Colloidal properties of copolymer‐encapsulated and surface‐modified pigment dispersion and its application in inkjet printing inks

A styrene–maleic acid copolymer (PSMA)‐encapsulated 2‐[(2‐methoxy‐4‐nitrophenyl) azo]‐N‐(2‐methoxyphenyl)‐3‐oxobutyramide (PY74) dispersion was prepared by the phase‐separation technique. A surface‐modified PY74 dispersion was prepared with PSMA sodium as a dispersant by the milling method. Furthermore, the two dispersions were applied to formulate pigment inks. The colloidal properties of these two dispersions were compared. The printing and color performance of the prepared inks were also investigated. The results show that the PSMA‐encapsulated PY74 dispersion with a small particle size had higher stabilities of NaCl concentration, pH value, and temperature than the surface‐modified PY74 dispersion. The apparent viscosity of the PSMA‐encapsulated PY74 dispersion changed little, while it changed greatly in the surface‐modified PY74 dispersion with an increase of the shear rate from 10 to 100 s⁻¹. The ink printing and color performance of printed Fabrics indicated that the PSMA‐encapsulated PY74 dispersion was more suitable for the preparation of inkjet printing ink than the surface‐modified PY74 dispersion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation of cationic pigment dispersions by surface grafting of polystyrene‐maleic anhydride with glycidyltriethylammonium chloride

Novel cationic pigment dispersions, which have potential uses in inkjet inks and coloration of textile and paper, were prepared by grafting quarternary ammonium groups onto the surface of polystyrene‐maleic anhydride encapsulated C. I. pigment yellow 14 (PY 14) powder. It is shown that the Zeta potentials greatly rely on the reaction time and temperature. And also, when the weight ratio of glycidyltriethylammonium chloride (GTA) to encapsulated PY 14 powder was 3 : 1, the Zeta potential of modified pigment dispersion reached to + 35.05 mV. Just due to the high Zeta potential of the prepared cationic pigment dispersions, the prepared cationic pigment dispersion shows good dispersion stability and a narrow size distribution with the average particle size of 202.9 nm. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Properties of copper phthalocyanine blue encapsulated with a copolymer of styrene and maleic acid

Copper phthalocyanine blue was encapsulated with a copolymer of styrene and maleic acid (PSMA) via a phase‐separation technique, and a PSMA‐encapsulated pigment dispersion was prepared. The effects of the additive on the stability of the dispersion were studied. Scanning electron microscopy photographs revealed that the particles in the PSMA‐encapsulated pigment dispersion were more uniform than those in a PSMA‐dispersed pigment dispersion. X‐ray photoelectron spectroscopy provided evidence that the PSMA‐encapsulated pigment acquired abundant carboxylic groups that could improve its wettability to water. Moreover, the results also indicated that the PSMA‐encapsulated pigment dispersion had improved color strength, its stability could be greatly influenced by the pH value and ion strength, and its apparent viscosity changed little with an increase in the shear rate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

St-MA-AA酯化改性高分子分散剂的合成与应用

以苯乙烯（St）、马来酸酐（MA）、丙烯酸（AA）为单体,采用溶液聚合法合成三元共聚物,并用正丁醇作酯化剂,对其进行部分酯化,制备出高分子分散剂St-MA-AA部分酯化物。将此分散剂应用于酞菁蓝颜料表面改性处理上,讨论了单体摩尔配比、分子量分布等因素对颜料平均粒径、Zeta电位、分散性（DE）和相对着色力（Kr）的影响。结果表明,St、MA、AA单体最佳摩尔比为1∶1∶0.5时,自制分散剂St-MA-AA部分酯化物与市售分散剂SMA1440相比,颜料的平均粒径降低了15%,Zeta电位上升了13%,离心稳定性升高了77%,着色力增加了9%,分散效果明显更好。     

Effects of alkali on properties of nanoscale 2,9 dimethyl quinacridone/poly(styrene‐maleic acid) composite dispersion

