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     

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     

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 of hemispherical poly(4‐vinylpyridine‐co‐butyl acrylate)/poly(styrene‐co‐butyl acrylate) composite microspheres by seeded preswelling emulsion polymerization

Seeded preswelling emulsion polymerization was carried out by using monodispersed poly(4‐vinylpyridine‐co‐butyl acrylate) [P(4VP‐BA)] particles as the seed, and styrene and butyl acrylate as the second‐stage monomers under different polymerization conditions, to obtain hemispherical polystyrene (PST)‐rich–P4VP‐rich microspheres. Prior to polymerization, toluene was added into the preswelling system together with the second‐stage monomers. It was found that, with the increase of the amount of toluene, the particle morphology showed a tendency toward desirable hemispherical structure, and the colloidal stability of composite latex was improved. When the weight ratio of toluene/seed latex was increased up to 7.5/40 (g/g), the stable hemispherical latex could be obtained. However, when toluene was not added, the coagulum formed on the wall of the reactor during polymerization, and the composite particles with multiple surface domains (such as sandwich‐like, popcorn‐like) were formed. In addition, the final morphology of composite particles was influenced by the polarity of the seed crosslinker and the hydrophilicity of the second‐stage initiator, which could affect the mobility of poly(styrene‐co‐butyl acrylate) [P(ST‐BA)] chains. The morphology development during the polymerization was investigated in detail, and a schematic model was derived to depict the formation mechanism of hemispherical P(4VP‐BA)/P(ST‐BA) composite microspheres. The results revealed that the mobility of the P(ST‐BA) chains influenced the diffusion of the P(ST‐BA) domains on the surface of the P(4VP‐BA) matrix. When the mobility of the P(ST‐BA) chains allowed small‐size P(ST‐BA) domains to coalesce into one larger domain, complete phase‐separated morphology (hemisphere) could be achieved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3811–3821, 2003     

Film formation from pigmented latex systems: Mechanical and surface properties of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex blend films

The mechanical and surface properties of films prepared from model latex/pigment blends were studied using tensile tests, surface gloss measurements, and atomic force microscopy. Functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) [P(BMA/BA)] and ground calcium carbonate (GCC) were used as latex and extender pigment particles, respectively. The critical pigment volume concentration of this pigment/latex blend system was found to be between 50 and 60 vol % as determined by surface gloss measurement and tensile testing of the blend films. As the pigment volume concentration increased in the blends, the Young's modulus of the films increased. Nielsen's equations were found to fit the experimental data very well. When the surface coverage of carboxyl groups on the latex particles was increased, the yield strength and Young's modulus of the films both increased, indicating better adhesion at the interfaces between the GCC and latex particles. When the carboxyl groups were neutralized during the film formation process, regions with reduced chain mobility were formed. These regions acted as a filler to improve the modulus of the copolymer matrix and the modulus of the resulting films. The carboxyl groups on the latex particle surfaces increased the surface smoothness of the films as determined by surface gloss measurement. When the initial stabilizer coverage of the latex particles was increased, the mechanical strength of the resulting films increased. At the same time, rougher film surfaces also were observed because of the migration of the stabilizer to the surface during film formation. With smaller‐sized latex particles, the pigment/latex blends had higher yield strength and Young's modulus. Higher film formation temperatures strengthen the resulting films and also influence their surface morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4550–4560, 2006     

Interpolymer interactions and miscibility in poly(n‐butyl methacrylate‐co‐methacrylic acid)/poly(styrene‐co‐N,N‐dimethyl acrylamide) blends

