浅谈叔碳酸乙烯酯的特性与开发

叔碳酸乙烯酯以其独特的结构,使其具有优异的耐候、耐碱、共聚和环保成膜性。目前叔醋乳液的性能已经接近苯丙、纯丙,叔醋乳胶涂料得到迅猛发展。我国在叔碳酸生产技术上取得极大突破,为叔碳酸乙烯酯的利用和发展提供了坚实基础。目前,研制叔醋乳胶涂料并提高其性价比,或叔碳酸乙烯酯同其他树脂进行共聚以提高其性能和应用范围的研究是重点。     

醋丙乳液型纸塑覆膜胶的研制

以醋酸乙烯(VAc)为硬单体,丙烯酸丁酯(BA)、丙烯酸异辛酯(EHA)为软单体,丙烯酸(AA)、叔碳酸乙烯酯(VV-10)、丙烯酸羟丙酯(HPA)为功能单体,采用乳液聚合方法制备醋丙共聚乳液覆膜胶。讨论了玻璃化温度、功能单体、乳化剂以及引发剂的用量等因素对乳液性能的影响。实验结果表明,当玻璃化温度为23.14℃、w(功能单体)=10%、w(乳化剂)=2%、w(引发剂)=0.4%时,乳液的各项性能良好。     

醋酸乙烯酯—丙烯酸丁酯共聚乳液的合成研究

采用半连续法和间歇法合成了醋酸乙烯酯、丙烯酸丁酯共聚乳液。通过对不同聚合方法合成的乳液胶膜性能的研究,表明半速续法合成的乳液腹膜性能优于间歇法并讨论了其原因。采用半连续法合成不同单体配比的共聚乳液,研究结果表明,胶膜的耐水性、初始粘接强度等性能随丙烯酸丁酯含量的增加而提高。     

The effect of varied monomer composition on adhesive performance and peeling master curves for acrylic pressure‐sensitive adhesives

A group of pressure‐sensitive adhesives were prepared with constant glass transition temperature, using emulsion polymerization. The monomers chosen were butyl acrylate, 2‐ethylhexyl acrylate, and methyl methacrylate, along with a small amount of acrylic acid. The proportion of acrylic acid monomer was held constant for each polymer preparation but acrylic ester monomer levels were varied. The glass transition temperatures of the acrylate copolymers were measured by using differential scanning calorimetry. Drying and weighing the tetrahydrofuran‐insoluble polymer fractions were used to determine the polymer gel fractions. Films of constant coating thickness were applied to poly(ethylene terephthalate) film and adhesive properties (tack and shear) were examined. Peel was examined through the construction of master curves derived from peel tests conducted over a range of temperatures and peel rates. As the 2‐ethylhexyl acrylate content increased, the latex gel fractions were found to increase. With increasing EHA and gel fraction, peel shear was found to increase. When peel force master curves were compared, divergence in peel master curves occurred as peel rates increased where polymers with higher butyl acrylate contents reached greater peel stress values. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2909–2917, 2004     

四元共聚水性防腐涂料乳液的合成与性能研究

用丙烯酸丁酯、苯乙烯、丙烯腈、丙烯酸共聚,得到性能优良的水性防腐涂料乳液;讨论了原料的种类和用量、合成工艺等对乳液性能的影响。     

Colloidal and polymer properties difference of fluorinated acrylate latex prepared with different fluorinated monomers

Fluorinated acrylate latex was prepared by copolymerizing fluorinated monomer, butyl acrylate, and methyl methacrylate, which was initiated by potassium persulfate in the water. The resultant fluorinated latex and its film were characterized with contact angle determinator, dynamic light scattering detector, and differential scanning calorimetry, respectively. Influence of type of fluorinated monomers on colloidal and polymer properties of fluorinated acrylate latex was studied. Results show that the coagulation rate, particle size, contact angle, glass transition temperature, and chemical resistance are increased with the increase of the number of fluorine atom in the fluorinated monomer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

