Toughness,dynamic mechanical property,and morphology of polyvinylchloride/acrylonitrile‐styrene‐butyl acrylate blends

Acrylonitrile‐styrene‐butyl acrylate (ASA) graft copolymers with different acrylonitrile (AN) contents, the core‐shell ratio, and tert‐dodecyl mercaptan (TDDM) amounts were synthesized by seed emulsion polymerization. Polyvinylchloride (PVC)/ASA blends were prepared by melt blending ASA graft copolymers with PVC resin. Then the toughness, dynamic mechanical property, and morphology of the PVC/ASA blends were investigated. The results indicated that the impact strength of the PVC/ASA blends increased and then decreased with the increase of the AN content in poly(styrene‐co‐acrylonitrile (SAN) copolymer, and increased with the increase of the core‐shell ratio of ASA. It was shown that brittle‐ductile transition of PVC/ASA blends was dependent on poly(butyl acrylate) (PBA) rubber content in blends and independent of AN content in SAN copolymer. The introduction of TDDM made the toughness of PVC/ASA blends poor. Dynamic mechanical analysis (DMA) curves exhibited that PVC and SAN copolymers were immiscible over the entire AN composition range. From scanning electron microscopy (SEM), it was found that the dispersion of ASA in PVC/ASA blends was dependent on the AN content in SAN copolymer and TDDM amounts. J. VINYL ADDIT. TECHNOL., 22:43–50, 2016. © 2014 Society of Plastics Engineers     

Morphology of poly(butyl acrylate)/poly(styrene‐co‐methyl methacrylate) latex prepared by starved emulsion polymerization: II. Development of particle morphology

Heterogeneous latexes were prepared by a two‐stage seeded emulsion polymerization process under monomer starved conditions at 80 °C using potassium persulfate as the initiator and sodium dodecyl sulfate as the emulsifier. Poly(butyl acrylate) latexes were used as seeds. The second‐stage polymer was poly(styrene‐co‐methyl methacrylate). By varying the amount of methyl methacrylate (MMA) in the second‐stage copolymer, the polarity of the copolymer phase could be controlled. It was found that the latex particles displayed different morphologies depending on the monomer ratio. The amount of MMA had a significant effect on the evolution of morphology. The morphologies were observed by transmission electron microscopy. In addition, the evolution of the particle morphology was predicted by the mathmatical model for cluster migration. The model gave the same trends as the experimental results. © 2002 Society of Chemical Industry     

Preparation and properties of polystyrene‐g‐poly(butyl acrylate) copolymer emulsions with ultrasonic radiation. I. Preparation technology and coagulum ratio

A stable emulsion of polystyrene‐g‐poly(butyl acrylate) was prepared via the following steps: (1) foam polystyrene waste was dissolved in butyl acrylate; (2) the solution was added to an aqueous solution of sodium dodecyl sulfate, ammonium persulfate, and sodium hydrogen bicarbonate; and (3) the mixture was emulsified and graft‐copolymerized by ultrasonic radiation and agitation. Then, the effects of various factors, such as the strength and time of the ultrasonic radiation, the type and dosage of the emulsifier, the concentrations of the initiator and butyl acrylate, the quantity of acrylic acid, and the reaction temperature, on the coagulum ratio were investigated and analyzed. As a result, a suitable technology for reducing the amount of coagulum could be proposed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1405–1409, 2005     

Preparation and properties of poly(WPSF‐co‐butyl acrylate) copolymer emulsion with ultrasonic radiation II. Monomer conversion rate and characterization

A stable emulsion of poly(WPSF‐co‐butyl acrylate) based on butyl acrylate, waste polystyrene foam was synthesized through emulsion polymerization using sodium dodecyl sulfate and octyl phenyl polyoxyethylene ether as surfactant, ammonium persulfate and sodium hydrogen bisulfate as mixed redox initiator, under ultrasound irradiation in the absence of inert gas. The effects of various copolymerization conditions on the monomer conversion were reported. The copolymers were characterized by means of IR, ¹HNMR, and gel permeation chromatography. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Properties of PHMS‐g‐p [butylacrylate (BA)‐N‐hydroxyl‐methyl acrylamide (NMA)] graft copolymer emulsions