The miscibility of poly(n‐butyl methacrylate‐co‐methacrylic acid) containing 18 mol % methacrylic acid (BMAM‐18) and poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 17 mol % N,N‐dimethyl acrylamide (SAD‐17) was investigated with viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. The DSC analysis showed a single glass‐transition temperature for all the blends, indicating that these copolymers were miscible over the entire composition range. The glass‐transition temperatures of these blends were higher than those calculated with the additivity rule. This was characteristic of the presence of specific interactions. The interactions between BMAM‐18 and the tertiary amide of SAD‐17 were studied with FTIR spectroscopy, which revealed that hydrogen‐bonding interactions occurred between the hydroxyl groups of BMAM‐18 and the carbonyl amide of SAD‐17. A new band characterizing these interactions appeared around 1613 cm^?1. The quantitative results showed that the fraction of the associated amide increased with an increase in the amount of the acidic BMAM‐18 copolymer. Although BMAM‐18 and SAD‐17 led to homogeneous solutions in butan‐2‐one, as the concentration of N,N‐dimethyl acrylamide increased to 32 mol % [as within the poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 32 mol % N,N‐dimethyl acrylamide], complexation occurred when this latter compound was mixed with BMAM‐18 in butan‐2‐one. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2717–2724, 2006     

Study on synthesis and morphology control of poly(4‐vinylpyridine‐co‐butyl acrylate)/poly(styrene‐co‐butyl acrylate) composite microspheres

Monodispersed crosslinked cationic poly(4‐vinylpyridine‐co‐butyl acrylate) [P(4VP‐BA)] seed latexes were prepared by soapless emulsion polymerization, using 2,2′‐azobismethyl(propionamidine)dihydrochloride (V₅₀) as an initiator and divinylbenzene (DVB) or ethylene glycol dimethacrylate (EGDMA) as a crosslinker. The optimum condition to obtain monodispersed stable latex was investigated. It was found that the colloidal stability of the P4VP latex can be improved by adding an adequate amount of BA (BA/4VP = 1/4, w/w), and adopting a semicontinuous monomer feed mode. Subsequently, poly(4‐vinylpyridine‐co‐butyl acrylate)/Poly(styrene‐co‐butyl acrylate) [P(4VP‐BA)/P(ST‐BA)] composite microspheres were synthesized by seeded polymerization, using the above latex as a seed and a mixture of ST and BA as the second‐stage monomers. The effects of the type of crosslinker, the degree of crosslinking, and the initiators (AIBN and V₅₀) on the morphology of final composite particles are discussed in detail. It was found that P(4VP‐BA)/P(ST‐BA) composite microspheres were always surrounded by a PST‐rich shell when V₅₀ was used as initiator, while sandwich‐like or popcorn‐like composite particles were produced when AIBN was employed. This is because the polarity of the polymer chains with AIBN fragments is lower than for the polymer with V₅₀ fragments, hence leading to higher interfacial tension between the second‐stage PST‐rich polymer and the aqueous phase, and between PST‐rich polymer and P4VP‐rich seed polymer. As a result, the seed cannot be engulfed by the PST‐rich polymer. Furthermore, the decrease of T_g of the second‐stage polymer promoted phase separation between the seeds and the PST‐rich polymer: sandwich‐like particles formed more preferably than popcorn‐like particles. It is important knowledge that various morphologies different from PST‐rich core/P4VP‐rich shell morphology, can be obtained only by changing the initiator, considering P4VP is much more hydrophilic than PST. The zeta potential of composite particles initiated by AIBN in seeded polymerization shifted from a positive to a negative charge. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1190–1203, 2002     

n‐Butyl acrylate based latex interpenetrating polymer networks used as processing modifiers and impact modifiers of poly(vinyl chloride)

A latex interpenetrating polymer network (LIPN), consisting of poly(n‐butyl acrylate), poly(n‐butyl acrylate‐co‐ethylhexyl acrylate), and poly(methyl methacrylate‐co‐ethyl acrylate) and labeled PBEM, with 1,4‐butanediol diacrylate as a crosslinking agent was synthesized by three‐stage emulsion polymerization. The initial poly(n‐butyl acrylate) latex was agglomerated by a polymer latex containing an acrylic acid residue and then was encapsulated by poly(n‐butyl acrylate‐co‐ethylhexyl acrylate) and poly(methyl methacrylate‐co‐ethyl acrylate). A polyblend of poly(vinyl chloride) (PVC) and PBEM was prepared through the blending of PVC and PBEM. The morphology and properties of the polyblend were studied. The experimental results showed that the processability and impact resistance of PVC could be enhanced considerably by the blending of 6–10 phr PBEM. This three‐stage LIPN PBEM is a promising modifier for manufacturing rigid PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1168–1173, 2004     