高固含量水基白乳胶的研制

以醋酸乙烯及丙烯酸丁酯为混合单体来制备高固含量水基白乳胶。采用种子乳液聚合法，制备高固含量、中等粘度、稳定性好的聚合物乳液。并探讨了单体配比、第二种子添加量、补加的乳化剂量对制备高固含量、稳定性好的乳液的影响。     

Fluorinated additives for stain-resistant matt latex paints

Latex paints are often preferred over solvent-based paints due to their good gloss and color retention, ease of handling, and lower volatile organic contents. However, matt latex paints tend to show poor stain resistance since they develop highly porous and rough surfaces. In recent years, matt latex paints have been improved in their stain resistance with resulting better cleanability, by adding hydrocarbon acrylic polymers and fluorine-containing compounds. In this work, we prepared fluorinated acrylic emulsions of the copolymer of butyl acrylate (BA) and perfluorobutylethylene (PFBE), which were introduced in latex paint compositions. The properties of the modified paints were evaluated by performing stain resistance tests with several domestic products. It was observed that they had good stain release properties, thus conferring good properties to the final painting system. They contain the self-cleaning behavior typical of fluorinated coatings, which have been proven by the decrease of their surface energies. Since the cleaning procedures of a matt paint film can also impart some gloss increase, the wet and dry burnishes were also evaluated. The results have shown improvements in stain resistance and cleanability of the modified matt latex paints with the maintenance of their stability and the coatings gloss as required.     

Surface structure and properties of water‐based polymer coating materials prepared by the complexation of two polymer latices with chemically complementary structures

In this study, water‐based polymer coating materials used for the surface coating of substrates with lower surface energies were prepared by the complexation of two‐component polymer latices containing polydimethylsiloxane (PDMS) and having chemically complementary structures. The film‐forming performance of the polymer latices and the surface structures and properties of the coatings formed by the polymer latices were studied by means of scanning electron microscopy and by the measurement of mechanical strength, thermal performance, water absorbability, and contact angle. When the two‐component polymer latices [the poly(methyl methacrylate‐co‐butyl acrylate‐co‐methyl acrylic acid)/polydimethylsiloxane system (PA latex) and the poly(methyl methacrylate‐co‐butyl acrylate‐co‐pyrrolidone)/polydimethylsiloxane system (PB latex)] were compared, the complex polymer latex formed by the complexation of the PA latex with the PB latex had the best film‐forming performance, with formed coatings that were more smooth and had fewer less cracks. Also, compared to the two coatings formed by the two‐component polymer latices, the coatings formed by the complex polymer latex had a unique structure, a higher mechanical strength and elongation, a higher decomposing temperature, and better water resistance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1748–1754, 2003     

Miniemulsion and macroemulsion copolymerization of vinyl acetate with vinyl versatate

The miniemulsion and macroemulsion polymerization of vinyl acetate with vinyl versatate in batch and semibatch systems was investigated. Vinyl versatate was added either as an emulsion with the vinyl acetate, or as a neat liquid stream. In the batch runs, there is a poor dispersion of vinyl versatate during the nucleation period for the runs in which the vinyl versatate was added neat at the beginning of the polymerization. This led to smaller particles, lower polymerization rate, and different polymer composition evolution when compared with runs in which the vinyl versatate was emulsified with the vinyl acetate. In seeded semibatch runs, residual surfactant in the seed latex, along with the propensity for homogeneous nucleation in vinyl acetate emulsions, resulted in continuing nucleation during the entire semibatch interval. The polymerization rate was primarily affected by monomer feed rate rather than the feeding mode. The effect of monomer feeding mode on copolymer composition was weak when the semibatch feed rate was low, indicating some level of vinyl versatate mass transfer resistance. In all runs, only one glass transition temperature was observed, indicating effective copolymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2219–2229, 2002     

The structure and properties of acrylic‐polyurethane hybrid emulsions and comparison with physical blends