Emulsion graft copolymerization of poly(hydrogenmethylsiloxane) (PHMS) and butyl acrylate (BA) in the presence of functional comonomer N‐hydroxyl‐methyl acrylamide (NMA) was conducted by batch emulsion copolymerization to modify the properties of polysiloxane. Morphology of graft copolymer particles was characterized by transmission electron microscopy. The effect of polymerization method, PHMS content, initiator concentration, and NMA content on stability of emulsion, morphology, size of particle, and rheological properties were investigated. It has been found that stability of emulsion is better by semicontinuous emulsion polymerization than that of batch emulsion polymerization and it increased with increasing PHMS‐NMA concentration. Increasing PHMS concentration and NMA concentration, the particle size and the viscosities increase. The property of resistance to electrolytes of graft copolymer emulsions and swelling property of film were also discussed. Results showed PHMS‐g‐P [butylacrylate (BA)‐N‐hydroxyl‐methyl acrylamide (NMA)] graft copolymer emulsion has good resistance to electrolytes and the water absorption of its film increases with increasing BA‐NMA content grafted onto PHMS. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2209–2217, 1999     

Novel method of preparation of a charged mosaic membrane by using dipole‐like microspheres. II. Preparation of dumbbell/egg‐like microspheres

The dumbbell‐like/egglike microspheres of poly(4‐vinylpyridine/n‐butyl acrylate)/polystyrene [P(4VP/nBA)/PS] were prepared by soap‐free seed emulsion polymerization. The effects of various polymerization parameters, such as the amount of ethyl acetate (EA) in the continuous phase, swelling time, degree of crosslinking of seed polymer, polymerization temperature, and compatibility of seed polymer and the secondary polymer, and so forth, on the formation of dumbbell‐like/egglike morphology were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that secondary particles could be eliminated either by drastically increasing the number of seed particles or by stripping EA from the seed latex by dialysis and evaporation under a vacuum. Swelling the seed particle with the secondary monomer was essential for the preparation of egglike microspheres. For the localization of PS domains on one side of the egglike particle, the most effective factors were to elevate the polymerization temperature up to 90°C and simultaneously to lower the compatibility of the polymer on the seed particle surface with the phase of PS, while using the uncrosslinked seed latex. Crosslinking the seed latex was not suitable for localizing the PS domains in the seed particle, especially when the degree of crosslinking exceeded 0.5 wt % of EGDMA. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2002–2017, 2001     

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     

丙烯酸酯乳液胶粘剂的合成及其性能研究

以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯腈(AN)和丙烯酸(AA)为单体,十二烷基硫酸钠(SDS)为乳化剂,过硫酸钾(KPS)为引发剂,通过半连续乳液聚合方法合成了丙烯酸酯乳液胶粘剂。研究了软硬单体配比、不同硬单体以及功能单体AA对胶粘剂性能的影响。研究结果表明,当m(BA)∶m(MMA)∶m(AN+St)=75∶15∶10[其中m(AN)∶m(St)=1∶3]、w(AA)=2份时,制备的乳液胶粘剂具有较好的剪切强度、拉伸强度和耐水性。     

Morphologies of polybutylacrylate/poly(styrene‐co‐methyl methacrylate) latex prepared by starved emulsion polymerization Part I. Thermodynamics equilibrium morphology