Preparation and characterization of the complex latex formed through complexation of two polymer latexes with chemically complementary structure

In this study, the intermacromolecular complexation of two polymers with chemically complementary structures in the latex state and the interparticle interactions were probed. Two latexes—a polydimethylsiloxane (PDMS)/poly(vinyl acetate‐co‐butyl acrylate) system, named PA latex, and a PDMS/poly(methacrylic acid) system, named PB latex—were prepared by seeded emulsion polymerization and the complex latexes were obtained through complexation of the PA latex with the PB latex. The properties of the obtained complex latexes were investigated using surface tension and viscosity measurements. The surface structure and composition of coatings obtained from the latexes were analyzed by X‐ray photoelectron spectroscopy and scanning probe microscopy. The results confirmed that there are interactions between the (or groups in PA and the groups in PB. The interactions result in unique properties of the polymer latex and lead to a formation of a new structure of the coatings. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1405–1411, 2003     

Effect of 3‐aminopropyltriethoxysilane on properties of poly(butyl acrylate‐co‐maleic anhydride)/silica hybrid materials

The transparent poly(butyl acrylate‐co‐maleic anhydride)/silica [P(BA‐co‐MAn)/SiO₂] has been successfully prepared from butyl acrylate‐maleic anhydride copolymer P(BA‐co‐MAn) and tetraethoxysilane (TEOS) in the presence of 3‐aminopropyltriethoxysilane (APTES) by an in situ sol–gel process. Triethoxysilyl group can be readily incorporated into P(BA‐co‐MAn) as pendant side chains by the aminolysis of maleic anhydride unit of copolymer with APTES, and then organic polymer/silica hybrid materials with covalent bonds between two phases can be formed via the hydrolytic polycondensation of triethoxysilyl group‐functionalized polymer with TEOS. It was found that the amount of APTES could dramatically affect the gel time of sol–gel system, the sol fraction of resultant hybrid materials, and the thermal properties of hybrid materials obtained. The decomposition temperature of hybrid materials and the final residual weight of thermogravimetry of hybrid both increase with the increasing of APTES. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the morphology of hybrid materials prepared in the presence of APTES was a co‐continual phase structure. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 419–424, 1999     

Film formation from pigmented latex systems: Drying kinetics and bulk morphologies of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) blend films

The drying kinetics and bulk morphology of pigmented latex films obtained from poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex particles functionalized with carboxyl groups and ground calcium carbonate blends were studied. Latex/pigment blends with higher carboxyl group coverage on the latex particle surfaces dried faster than films with few or no carboxyl groups present. The latex/pigment dispersions also dried faster when there was more stabilizer present in the blend system because of the hydrophilic nature of the stabilizer. The net effect of increasing the pigment volume concentration in the blend system was to shorten the drying time. The bulk morphologies of the freeze‐fractured surfaces of the pigmented latex films were studied with scanning electron microscopy. Scanning electron microscopy analysis showed that increased surface coverage of carboxyl groups on the latex particles in the latex/pigment blends resulted in the formation of smaller pigment aggregates with a more uniform size distribution in the blend films. In addition, the use of smaller latex particles in the blends reduced the ground calcium carbonate pigment aggregate size in the resulting films. Scanning electron microscopy analysis also showed that when the initial stabilizer coverage on the latex particles was equal to 18%, smaller aggregates of ground calcium carbonate were distributed within the copolymer matrix of the blend films in comparison with the cases for which the initial stabilizer coverage on the latex particles was 8 or 36%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2267–2277, 2006     

