear strength of plywood with SPA with 10 wt % PHTO (boiling in 100 °C water for 3 h) was 1.04 MPa when compared with 0 MPa of pure SPA. This met the bond strength requirement of exterior-use plywood (GB/T 9846.3-2004). This improved adhesive performance was mainly due to the formation of a crosslinked structure between the PHTO and the protein and also PHTO self-crosslinking. The formaldehyde emission of the resulting plywood was the same as that of solid wood. The PHTO-modified SPA can potentially extend the applications of SPAs from interior to exterior plywood.

scholarly journals Preparation of Emulsifier-Free Styrene–Acrylic Emulsion via Reverse Iodine Transfer Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3348
Author(s):  
Tao Huang ◽  
Shuling Gong
Keyword(s):  
Mechanical Properties ◽  
Random Copolymer ◽  
Solid Content ◽  
Polymer Materials ◽  
Chain Extension ◽  
Functional Monomer ◽  
Adhesive Properties ◽  
Acrylic Emulsion ◽  
Iodine Transfer ◽  
Reference Amount

Styrene–acrylic emulsions containing hydroxyl functional monomer unit’s component are widely used for maintenance coating. In this paper, a stable emulsifier-free styrene–acrylic emulsion with solid content over 43% could be obtained in 210 min via reverse iodine transfer polymerization (RITP). By adding a mixture of methacrylic acid (MAA) and poly(ethylene glycol)methyl ether methacrylate (PEGMA) into a system containing a high content of hydroxyl functional monomer component (19.4 wt.% of the total monomer mass), styrene (St) could be copolymerized with methyl methacrylate (MMA); the modified film exhibited good hardness properties, good adhesive properties, and low water absorption. An increase in the amount of PEGMA decreased the glass transition temperature (Tg). When 1.4 times the reference amount of initiator was added, the highest molecular weight Mn could reach 40,000 g.·mol−1 with 0.25 times the reference amount of iodine in the emulsion. The largest tensile strength of the dried emulsion film over 5.5 MPa endowed the material with good mechanical properties. Living polymerization was proven by the kinetics of RITP emulsion and chain extension reaction. TEM micrographs manifest the emulsification of the seed random copolymer. This paper may provide a potential methodology for preparing polymer materials with excellent mechanical properties.

The Synthesized of Nano-SiO2 and Silicon Modified Polyacrylate Emulsion

2014 ◽  
Vol 496-500 ◽  
pp. 242-245 ◽  
Author(s):  
Fa Qiu Hou ◽  
Yan Zhao ◽  
Ning Qing ◽  
Yong Jun Chen
Keyword(s):  
Emulsion Polymerization ◽  
Silane Coupling Agent ◽  
Water Resistance ◽  
Sol Gel ◽  
Solid Content ◽  
Raw Material ◽  
Silane Coupling ◽  
Gel Technique ◽  
The Stability ◽  
Stability Of Emulsion

50% solid content of nano-SiO2/silicon modified polyacrylate composite emulsion was synthesized by emulsion polymerization and sol-gel technique with MMA, BA, silane coupling agent (KH-570) and tetraethoxysilane (TEOS) as the main raw material. The influence of some parameters on the properties of emulsion and film were studied, such as initiator, emulsifier, 3-methacryloxypropyltrimethoxysilane(KH-570), tetraethoxysilane(TEOS). The results showed that as the dosage of tetraethoxysilane (TEOS) and organic silicon(KH-570) increased, the stability of emulsion polymerization decreased; The emulsion with good polymerization stability and film with good water resistance were obtained when the mass of initiator is 0.5%, the mass of compound emulsifier is 4%, of which the ratio of OP-10/SDBS/DNS-86=5:3:2, the mass of KH-570 is 2% and the mass of TEOS is 1%.

Preparation and characterization of AKD sizing agent by “one-pot cooking”

2018 ◽  
Vol 33 (2) ◽  
pp. 317-326 ◽  
Author(s):  
Lian Qing Huang ◽  
Xiao Ming Song ◽  
Lu Qing Cui ◽  
Shan Shan Gao ◽  
Fu Shan Chen ◽  
...  
Keyword(s):  
Water Resistance ◽  
Preparation Method ◽  
Solid Content ◽  
Optimum Conditions ◽  
Reaction Parameters ◽  
Starch Solution ◽  
One Pot ◽  
Solids Content ◽  
Temperature Time

