Polyacrylate Content Research Articles

Synthesis of a novel biodegradable curing agent modified by castor oil for polyacrylate adhesive applications

AbstractA novel functional carbamate oligomer with high curing activity was prepared by addition polymerization using diisocyanate and castor oil (CO) and used as curing agent for polyacrylate adhesive. The influence factors of such modified castor oil (mCO) preparation, including monomer type, NCO/OH group mole ratio, reaction temperature and time, were explored. When the CO was reacted with hexamethylene diisocyanate among the NCO/OH group mole ratio of 0.56–0.75 at 75°C for 4 h, the NCO value of mCO could be in the range between 0.10 and 0.20 mmol/g. At this point, the peel adhesion and the tack of the adhesive with mCO in the mass ratio of 1/1 can be above 2.3 N/cm and 23#, respectively. In addition, the influence of rosin resin content, polyacrylate content, and the active equivalent of mCO on the properties of adhesive tape was studied in detail. When the pressure sensitive adhesive is prepared by 50% polyacrylate, 25% mCO and 25% rosin resin, the peel adhesion and the tack can reach 4.63 N/cm and 23#. The relative biodegradation rate of cured adhesive with 25% of mCO and 25% of rosin resin is 47.56% after 45 days, with an increase of 80.95% compared to that of pure adhesive. The highly biodegradable mCO endows the adhesive tape with better mechanical property and biodegradability, thus making it a promising adhesive tape for packing applications.

Preparation of polyacrylate/nanoemulsion composites and their adjuvant activity with OVA as the model antigen

A series of polyacrylate/nanoemulsion composites were prepared to form a new kind of nanoemulsion, their particle sizes and polydispersity indices were measured. The particle sizes of the polyacrylate/nanoemulsion composites are consistent with nanoemulsions used in the system. In addition, an ELISA-specific antigen-antibody binding method was used for physical adsorption experiments on ovalbumin. Results showed that the adsorption performance of the polyacrylate/nanoemulsion system is best when the particle size was 55 nm, and the nanoemulsion content was 20 wt%, 30 wt%, or 40 wt%. Meanwhile, in order to select the optimum experimental conditions, in vivo immunity experiments in mice were carried out to analyze the adjuvant properties of ovalbumin as a model antigen. Analysis of ovalbumin-specific IgG, IgG1, and IgG2a antibody titers showed the best results when the particle size of the polyacrylate/nanoemulsion composites is 55 nm, the polyacrylate content is 0.5 wt%, and the nanoemulsion contents is 20 wt%. Meanwhile, titer analysis also showed that the polyacrylate obviously enhanced the IgG2a titer in mice. Our polyacrylate/nanoemulsion composites can both stimulate humoral and cellular immunity and have an enhanced adjuvant effect on water-soluble protein antigens.

High-strength porous alumina ceramics prepared from stable wet foams

Porous ceramics have been widely used in heat insulation, filtration, and as a catalyst carrier. Ceramics with high porosity and high strength are desired; however, this high porosity commonly results in low strength materials. In this study, porous alumina with high porosity and high strength was prepared by a popular direct foaming method based on particle-stabilized wet foam that used ammonium polyacrylate (PAA) and dodecyl trimethyl ammonium chloride (DTAC) as the dispersant and hydrophobic modifier, respectively. The effects of the dispersant and surfactant contents on the rheological properties of alumina slurries, stability of wet foams, and microstructure and mechanical properties of sintered ceramics were investigated. The microstructure of porous ceramics was regulated using wet foams to achieve high strength. For a given PAA content, the wet foams exhibited increasing stability with increasing DTAC content. The most stable wet foam was successfully obtained with 0.40 wt% PAA and 0.02 wt% DTAC. The corresponding porous alumina ceramics had a porosity of 82%, an average grain size of 0.7 µm, and a compressive strength of 39 MPa. However, for a given DTAC content, the wet foams had decreasing stability with increasing PAA content. A possible mechanism to explain these results is analyzed.