Effect of the MMA content on the emulsion polymerization process and adhesive properties of poly(BA‐co‐MMA‐co‐AA) latexes

In the past work, the shear resistance of pure poly(n‐butyl acrylate) was low, even incorporation of inorganic filler, silica in the composition. It is well‐known that the copolymerization of n‐butyl acrylate (BA) with methyl methacrylate (MMA) will increase the glass transition temperature, and enhance the shear resistance of acrylic polymers. In the current work, the preparation of a series of acrylic water‐borne pressure‐sensitive adhesives (PSAs) with the controlled composition and structure for the copolymerization of BA and acrylic acid (AA) with different MMA contents, poly(BA‐co‐MMA‐co‐AA) was reported and its effects on adhesive properties of the latices were investigated. The latices of poly(BA‐co‐MMA‐co‐AA) were prepared at a solid content of 50% by two‐stage sequential emulsion polymerization, and this process consisted of a batch seed stage giving a particle diameter of 111 nm, which was then grown by the semicontinuous addition of monomers to final diameter of 303 nm. Dynamic light scattering (DLS) was used to monitor the particle diameters and proved that no new nucleation occurred during the growth stage. Copolymerization of BA with MMA raised the glass transition temperature (T_g) of the soft acrylic polymers, and had the effect of improving shear resistance, while the loop tack and peel adhesion kept relatively high. The relationship between pressure‐sensitive properties and molecular parameters, such as gel content and molecular weight, was evaluated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Hydrolyzable‐emulsifier‐containing polymer latices as dispersants and binders for waterborne carbon black paint

Poly(styrene‐co‐butyl methacrylate) and poly(styrene‐co‐butyl acrylate) latices were prepared by emulsion polymerization with alkali‐hydrolyzable and nonhydrolyzable cationic emulsifiers and were used as a dispersant and binder for waterborne carbon black (CB) paint. CB was dispersed in the latex solutions and then coated on filter paper pretreated with dilute aqueous Na₂CO₃ under mild conditions. The styrene (St)‐rich rigid copolymer latices easily dispersed the CB but fixed a little amount of the pigment on the paper surface. In contrast, the methacrylate‐ and acrylate‐rich soft latices tended to increase the adhesibility on it. We also demonstrated that the hydrolyzable‐emulsifier‐containing latices always had a higher adhesibility than the nonhydrolyzable‐emulsifier‐containing ones. Thus, the hydrolyzable‐emulsifier‐containing latices with an appropriate St content had the highest paintability, rapid adhesion, quick drying, reduced fading, superior fastness, and so on. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3869–3873, 2013     

Properties of n‐butyl methacrylate copolymer latex films derived from crosslinked latex particles

Films obtained from copolymer latexes of n‐butyl methacrylate (BMA) with a series of crosslinking monomers [i.e., a macromonomer crosslinker (Mac), ethylene glycol dimethacrylate (EGDMA), and aliphatic urethane acrylate] exhibited differences in their tensile properties and swelling behaviors. For P(BMA‐co‐EGDMA) copolymer, a dependence on the initiator type was obtained. It is postulated that the network microstructures for the various copolymers evolved as the result of the copolymerization reactions between the monomer pairs during the synthesis in the miniemulsion free‐radical copolymerization. These network microstructures are, therefore, hypothesized to influence the mechanical properties of the resultant films. Copolymers prepared with Mac were tough in comparison with copolymers made with EGDMA. The presence of longer linear or lightly crosslinked poly(n‐butyl methacrylate) (PBMA) chains and the looseness of the crosslinked network structures in the PBMA‐co‐Mac copolymers appear to be the factors responsible for the differences. All of the copolymer films disintegrated into swollen individual microgels when they were immersed in tetrahydrofuran. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 42–49, 2003     

Preparation of poly(styrene‐co‐butyl acrylate)/montmorillonite nanocomposite by emulsion polymerization: Characterization and nanoscratch behavior