Abstract Alkyl ketone dimer (AKD) is a reactive sizing agent commonly used in neutral or alkaline papermaking. Most traditional methods consist in preparing the AKD emulsion and then adding it to a starch solution. In this study, the preparation process of the AKD sizing liquid was improved and optimized. A novel preparation method of the AKD sizing agent was proposed. The effects of different reaction parameters, such as temperature, time, stirring speed, emulsifier dosage and solid content were investigated. The optimum conditions for preparing the AKD sizing agent were determined, and the sizing liquid was characterized. It was found that the water resistance of the coated paper was the highest when the reaction was carried out at 75 °C for 20 min, at a stirring speed of 700 r/min, with the emulsifier dosage of 9 % and solids content of 15 %.

scholarly journals Synthesis and Thermal Degradation Studies of Melamine Formaldehyde Resins

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sami Ullah ◽  
M. A. Bustam ◽  
M. Nadeem ◽  
M. Y. Naz ◽  
W. L. Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Monomer Concentration ◽  
Solid Content ◽  
Molecular Weight Determination ◽  
Melamine Formaldehyde ◽  
Molar Ratios ◽  
Ph Values ◽  
Residual Weight

Melamine formaldehyde (MF) resins have been synthesized at different reaction temperature and pH values. Different molar ratios of melamine and formaldehyde were used to synthesize the corresponding resins. The prepared resin samples were characterized by using molecular weight determination viscometry and thermogravimetric analysis (TGA). The maximum percentage of solid content (69.7%) was obtained at pH 8.5 and 75°C temperature. The molecular weight of MF resin was increased with an increase of melamine monomer concentration. The highest residual weight 14.125 wt.% was obtained with sample 10.

scholarly journals Poly(lactic Acid): A Versatile Biobased Polymer for the Future with Multifunctional Properties—From Monomer Synthesis, Polymerization Techniques and Molecular Weight Increase to PLA Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Practical Applications ◽  
Decomposition Reactions ◽  
Melt Polycondensation ◽  
Polymerization Conditions ◽  
Molecular Weight Increase

Environmental problems, such as global warming and plastic pollution have forced researchers to investigate alternatives for conventional plastics. Poly(lactic acid) (PLA), one of the well-known eco-friendly biodegradables and biobased polyesters, has been studied extensively and is considered to be a promising substitute to petroleum-based polymers. This review gives an inclusive overview of the current research of lactic acid and lactide dimer techniques along with the production of PLA from its monomers. Melt polycondensation as well as ring opening polymerization techniques are discussed, and the effect of various catalysts and polymerization conditions is thoroughly presented. Reaction mechanisms are also reviewed. However, due to the competitive decomposition reactions, in the most cases low or medium molecular weight (MW) of PLA, not exceeding 20,000–50,000 g/mol, are prepared. For this reason, additional procedures such as solid state polycondensation (SSP) and chain extension (CE) reaching MW ranging from 80,000 up to 250,000 g/mol are extensively investigated here. Lastly, numerous practical applications of PLA in various fields of industry, technical challenges and limitations of PLA use as well as its future perspectives are also reported in this review.

scholarly journals Chitosan-Based Adhesive: Optimization of Tensile Shear Strength in Dry and Wet Conditions

2021 ◽  
Vol 2 (1) ◽  
pp. 110-120
Author(s):  
Maisa Abdelmoula ◽  
Hajer Ben Hlima ◽  
Frédéric Michalet ◽  
Gérard Bourduche ◽  
Jean-Yves Chavant ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Strength ◽  
Bond Strength ◽  
Water Resistance ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Spread Rate ◽  
Assembly Time ◽  
Deacetylation Degree ◽  
Dry And Wet Conditions

Commercial adhesives present a high bond strength and water resistance, but they are considered non-healthier products. Chitosan can be considered as an interesting biosourced and biodegradable alternative, despite its low water resistance. Here, its wood bonding implementation and its tensile shear strength in dry and wet conditions were investigated depending on its structural characteristics. Firstly, the spread rate, open assembly time, drying pressure, drying temperature, and drying time have been determined for two chitosans of European pine double lap specimens. An adhesive solution spread rate of 1000 g·m−2, an open assembly time of 10 min, and a pressure temperature of 55 °C for 105 min led to a bond strength of 2.82 MPa. Secondly, a comparison between a high molecular weight/low deacetylation degree chitosan and a lower molecular weight/higher deacetylation degree chitosan was conducted. Tests were conducted with beech simple lap specimens in accordance with the implementation conditions and the conditioning treatments in wet and dry environments required for thermoplastic wood adhesive standards used in non-structural applications (EN 204 and EN 205). The results clearly revealed the dependence of adhesive properties and water resistance on the structural features of chitosans (molecular weight and deacetylation degree), explaining the heterogeneity of results published notably in this field.

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