Nanoscale 2,9 dimethyl quinacridone (P.R.122) encapsulated by copolymer of styrene and maleic acid (PSMA) was prepared via phase separation technique followed by the preparation of composite dispersions. Experimental results showed that sodium hydroxide provided the dispersion the smallest particle size and the highest stability when compared with other additives, regardless of it being taken as dispersant or the other neutralization reagent. An optimal process was attained by using sodium hydroxide with a dosage of 0.60 times of molar amount of ? COOH groups in PSMA when P.R.122/PSMA composite dispersion was treated at 45°C for 30 min. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation of styrene‐maleic acid copolymers and its application in encapsulated pigment red 122 dispersion

Styrene‐maleic acid copolymers were synthesized by free radical polymerization. Encapsulated pigment red 122 dispersions were prepared by sedimentation with these copolymers. Effects of copolymer structure such as molar content of maleic acid, molecular weight, and the amount of copolymers on stability and particle size of dispersion were investigated. The results showed that encapsulated pigment dispersion with higher stability, smaller particle size, and narrower particle distribution could be achieved when the molar content of maleic acid was at 0.43 and the intrinsic viscosity was at 79.65 ml/g with amount of copolymers 10%. The encapsulated layer was about 5 nm which could be observed by TEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

乳液聚合法包覆酞菁蓝的制备及性能研究

在超细可聚合分散剂/酞菁蓝分散体中添加共聚单体和引发剂,采用乳液聚合法对酞菁蓝进行包覆。考察了共聚单体结构及用量、引发剂用量、反应温度和时间对包覆酞菁蓝性能的影响。结果表明,与甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)相比,苯乙烯(St)是较佳的包覆共聚单体,当St质量为颜料质量的20%,过硫酸铵(APS)质量为St与烯丙氧基壬基苯氧基丙醇聚氧乙烯磺酸铵(ANPS)总质量的1.0%,于70～80℃反应2 h时,所制备包覆酞菁蓝的粒径较小,稳定性较高。与未聚合分散体相比,包覆酞菁蓝的耐热稳定性、耐酸碱稳定性和离心稳定性均有明显提高,FTIR和TEM照片表明,酞菁蓝表面包覆了聚合物,且包覆酞菁蓝粒度分布更均匀。     

Encapsulation of disperse dye by phase separation technique using poly(styrene‐maleic acid)

C.I. disperse dye blue 60 was encapsulated by poly(styrene‐maleic acid) using phase separation technique, followed by the preparation of the encapsulated disperse dye dispersion. The effects of process conditions on particle size of the dispersion were investigated. The results showed that the particle size of the encapsulated disperse dye dispersion was small, and the stability was excellent when mass ratio of poly(styrene‐maleic acid) to disperse dye (R_p/d), dropping speed of phase separation agent (D_s), disperse dye content in dispersion (C_d), and dispersing time (D_t) were about 20%, 7 mL/min, 5–7.5%, and 1.5 h, respectively. Transmission electron microscope (TEM), zeta potentials, and contact angle indicated that C.I. disperse dye blue 60 was successfully encapsulated by poly(styrene‐maleic acid). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Investigation on preparation and property of nano‐CaCO3/PP masterbatch modified by reactive monomers

Nano‐CaCO₃/polypropylene (PP) masterbatch containing above 80 wt % nano‐CaCO₃ was prepared by nano‐CaCO₃ coated PP modified by reactive monomers. The chemical interaction, crystallization and melting behavior, thermal stability, morphology, and surface contact angle of masterbatch were investigated with IR, DSC, TEM, TGA, ESCA, and surface contact angle. The results indicated that nano‐CaCO₃ was coated by PP graft copolymers in the masterbatch modified by reactive monomers. The graft ratio and crystallization and melting behavior of PP in the masterbatch depended on the type and content of reactive monomer. The crystallization temperatures of masterbatch modified by reactive monomer is methyl methacrylate > butyl acrylate > methyl acrylate ≈ mixture of acrylic acid and styrene > unmodified ≈ maleic anhydride ≈ acrylic acid > styrene. Modification by reactive monomer increased the thermal stability and surface contact angle of masterbatch. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3907–3914, 2006     