Heterogeneous latexes were prepared by a semicontinuous seeded emulsion polymerization process under monomer starved conditions at 80 °C using potassium persulfate as the initiator and sodium dodecyl sulfate as the emulsifier. Poly(butyl acrylate) latexes were used as seeds. The second‐stage polymer was poly(styrene‐co‐methyl methacrylate). By varying the amounts of methyl methacrylate (MMA) in the second‐stage copolymer, the polarity of the copolymer phase could be controlled. Phase separation towards the thermodynamic equilibrium morphology was accelerated either by ageing the composite latex at 80 °C or by adding a chain‐transfer agent during polymerization. The morphologies of the latex particles were examined by transmission electron microscopy (TEM). The morphology distributions of latex particles were described by a statistical method. It was found that the latex particles displayed different equilibrium morphologies depending on the composition of the second‐stage copolymers. This series of equilibrium morphologies of [poly(butyl acrylate)/poly(styrene‐co‐methyl methacrylate)] (PBA/P(St‐co‐MMA)) system provides experimental verification for quantitative simulation. Under limiting conditions, the equilibrium morphologies of PBA/P(St‐co‐MMA) were predicted according to the minimum surface free energy change principle. The particle morphology observed by TEM was in good agreement with the predictions of the thermodynamic model. Therefore, the morphology theory for homopolymer/homopolymer composite systems was extended to homopolymer/copolymer systems. © 2002 Society of Chemical Industry     

丙烯酸酯乳液的合成及改性研究

以丙烯酸丁酯(BA)和丙烯酸-2-乙基己酯(2-EHA)为软单体、甲基丙烯酸甲酯(MMA)为硬单体、丙烯酸(AA)为功能单体、甲基丙烯酸羟乙酯(HEMA)为交联单体和十二烷基硫酸钠(SDS)/乳化剂(OP-10)为阴/非离子型复合乳化剂,采用核/壳种子乳液聚合法制备了丙烯酸酯共聚乳液;然后在壳层聚合时寸加入HEMA,并用乙烯基有机硅进行改性,制得硅丙乳液。结果表明:当m(SDS):m(OP-10)=3:2、w(复合乳化剂)=3.4%、w(引发剂)=0.82%、w(HEMA)=3.5%、聚合温度为80℃以及聚合中期加入6.8%乙烯基硅油至壳单体中时,硅丙乳液及其胶膜的稳定性、耐水性和力学性能俱佳。     

氧化还原引发剂对丙烯酸酯乳液性能及聚合机制的影响

以过硫酸钾(KPS)和亚硫酸氢钠(NaHSO3)为自由基聚合体系的氧化-还原型引发剂,以十二烷基硫酸钠(SDS)和脂肪醇聚氧乙烯醚硫酸钠(AES)为阴/非离子型复合乳化剂,制备甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和甲基丙烯酸(MAA)共聚物乳液。研究了引发剂种类及用量对该乳液性能及聚合过程等影响,探讨并提出了酸性条件下丙烯酸酯乳液体系的新型引发机制。结果表明:在其他条件保持不变的前提下,当m(KPS):m(NaHSO3)=1.00:0.45、w(KPS+NaHSO3)=0.6%时,乳液的单体转化率(98%)和黏度(5.900 Pa.s)相对最高,反应时间(2.0 h)相对较短且初始聚合温度(60℃)相对最低,此时乳液质量最稳定。     

Templating synthesis of non‐spherical polymer particles and their effect on the fracture toughness of an epoxy‐amine network

Flexible non‐spherical polymer particles were successfully produced via concentrated emulsion polymerization. LUDOX TM‐50 (colloidal silica, 50 wt% suspension in water) was introduced into the continuous phase to strengthen the template and inhibit monomer diffusion between the continuous and dispersed phases. The extent of non‐spherical shape was identified by the roundness value. Transmission electron micrographs showed that the higher the volume fraction of the dispersed phase became, the more non‐spherical were the poly(butyl acrylate) (PBA) particles. As an application, the effect of the non‐spherical particles on the fracture toughness of a modified epoxy‐amine network was studied. Scanning electron micrographs showed that the introduction of the non‐spherical PBA particles improved efficiently the impact strength of the cured epoxy resin. Copyright © 2006 Society of Chemical Industry     

The effects of acrylate monomers and polystyrene addition on the morphology of DOP‐plasticized styrene–acrylate polymer particles prepared by SPG emulsification and suspension polymerization