Facile preparation of homogenous waterborne poly(urethane/acrylate) composites and the correlation between microstructure and improved properties

AbstractHomogenous waterborne polyurethane/polyacrylate emulsions were synthesized based on the prepared polyurethane and polyacrylate through a facile process. The attention was attracted to the miscibility and performance of waterborne polyurethane and polyacrylate. The structures and properties of waterborne polyurethane and waterborne polyurethane/polyacrylate samples were characterized by using Fourier transform infrared spectroscopy, transmission electron microscope, X‐ray photoelectron spectroscopy, X‐ray diffractometer, thermogravimetric, and so forth, as well as solid content and tensile testing. The results showed that the micro morphology of waterborne polyurethane/polyacrylate emulsion presented single‐phase structure with the stoichiometric polyacrylate content increasing from 33% to 80% to waterborne polyurethane. The waterborne polyurethane/polyacrylate films surface is rich in polyacrylate phase. Meanwhile, waterborne polyurethane/polyacrylate composites showed significant improvement in thermal stability and elongation at break, smaller particle size and narrower particle size distribution comparing with waterborne polyurethane.

Effect of using ink containing polyacrylate and silicone surfactant on the inkjet printing of quantum dot films

ABSTRACTFor device printing, it is important for uniform films to be printed because the morphology of the film affects the performance of the device in inkjet printing. In this study, to prepare stable and well-dispersed ink, polyacrylate and silicone surfactant BD-3033H were added to ink. Then a uniform quantum dot (QD) film was obtained by optimizing the polyacrylate and silicone surfactant contents of the ink as well as the substrate temperature. The change of the polyacrylate structure from a curly chain structure to a three-dimensional network structure blocked the outward flow of QDs. Silicone surfactant BD-3033H caused Marangoni flow and made the QDs flow inward. When the substrate temperature was increased, the solvent evaporation rate was accelerated, the contact line was pinned, and the outward flow was enhanced, which changed the film structure from convex to flat. Finally, when the polyacrylate content was 12 wt%, the silicone surfactant BD-3033H content was 0.10 wt%, the substrate temperature was 40°C, and the coffee ring effect was eliminated. A uniform QD film was printed, providing a technical guarantee for the fabrication of QD devices in the future.

Performance analysis and experimental study on rainfall water purification with an extensive green roof matrix layer in Shanghai, China.

Current research has validated the purification of rainwater by a substrate layer of green roofs to some extent, though the effects of the substrate layer on rainwater purification have not been adequately quantified. The present study set up nine extensive green roof experiment combinations based on the current conditions of precipitation characteristics observed in Shanghai, China. Different rain with pollutants were simulated, and the orthogonal design L9 (33) test was conducted to measure purification performance. The purification influences of the extensive green roof substrate layer were quantitatively analyzed in Shanghai to optimize the thickness, proportion of substrate, and sodium polyacrylate content. The experimental outcomes resulted in ammonium nitrogen (NH4+-N), lead (Pb), and zinc (Zn) removal of up to 93.87%, 98.81%, and 94.55% in the artificial rainfall, respectively, and NH4+-N, Pb, and Zn event mean concentration (EMC) was depressed to 0.263 mg/L, 0.002 mg/L and 0.018 mg/L, respectively, which were all well below the pollutant concentrations of artificial rainfall. With reference to the rainfall chemical characteristics of Shanghai, a combination of a 200 mm thickness, proportions of 1:1:2 of Loam: Perlite: Cocopeat and 2 g/L sodium polyacrylate content was suggested for the design of an extensive green roof substrate to purify NH4+-N, Pb and Zn.

Preparation and properties of poly (propylene carbonate)-based waterborne polyurethane-acrylate composite emulsion

Waterborne polyurethane-acrylate (WPUA) composite emulsion based on waterborne polyurethane (WPU) was prepared by sequential polymerization with methyl methacrylate (MMA) and butyl acrylate (BA). WPU was synthesized to form seed emulsion dispersion using poly (propylene carbonate) (PPC) diol as soft segment. Polyacrylate (PA) content and MMA/BA mass ratio were varied to investigate the influence on performance properties. The emulsions were characterized by evaluating the particle size, stability, and appearance. The WPUA films were characterized by FT-IR and TGA. The tensile properties, hardness, surface hydrophilicity, and coating adhesion of film were also tested. The incorporation of PA in PPC-based WPU improved the adhesion, pencil hardness, water resistance, and hydrophilicity. With the increase of PA content, the tensile strength increased initially and then decreased, while the elongation at break and toughness decreased. The experimental results indicated good compatibility and synergistic effect between PPC-based WPU and PA, which resulted in a remarkable improvement in thermal properties, adhesion, and pencil hardness.