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH₄OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO₂. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO₂ particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007     

Comparison of properties of acrylic–polyurethane hybrid emulsions prepared by batch and semibatch processes with monomer emulsion feed

Aqueous acrylic–polyurethane hybrid emulsions were prepared by batch and semibatch polymerization of acrylic monomer mixtures (butyl acrylate, methyl methacrylate and acrylic acid) in the presence of polyurethane dispersion. The acrylic component was introduced in the monomer emulsion feed. The weight ratio between acrylic and polyurethane components was varied to obtain different emulsion properties, microphase structure and mechanical film properties. Scanning electron microscopy, average particle size and molecular weight measurements were performed to characterize the latex systems. Mechanical properties were examined by measuring Koenig hardnesses of dried films. The average particle size increased with the acrylic/polyurethane ratio. Particles of larger than average size and, to some extent, higher than average molecular weights by batch process were formed. Koenig hardnesses decreased with increasing acrylic/polyurethane ratio. Properties of emulsions synthesized by semibatch processes were compared with the results reported for a different polyurethane dispersion. Copyright © 2003 Society of Chemical Industry     

溶液聚合法合成苯乙烯-马来酸酐交替共聚物

在过氧化苯甲酰(BPO)引发下,以丁酮为溶剂,采用溶液聚合法合成了苯乙烯-马来酸酐共聚物,并详细研究了温度、引发剂用量、苯乙烯与马来酸酐配比、单体(苯乙烯与马来酸酐)质量分数及聚合时间对聚合反应的影响。研究表明,在温度80℃,x(BPO)=0.6%(相对于苯乙烯与马来酸酐),n(苯乙烯)∶n(马来酸酐)=1∶1,w(单体)=15%(相对于混合溶液),反应时间4 h的条件下,聚合物收率可达99%。采用13CNMR、IR、GPC、元素分析对共聚物结构进行了表征。利用TG测定了其热稳定性。结合共聚物的元素分析与13CNMR的分析结果,表明合成的苯乙烯-马来酸酐共聚物是一种交替共聚物。     

微米级单分散聚苯乙烯微球的制备

以苯乙烯(St)为单体、偶氮二异丁腈(AIBN)为引发剂、聚乙烯吡咯烷酮(PVP)为分散稳定剂,在乙醇-水反应介质中,采用分散聚合法制备了微米级单分散聚苯乙烯(PS)微球。分别用电镜扫描和激光粒度仪表征了PS微球表面形貌、粒径及粒度分布,探讨了影响PS微球粒径及粒度分布的诸多因素。结果表明,AIBN用量(以单体质量计,下同)大于5.0%或PVP用量(以单体质量计,下同)小于2%时,PS粒子间有聚并现象;当St浓度为10%、AIBN用量为2.5%、PVP用量为5.5%、醇水质量比为90∶10、聚合温度为70℃时,制备的PS微球粒径为1.612μm、粒度分散系数为0.357,微球单分散性及球形度最佳。     

Particle formation mechanism in radical polymerization in miniemulsion based on in situ surfactant formation without high energy homogenization

Conventional radical polymerization of styrene at 70 °C in aqueous miniemulsion generated using the in situ surfactant technique, without use of high energy mixing, has been investigated in detail. The surfactant potassium oleate was formed in situ by reaction between oleic acid and potassium hydroxide at the styrene/water interface. The particle formation mechanism was investigated by use of pyrene as a probe, revealing that under suitable conditions with an oil-phase initiator, particle formation occurs primarily via monomer droplet nucleation. The droplet/particle stability is however inferior to that in a typical miniemulsion generated employing ultrasonication, as manifested by a marked increase in droplet/particle size with conversion and a bimodal droplet/particle size distribution by weight. The droplet/particle stability increases with increasing amount of oleic acid, hexadecane, water, and the ratio potassium hydroxide:oleic acid, respectively.     