Organic–inorganic hybrid poly(styrene‐co‐butyl acrylate)/organically modified montmorillonite (PSBA/organo‐MMT) latex particles have been prepared by in situ emulsion polymerization. The effects of modifier variety and the level of organo‐MMT have been investigated on the basis of the characteristics and mechanical properties of the resulting hybrid emulsion polymers. Although the more hydrophilic intercalated organic modifiers increased the latex particle size, the hydrophobic ones decreased the particle size. A more heterogeneous copolymer chain intercalation was seen by widespread XRD reflection as the organo‐MMT (organoclay) level increases. The tapping mode atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to determine the dispersion state of organoclay particles inside the nanocomposite copolymer films. Dynamic mechanical thermal analysis (DMTA) showed that adding the organoclay to the copolymer decreased the maximum loss tangent (tanδ) value and caused the shift to a lower temperature. Interestingly, the incorporation of organoclay decreased the glass storage modulus of the copolymer, while increased the rubbery storage modulus to some extent. In addition, a standard indenter for the nanoscratching of copolymer nanocomposite films was used under low applied loads of 150 and 250 μN. The nanoscratch results showed that incorporation of a 3 wt % hydrophobic organoclay, e.g., Closite15A, in the copolymer matrix enhanced considerably the near‐surface hardness and grooving resistance of the nanocomposite film at room temperature. In fact, copolymer nanocomposite films with higher near‐surface hardness and tanδ curve broadening exhibited more nanoscratch resistance through a specific variety of viscoelastic deformation, which did not create a bigger groove. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Film formation from polystyrene–poly(butyl acrylate‐co‐methyl methacrylate) latex blends

We have employed steady sate fluorescence (SSF) and UV‐visible (UVV) techniques to determine the film formation behavior of latex blends. Blend films were prepared from mixtures of a high‐T_g pyrene (P) labeled polystyrene (PS) latex and a low‐T_g copolymer of poly(butyl acrylate‐co‐methyl methacrylate) (BuA/MMA4). Eleven different blend films were prepared in various hard/soft latex compositions at room temperature and annealed at elevated temperatures above glass‐transition (T_g) temperature of polystyerene for 10 min. Fluorescence intensity (I_P) from P was measured after each annealing step to monitor the stages of film formation. The evolution of transparency of latex films was monitored using photon transmission intensity, I_tr. Film morphologies were examined by atomic force microscopy (AFM). A significant change occurs in both I_P and I_tr intensities at a certain critical weight fraction of hard latex (R_c = 0.3). Above R_c, two distinct film formation stages, which are named as void closure and interdiffusion processes, were seen in fluorescence data. Transparency of the films was decreased with decreasing PS content, indicating that a phase separation process occurs between PS and BuA/MMA4 phases by thermal treatment, which results in turbid films. However, below R_c, no change was observed in I_P and I_tr upon annealing, whereas transparency increased overall with increasing BuA/MMA4 ratio. We explained this result as the phase separation process between PS and BuA/MMA4 blends. These results were also confirmed by AFM pictures. Film formation stages above R_c were modeled and related activation energies were calculated. POLYM. COMPOS., 27:431–442, 2006. © 2006 Society of Plastics Engineers     

Thermal and sonochemical degradation kinetics of poly(n‐butyl methacrylate‐co‐alkyl acrylates): Variation of chain strength and stability with copolymer composition