Effect of Acrylic Content on the Properties of the Polyurethane/Polyacrylate Composite Emulsion

A polyurethane/polyacrylate (PUA) composite emulsion was synthesized by using polyurethane (PU) as seeds with soap-free emulsion polymerization, in which methyl methacrylate (MMA) and butyl acrylate (BA) were used as main acrylic monomers. The effect of acrylic contents and “stiff” and “soft” weight ratio of acrylic monomers on the properties of the films were investigated. The Fourier transform infrared (FTIR) results showed that acrylic monomers were involved in the emulsion copolymerization. The optimum composition of PUA composite formation was obtained when the polyacrylate (PA) content was 20%, in which the weight ratio of MMA and BA was 2/1. With the increment of PA content, the decomposition temperature increased.

Aqueous PUA emulsion prepared by dispersing polyurethane prepolymer in polyacrylate emulsion

ABSTRACTWaterborne polyurethane/polyacrylate (PUA) emulsions were prepared by dispersing polyurethane (PU) prepolymer in polyacrylate (PA) emulsion; therefore, the PU particles formed in the presence of PA nanoparticles. The particle size and its distribution of the composite PUA emulsion were determined by dynamic light scattering. The result shows that the average particle size increases initially and then decreases with increasing PA content, which is confirmed by transmission electron microscope characterization. The surface properties of PUA films were analyzed by water contact angle and atomic force microscope topography. It indicates that the water contact angle and the average roughness of the composite PUA films are larger than those of the PU film. Meanwhile, mechanical properties test, scanning electron microscopy, and thermogravimetric analyses disclose that the PUA films are characterized by enhanced tensile strength, rough fractured surface, and good thermal stability. The preparation method proposed in this article is an effective and convenient way to manufacture composite PUA emulsion. The composite PUA emulsion can be potentially used in coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43203.

Phase behaviour and morphology of composite comprising of poly(ethylene oxide), polyacrylate and lithium perchlorate

Thin films of poly(ethylene oxide) (PEO) and polyacrylate (PAc) blend and the composite PEO/PAc/lithium perchlorate (LiClO4) are prepared via solution casting method. Thermal analysis using differential scanning calorimetry depicts that both the PEO/PAc blend and the PEO/PAc/LiClO4 composite form single phase systems, as evident from the presence of single composition-dependant glass transition temperature (Tg). Polarized optical microscopy (POM) was applied to study the spherulite growth rate and morphology of PEO in both the PEO/PAc blend and PEO/PAc/LiClO4 composite. Homogeneity in the phase behaviour of the PEO/PAc blend and the PEO/PAc/LiClO4 composite is reaffirmed by the continuous suppression of the growth rate and the severe deformation and coarseness of the PEO spherulite with ascending PAc content in the blend and increasing LiClO4 concentration in the composite. Additionally, the amount of salt that causes macro-phase separation in the neat polymers and the PEO/PAc blends is governed by the coordination ability of the polymer, especially PEO, to the Li+ ion. Results from both thermal analysis and POM reflect the higher preference of LiClO4 for PEO than PAc. Therefore, PEO/PAc 85/15 blend is observed to exhibit the highest capability to interact with the Li+ ion.