Effect of GMA on monodisperse epoxy‐functionalized polymer microsphere particles by dispersion copolymerization of styrene with glycidyl methacrylate

Monodisperse poly[styrene‐co‐glycidyl methacrylate (GMA)] microparticles were synthesized by dispersion copolymerization in a water–ethanol medium. The effects of various polymerization parameters on the particle size and size distribution of the dispersion copolymerization were investigated. The dispersion of polymer particles decreased when the GMA was added if the polystyrene homopolymer particles were polydispersed. The GMA acted as a comonomer as well as a costabilizer in the dispersion copolymerization of styrene with GMA. The solvency of the monomer increased with the concentration of GMA in the polymerization medium because GMA has a greater hydrophilicity than styrene, resulting in a large particle size and a slow polymerization rate. From an HCl–dioxane analysis of the poly(styrene‐co‐GMA) microparticles, great amounts of epoxy groups were detected after the completion of dispersion copolymerization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1206–1212, 2001     

Preparation of reactive nanoscale carbon black dispersion for pad coloration of cotton fabric

A reactive dispersant (SMA–ESA) was synthesised from poly(styrene‐alt‐maleic anhydride) (SMA) and 4‐(beta‐sulfatoethylsulfonyl)aniline (ESA), and its dispersing ability for carbon black (CB) was investigated. Fourier transform infrared (FTIR) and ¹H–nuclear magnetic resonance (NMR) spectroscopies showed that an amidation reaction took place between ESA and SMA. The optimal preparation conditions for reactive nanoscale CB dispersion were a mole ratio of ESA to SMA of 4:3, with a mass ratio of SMA–ESA and CB at 3%, sonication time 20 min, and pH 8. The reactive nanoscale CB dispersion prepared under optimal conditions showed excellent stability and small mean particle size. A cotton fabric coloured with reactive nanoscale CB dispersion could obtain a high K/S value, and excellent rubbing and washing fastness.     

Preparation and properties of polymer-encapsulated phthalocyanine blue pigment via emulsion polymerization

Polymer-encapsulated phthalocyanine blue pigment dispersion was prepared with a polymerizable dispersant by emulsion polymerization method, and the effect of preparation conditions on the particle size of dispersion was investigated. Dynamic light scattering measurement demonstrated that allyloxy nonyl-phenoxypropanolpolyoxyethyleneetherammonium sulfonate (ANPS) was suitable for phthalocyanine blue pigment modification. The polymer-encapsulated phthalocyanine blue pigment dispersion with the small particles was obtained when the mass ratio of ANPS to phthalocyanine blue pigment, styrene (St) to phthalocyanine blue pigment, and ammonium persulfate (APS) to St was about 0.2, 0.2, and 0.01, respectively. Transmission electron microscopy (TEM), Fourier transforms infrared spectra (FTIR) and thermogravimetric analyses (TGA) provided supporting evidences for the encapsulation of phthalocyanine blue pigment with the formed copolymer. The polymer-encapsulated phthalocyanine blue pigment dispersion showed excellent stabilities to freeze–thaw treatment and centrifugal force.     