Aqueous acrylic‐polyurethane hybrid emulsions were prepared by semibatch emulsion polymerization of a mixture of acrylic monomers (butyl acrylate, methyl methacrylate, and acrylic acid) in the presence of polyurethane dispersion. Equivalent physical blends were prepared by mixing acrylic emulsion and polyurethane dispersion. The weight ratio between acrylic and polyurethane components varied to obtain different emulsion properties, microphase structure, and mechanical film properties of hybrid emulsions and physical blends. Particle size and molecular mass measurements, scanning electron microscopy, glass transition temperature, and rheological measurements performed characterization of the latex system. The mechanical properties were investigated by measuring tensile strength and Koenig hardness of dried films. The experimental results indicate better acrylic‐polyurethane compatibility in hybrid emulsions than in physical blends, resulting in improved chemical and mechanical properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 67–80, 2000     

环境友好型氟碳防锈乳液的制备研究

以丙烯酸丁酯、丙烯酸六氟丁酯、甲基丙烯酸十二氟庚酯、甲基丙烯酸为单体,可聚合含磷单体为功能单体合成了一种水性防锈氟碳乳液。乳液及其涂膜具有较好的综合性能,用该乳液配制的水性防锈涂料与普通苯丙乳液相比具有更优异的防锈性能。     

全丙乳液的合成及乳胶漆的制备

以甲基丙烯酸甲酯,丙烯酸丁酯为单体,用自制的乳化剂合成了全内乳液。配制了性能良好的乳胶漆,讨论了ＰＶＣ等因素对乳胶漆性能的影响。     

Aldehyde functional monomer as efficient cross-linkable comonomer with biobased phenols in acrylic coatings

Acrylic–styrenic coatings bearing reactive aldehyde functions were synthesized by copolymerization of vinylbenzaldehyde with methyl methacrylate, butyl acrylate and styrene comonomers. These polymers were cross-linked by phenol-aldehyde reaction with catechin, a natural and non-toxic phenolic compound. First, model studies confirmed that aldehyde functions on the polymer chain remain reactive toward phenolic compounds. Then, acrylic–styrenic oligomers were synthesized with different aldehyde function concentrations from 0 to 6%w and, tuning butylacrylate composition, with different glass transition temperatures for coating applications. Lastly, after screening those two parameters, the analytical tests of the cured coatings confirmed that this alternative cross-linking system gives a high level of performance with high cross-linking degree, high thermal stability, good adhesion properties and excellent impact resistance.     

非保护胶体稳定醋叔丙乳液及其乳胶漆耐擦洗性能的研究

通过乳液聚合法,使用叔碳酸乙烯酯类及丙烯酸酯类单体对醋酸乙烯酯进行改性共聚,以改善醋酸乙烯酯聚合物的缺点。在聚合过程中不使用传统的保护胶体,而采用乳化剂稳定技术制备了一种小粒径的醋叔丙(醋酸乙烯酯/叔碳酸乙烯酯/丙烯酸酯)乳液,并研究了其用于内墙高PVC(颜料体积浓度)乳胶漆时单体组成、乳液粒径、功能单体等因素对耐擦洗性能的影响。结果表明成功地开发了一种小粒径非保护胶体稳定的醋叔丙乳液,可以满足高PVC经济环保内墙乳胶漆乳液高耐擦洗性能要求。     

Synthesis and characterization of functionalized polymer latex particles through a designed semicontinuous emulsion polymerization process

Monodispersed noncarboxylated and carboxylated poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latices were synthesized with a well‐defined semicontinuous emulsion polymerization process. A modified theory to correlate the polymerization rate to the instantaneous conversion of the monomer or comonomer mixture was developed. The resulting equation was used to determine the maximum polymerization rate only below or equal to which the polymerization could be operated in the highly monomer‐starved regime, which corresponded to an instantaneous conversion of 90% or greater. Experimental data from reaction calorimetry supported that the polymerization was under highly monomer‐starved conditions when the model latices were synthesized with the modified model. The estimation of the average number of free radicals per latex particle(n?) during the feeding stage revealed that n? was as high as 1.4 in the actual polymerization, which showed that the original selection of 0.5 as the n? value was not accurate in the developed model. From the conductimetric titration experiments, we found that most of the carboxyl groups from the methacrylic acid (MAA) were buried inside the latex particles, and the surface carboxyl group coverage increased as the MAA concentration in the comonomer feed increased. The glass‐transition temperatures of the synthesized polymers were close to the designed value from the Pochan equation, and only one glass transition was observed in the polymer samples in the differential scanning calorimetry measurements, indicating a homogeneous copolymer composition in the functionalized shell. Particle size characterization and transmission electron microscopy confirmed the uniformity in the latex particle size. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 248–256, 2005     