The thermal degradation of poly(n‐butyl methacrylate‐co‐alkyl acrylate) was compared with ultrasonic degradation. For this purpose, different compositions of poly (n‐butyl methacrylate‐co‐methyl acrylate) (PBMAMA) and a particular composition of poly(n‐butyl methacrylate‐co‐ethyl acrylate) (PBMAEA) and poly(n‐butyl methacrylate‐co‐butyl acrylate) (PBMABA) were synthesized and characterized. The thermal degradation of polymers shows that the poly(alkyl acrylates) degrade in a single stage by random chain scission and poly(n‐butyl methacrylate) degrades in two stages. The number of stages of thermal degradation of copolymers was same as the majority component of the copolymer. The activation energy corresponding to random chain scission increased and then decreased with an increase of n‐butyl methacrylate fraction in copolymer. The effect of methyl acrylate content, alkyl acrylate substituent, and solvents on the ultrasonic degradation of these copolymers was investigated. A continuous distribution kinetics model was used to determine the degradation rate coefficients. The degradation rate coefficient of PBMAMA varied nonlinearly with n‐butyl methacrylate content. The degradation of poly (n‐butyl methacrylate‐co‐alkyl acrylate) followed the order: PBMAMA < PBMAEA < PBMABA. The variation in the degradation rate constant with composition of the copolymer was discussed in relation to the competing effects of the stretching of the polymer in solution and the electron displacement in the main chain. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Effect of the monomer ratio on the properties of poly(methyl methacrylate butyl acrylate) latex‐modified mortars

This article deals with the effect of the monomer ratio on the typical properties of polymer‐modified mortars with poly(methyl methacrylate butyl acrylate) latices. Polymer‐modified mortars, with methyl methacrylate/butyl acrylate copolymer latices of various methyl methacrylate/butyl acrylate ratios, were prepared with different polymer/cement ratios and were tested for their workability, air content, compressive strength, flexural strength, and water absorption. On the basis of the test results, the effects of the monomer ratio and polymer/cement ratio on the typical properties were examined. The properties of the latex‐modified mortars were affected to a great extent by both the monomer ratio and polymer/cement ratio. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2403–2409, 2004     

Synthesis of poly(sodium acrylate‐co‐sodium 1‐(acryloyloxy) propan‐2‐yl phosphate) and comparative study on its swelling properties with poly(sodium acrylate) and poly(sodium acrylate‐co‐2‐hydroxypropyl acrylate)

A new superabsorbent copolymer, poly(sodium acrylate‐co‐sodium 1‐(acryloyloxy) propan‐2‐yl phosphate) [P(SA‐co‐SAPP)], was synthesized by a novel prepared monomer, 1‐(acryloyloxy) propan‐2‐yl phosphoryl dichloride. The swelling properties of the superabsorbent were investigated by comparison with poly(sodium acrylate) (PSA) and the copolymer of poly(sodium acrylate‐co‐2‐hydroxypropyl acrylate) [P(SA‐co‐HPA)]. The results showed that (1) the superabsorbent containing sodium 1‐(acryloyloxy) propan‐2‐yl phosphate had higher water absorbency at general testing conditions; (2) the swelling properties of P(SA‐co‐SAPP) and PSA were obviously influenced by pH of solutions, which were different from that of P(SA‐co‐HPA); (3) the swelling process and the saturated water absorbency of all superabsorbents were remarkably affected by cations, especially multivalent ones, while barely affected by anions. POLYM. ENG. SCI., 47:728–737, 2007. © 2007 Society of Plastics Engineers.     

Poly(styrene‐co‐butyl acrylate) latex‐reinforced polyester nonwoven fabric composites: Thermal and morphological studies

A series of thermoplastic composites were fabricated by impregnating the polyester nonwoven fabric in poly(styrene‐co‐butyl acrylate) latex having different monomer compositions of styrene and butyl acrylate viz., 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 weight by weight. Thermogravimetric analysis (TGA) of the composites was performed to establish the thermal stability and their mode of thermal degradation. From TGA thermograms, a slight improvement in thermal stability of the composites was noticed compared to polyester nonwoven fabric. Degradation kinetic parameters were obtained for the composites using Broido and Coats–Redfern methods. The activation energy (E_a) of the composites for the thermal degradation process lies in the range 7.1–261 and 60–264 kJ/mol for Broido and Coats–Redfern methods respectively. Morphology of the tensile‐fractured composites was studied using scanning electron microscopic technique. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009