Dispersion polymerization of n‐butyl acrylate

The dispersion polymerization of n‐butyl acrylate (BA) was investigated using alcohol/water mixtures as the dispersion medium, 4,4′ ‐azobis‐(4‐cyanopentanoic acid) as the initiator, and polyvinylpyrrolidone (PVP) as the stabilizer. The effects of polymerization parameters, such as the alcohol/water ratio in the medium and the type and concentration of the polymeric stabilizer, on the resulting particle size and size distribution were studied. The final particle size and the stability of the dispersion system were found to be greatly influenced by the type of alcohol used in the mixture; that is, methanol or ethanol, even though the apparent solubility parameters are almost the same for the two types of mixtures. Poly(butyl acrylate) particles with controlled size and size distribution (monodisperse), and gel content were successfully prepared in a 90/10 methanol/water medium. It was found that the particle size decreased with increasing initiator concentration. This is the opposite of what was previously reported in the dispersion polymerizations of styrene and methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2692–2709, 2002     

Control of monodisperse particle size of styrenic–acrylate copolymers in dispersion copolymerization

Syntheses of monodisperse poly[(styrene)‐co‐(n‐butyl acrylate)] and poly[(styrene)‐co‐(2‐ethylhexyl acrylate)] were carried out by dispersion polymerization. The reactions were performed in the mixed solvent of ethanol–water in the presence of azo‐bisisobutyronitrile and poly(N‐vinylpyrrolidone) as the initiator and dispersant, respectively. The effects of reaction parameters, that is the type and concentration of dispersant, ratio of the mixed solvent, reaction temperature, agitation rate, monomer composition between styrene and n‐butyl acrylate or 2‐ethylhexyl acrylate, crosslinking agent and reaction time on the particle size, size distribution and average molecular weights of the resulting copolymer were thoroughly investigated. The resulting copolymer particles were smooth on their spherical surface and the sizes were in the range 0.6–1.8 µm with a narrow size distribution. In most cases, a correlation between small particle sizes with high average molecular weights was observed. The average particle size generally increased with increasing reaction temperature, time and acrylate monomer content. In contrast, the particle size decreased as the molecular weight, concentration of dispersant, polarity of the medium or agitation rate was increased. The glass transition temperature (T_g) of the copolymers can be controlled by the mole ratio of the comonomer. The T_g values decreased when the content of acrylate monomers in the copolymer increased, and T_g values of the synthesized copolymer were in the range 66–102 °C. Instead of using n‐butyl acrylate monomer in the copolymerization, 2‐ethylhexyl acrylate copolymerization with styrene resulted in insignificant changes in the particle sizes but there were significant decreases in T_g values. In this study, the monodisperse particles can be obtained by monitoring the appropriate conditions regarding PVP K‐30 (2–8 wt%), ethanol/water (90/10 wt%), the reaction temperature (70 °C) and the agitation rate (100 rpm). © 2000 Society of Chemical Industry     

Synthesis of ultrafine poly(styrene‐maleic anhydride) and polystyrene fibers by electrospinning

Fiber formation from atactic polystyrene (aPS) and alternating poly(styrene‐maleic anhydride) (PSMA) synthesized by free radical polymerization (AIBN, 90°C, 4 h) were investigated by electrospinning from various solutions. aPS was soluble in dimethylformamide (DMF), tetrahydrofuran (THF), toluene, styrene, and benzene, whereas PSMA was soluble in acetone, DMF, THF, dimethylsulfoxide (DMSO), ethyl acetate, and methanol. aPS fibers could be electrospun from 15 to 20% DMF and 20% THF solutions, but not from styrene nor toluene. PSMA, on the other hand, could be efficiently electrospun into fibers from DMF and DMSO at 20 and 25%, respectively. Few PSMA fibers were, however, produced from acetone, THF, or ethyl acetate solutions. Results showed that solvent properties and polymer–solvent miscibility strongly influenced the fiber formation from electrospinning. The addition of solvents, such as THF, generally improved the fiber uniformity and reduced fiber sizes for both polymers. The nonsolvents, however, had opposing effects on the two polymers, i.e., significantly reducing PSMA fiber diameters to 200 to 300 nm, creating larger and irregularly shaped aPS fibers. The ability to incorporate the styrene monomer and divinylbenzene crosslinker in aPS fibers as well as to hydrolyze PSMA fibers with diluted NaOH solutions demonstrated potential for post‐electrospinning reactions and modification of these ultrafine fibers for reactive support materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009