Fairly uniform copolymer particles of methyl acrylate (MA), butyl acrylate (BA), or butyl methacrylate (BMA) were synthesized via Shirasu porous glass (SPG) membrane and followed by suspension polymerization. After a single‐step SPG emulsification, the emulsion composed mainly of the monomers. Hydrophobic additives of dioctyl phthalate (DOP), polystyrene molecules, and an oil‐soluble initiator, suspended in an aqueous phase containing poly(vinyl alcohol) (PVA) stabilizer and sodium nitrite inhibitor (NaNO₂), were subsequently subjected to suspension polymerization. Two‐phase copolymers with a soft phase and a hard phase were obtained. The composite particles of poly(St‐co‐MA)/PSt were prepared by varying the St/PSt ratios or the DOP amount. The addition of PSt induced a high viscosity at the dispersion phase. The molecular weight slightly increased with increasing St/PSt concentration. The multiple‐phase separation of the St‐rich phase and PMA domains, observed by transmission electron microscopy, was caused by composition drift because the MA reactivity ratio is greater than that of St. The addition of DOP revealed the greater compatibility between the hard‐St and soft‐MA moieties than that without DOP. The phase morphologies of poly(St‐co‐MA), poly(St‐co‐BMA), and their composites with PSt were revealed under the influence of DOP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1195–1206, 2006     

Concentrated emulsion copolymerization of butyl acrylate and vinyl acetate initiated by a redox initiator at lower temperature

The concentrated emulsion copolymerization of butyl acrylate and vinyl acetate with an ammonium persulfate/sodium hydrogen sulfate mixture as a redox initiator, with a sodium dodecyl sulfate/cetyl alcohol mixture as a compound surfactant, and with poly(vinyl alcohol) as a liquid film reinforcer was carried out at lower temperature. In less than 3 h, the polymerization conversion was greater than 95%. The effects of the surfactant, the initiator, the volume fraction of the monomer, and the temperature on the stability of the concentrated emulsion, the kinetic process, and the average size of the latices were examined. The morphology of the polymer particles was observed by transmission electron microscopy, and the average size and distribution of the particle diameter were measured by photon correlation spectroscopy. The kinetic equation was R_p = k[M]^0.38[I]^0.89[E]^?0.80 at 30°C (where R_p is the polymerization rate, [I] is the initiator concentration, [M] is the monomer concentration, and [E] is the concentration of the compound surfactant), and the apparent activation energy was 22.69 kJ/mol. The thin‐layer polymerization of the concentrated emulsions, which enabled the removal of the heat of polymerization, was performed first. In comparison with test‐tube polymerization, thin‐layer polymerization provided a more regular morphology of the polymer particles. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 570–576, 2004     

Synthesis of graft copolymer of styrene and acrylonitrile onto poly (butyl acrylate) by using polymeric peroxide

Summary Two-stage seeded emulsion copolymerization of butyl acrylate with tert-butyl 3-isopropenylcumylperoxide (D120) was performed at 70°C . Copolymer latex with 0.2μm of particle size was obtained. Emulsion graft polymerization of styrene and acrylonitrile onto the copolymer of butyl acrylate was initiated by peroxy bonds in the D120 units of the backbone chains at 120°C . Graft copolymers with higher grafting ratio were derived. It was found that the grafting ratio tends to increase with the increasing D120 in feed of copolymerization with butyl acrylate. The graft copolymers were blended with SAN resin, and a kind of AAS resin was obtained. Both elongation at break and Izod impact strength of the AAS resin reached maximum at grafting ratio of 0.25, which were comparable with the values of ABS resin for general purpose. A method to improve the grafting efficiency on the saturated polyacrylate elastomer rubber was developed. Received: 6 March 2002 / Revised version: 8 May 2002 / Accepted: 13 May 2002     

High monomer content batch microemulsion polymerization of butyl acrylate and acrylonitrile initiated with gamma ray

Gamma ray-induced polymerization of butyl acrylate (BA) and acrylonitrile (AN) was carried out at room temperature in a microemulsion with high monomer content stabilized by a mixture of sodium of 12-acryloxy-9-octadecenoic acid (AOA) and sodium dodecyl sulfate (SDS) at a weight ratio of 4. Special Y-shaped structure of AOA promotes the efficiency of monomer solubilization and gamma ray radiation contributes to the stability of microemulsion during the polymerization process. Microlatexes were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Results showed that microlatex particles with a narrow size distribution were obtained. The effects of monomer composition, dose rate, monomer concentration, and surfactant concentration on the microlatexes are discussed.     