Preparation and performance in paper coating of silicone‐modified styrene–butyl acrylate copolymer latex

Silicone‐modified styrene–butyl acrylate copolymer latex was synthesized by emulsion copolymerization by using octamethylcyclotetrasiloxane (D₄), styrene, and butyl acrylate as raw materials, potassium persulfate as initiator and propylmethacrylate triethoxysilane (KH‐570) as crosslinking agent. The infrared spectra studies showed that the vinyl monomers were completely copolymerized with D₄. The prepared silicone‐modified copolymer latex with the interpenetrating polymer networks tended to have higher stability, and better toluene and water resistance than styrene–butyl acrylate latex. The glossiness of coated paper was improved with silicone‐modified copolymer latex, and it was at a maximum when D₄ was about 3% of total monomers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 333–336, 2001     

Preparation and Adhesion Property of a Low Temperature Cross-Linkable Vinyl Acetate-Acrylate Copolymer Latex

The functional acrylate monomer (FAM) containing an amino group was synthesized by using glycidyl methacrylate (GMA) and ammonia. FAM was then copolymerized with Vinyl acetate and other acrylate monomers by emulsion copolymerization. The cross-linkable latex was obtained by adding a set content of glutaraldehyde to the earlier copolymer emulsion. The FT-IR results show that the cross-linking reaction between amino and aldehyde groups is detected during the curing process of copolymer. The glass transition temperature (T_g) of the copolymer can be evidently increased from ?16.2 to ?8.7°C as the FAM alters from 0 to 10%. T-peel strength of the polyethylene-polyethylene (PE-PE) packaging films laminated by products was studied. The results show peel strength dramatically increases with the cross-linking density at room temperature, and still reaches 2.5 N·15 mm^?1 even at 60°C, which can satisfy the application requirement enough.     

Synthesis of well‐defined,functionalized polymer latex particles through semicontinuous emulsion polymerization processes

The design of a semicontinuous emulsion polymerization process, primarily based on theoretical calculations, has been carried out with the objective of achieving overall independent control over the latex particle size, the monodispersity in the particle size distribution, the homogeneous copolymer composition, the concentration of functional groups (e.g., carboxyl groups), and the glass‐transition temperature with n‐butyl methacrylate/n‐butyl acrylate/methacrylic acid as a model system. The surfactant coverage on the latex particles is very important for maintaining a constant particle number throughout the feed process, and this results in the formation of monodisperse latex particles. A model has been set up to calculate the surfactant coverage from the monomer feed rate, surfactant feed rate, desired solid content, and particle size. This model also leads to an equation correlating the polymerization rate to the instantaneous conversion of the monomer or comonomer mixture. This equation can be used to determine the maximum polymerization rate, only below or at which monomer‐starved conditions can be achieved. The maximum polymerization rate provides guidance for selecting the monomer feed rate in the semicontinuous emulsion polymerization process. The glass‐transition temperature of the resulting carboxylated poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) copolymer can be adjusted through variations in the compositions of the copolymers with the linear Pochan equation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 30–41, 2003     

遮盖聚合物的制备及其在水性涂料中的应用

合成了一种中空徽球遮盖聚合物?采用扫描电子显微镜分析了所合成遮盖聚合物的形貌结构，并对采用该遮盖聚合物的水性涂料的配方作了简单研究。该遮盖聚合物在有光乳胶漆中可以部分替代钛白粉，降低成本；即使在工程乳胶漆中，加少量该遮盖聚合物也可以适当提高涂层的耐洗刷性能。