Preparation and characterization of polysiloxane–polyacrylates composite latices and their film properties

Gamma‐ray induced seeded emulsion polymerization of methyl methacrylate and butyl acrylate was carried out in the presence of a polymerizable polysiloxane seed latex, obtained by ring‐opening copolymerization of octamethyl cyclotetrasiloxane (D₄) and tetramethyl tetravinyl cyclotetrasiloxane (VD₄), catalyzed by dodecylbenzene sulfonic acid (DBSA). A series of polysiloxane seed latices with different molecular weights, vinyl contents and particle sizes was used. The conversion–time curve showed that the polymerization rate was accelerated significantly by the seed latex. The obtained composite latices also showed good storage stability, mechanical stability and high electrolyte resistance ability. By using transmission electron microscopy (TEM), the morphology of the composite latex particles was found to display a quite uniform fine structure. The graft polymerization reactions between the polymerizable polysiloxane and the acrylates were confirmed by Fourier‐transform infrared spectroscopy (FT‐IR) and the graft efficiencies were also studied. The influence of seed content, molecular weight, vinyl content of the polysiloxane and seed latex particles size on the mechanical performance, water absorption ratio, surface properties and transparency of the latex films was also investigated. It was found that the seed content and particles size greatly affect the mechanical performance, water absorption ratio and transparency of the latex films. Copyright © 2005 Society of Chemical Industry     

Stability and copolymerization of concentrated emulsion of styrene and butyl acrylate in the presence of polyurethane macromonomer

A study has been made of the stability and copolymerization of concentrated emulsion of styrene (St) and butyl acrylate (BA) in the presence of polyurethane macromonomer (DPUA), which contains C?C at one end. First, the DPUA macromonomer was synthesized from the appropriate amount of 2,4‐diisocyanate (TDI), polypropylene glycol (PPG), 2‐hydroxyethyl methylacrylate (HEMA), dimethylolpropionic acid (DMPA), and triethylamine (TEA) by four steps. Then, the DPUA was dissolved in St‐BA monomer mixtures. The DPUA/St‐BA concentrated emulsion copolymerization using sodium dodecyl sulfate/cetyl alcohol (SDS/CA) as composite surfactant and polyvinyl alcohol (PVA) as liquid film reinforcer, and ammonium persulfate/sodium hydrogen sulfate (APS/SHS) as redox initiator system was carried out at 30°C. The effect of NCO/OH molar ratio, surfactants' concentration, mass ratio of DPUA/St‐BA, initiators' concentration, volume fraction of the monomer phase (Φ), and temperature on the stability or the copolymerization of the concentrated emulsion of DPUA/St‐BA were investigated. The average size and distribution of the latex particles obtained under different conditions were also analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1992–1999, 2007     

硅丙微乳液的合成与性能研究

以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和有机硅(KH-560)为共聚单体,十二烷基硫酸钠(SDS)和辛基酚聚氧乙烯醚(OP-10)为复合乳化剂,采用种子乳液聚合法制备硅丙微乳液。通过单因素试验法优选出制备硅丙微乳液的最佳工艺条件。结果表明:当聚合反应温度为80℃、反应时间为3 h、m(BA)∶m(MMA)=4∶3、w(KH-560)=8%、复合乳化剂中m(OP-10)∶m(SDS)=1∶2且w(复合乳化剂)=3%时,单体转化率超过70%,硅丙微乳液具有良好的稳定性和耐介质性能。     

反应型乳化剂的合成及其在乳液聚合中的应用

合成了2类可聚合乳化剂马来酸酐单酯硫酸钠和马来酸酐单酯磺酸钠，测定了产物的纯度和临界胶束浓度，研究了它们在苯乙烯/丙烯酸丁酯/丙烯酸三元乳液聚合中的转化率。以十二烷基硫酸钠为参照物，用可聚合乳化剂制备的乳液对电解质的稳定性有很大的提高，干胶膜的耐水性和拉伸强度得到了显著改善。