Synthesis and characterization of self-crosslinked polyurethane/polyacrylate composite emulsion based on carbonyl–hydrazide reaction

Self-crosslinkable aqueous polyurethane (PU)/polyacrylate (PA) composite emulsion was obtained by radical copolymerization. Fourier transform infrared spectroscopy (FT-IR) result shows that the cross-linking reaction between the carbonyl group and the hydrazine group has happened. The influence of the hydrazide-carbonyl molar ratio and the PA content on the properties of the composite emulsions and their films were investigated. The results show that, under the optimal hydrazide-carbonyl molar ratio (n (hydrazine group)/n (carbonyl group) =1:1), the water absorption is 10.56 %, and the mechanical properties and thermal stabilities are both improved. As the PA content increases from 0 wt% to 15 wt%, the tensile strength increases from 5.7 MPa to 7.3 MPa and the gel content increases from 70.3 % to 87 %.

Synthesis and characterization of sulfonated polyol-based waterborne polyurethane-polyacrylate hybrid emulsions

Polyurethane (PU) dispersion was prepared with sulfonate groups to make the PU dispersible. Then, polyurethane-polyacrylate (PU-PA) hybrid emulsions were synthesized by seeded emulsifier-free emulsion polymerization with the previously synthesized PU dispersion as a source of seed particles. In the results of the particle-size distribution of the PU-PA hybrid emulsions, the average particle size of the hybrid emulsions increased from 1.2 to 9.1 μm when the polyacrylate content was increased from 0.2 to 1.0 by weight. In addition, the scanning electron microscopy results showed that the size of the polyacrylate latex particles was increased with increases in polyacrylate content. This result suggests that the hydrophobic polyacrylate can easily diffuse into PU particles, where the free radical chain-growth polymerization takes place. In the thermal analysis results, shifts in T g,1 and T g,2 were observed, which are related to the partial compatibility and inter-diffusion of the PU dispersion and PA components. The TGA curves shifted to a higher temperature with increases in polyacrylate content, which indicates a higher thermal stability of the PU-PA hybrid emulsion films. The PU-PA hybrid emulsion films showed improvement in the thermal stability and mechanical properties when compared with the pure polyurethane film, due to the increase in the formation of strong interaction between the PU and PA molecules. Open image in new window

EFFECT OF FLUORINATED POLYACRYLATE CONTENT ON THE GRADIENT STRUCTURE AND SURFACE PROPERTY OF FLUORINATED/NON-FLUORINATED POLYACRYLATE LATEX BLEND FILMS

In order to obtain the gradient fluorinated/non-fluorinated polyacrylate latex blend films as cheap as possible,the fluorinated polyacrylate emulsion with small particle size was synthesized by bulk emulsion polymerization method,the acrylate copolymer emulsion with big particle size was synthesized by semicontinuous emulsion polymerization method,and then the fluorinated polyacrylate emulsion and the acrylate copolymer emulsion were mixed with a series of ratios(1/9,2/8,3/7,4/6,5/5).The blend latices were dried on clean glass at 20℃ and then annealled at 110℃/210℃ for some time(2~6 h).The effects of the fluorinated polyacrylate content on the gradient structure and surface property of the blend films were discussed.The content of fluorine on the film surface and the film section was analyzed by XPS,SEM-EDX.The surface properties and morphology were characterized by contact angle measurements and AFM.It was found that,while the content of fluorinated polyacrylate latex in the blend system was up to 30 wt%,the small and hard fluorinated polyacrylate particles were selectively gathered on the film-air interface after film-formation at room temperature,and the fluorine content increased from the film-glass interface to the film-air interface gradually in the blend films annealled 2 h at 110℃.The obtained gradient film has low surface free energy as the pure fluorinated polyacrylate and strong adhesion as the pure polyacrylate.The further increasing of fluorinated polyacrylate in the blend system helped the formation and enlargement of gradient structure,but the adhesion of film was decreased a little.The emulsion system with the content of fluorinated polyacrylate latex under 30 wt% was hard to form gradient structure.

Thermal properties and surface energy characteristics of interpenetrating polyacrylate and polybenzoxazine networks

We have prepared semi-interpenetrating polyacrylate networks (PA/BA-m s-IPNs) through rapid photopolymerization of a triacrylate monomer (TMPTA) in the presence of a photoinitiator (I184), a tetramercaptane transfer agent (4SH), and N-methyl-bisbenzoxazine (BA-m). Next, we prepared novel fully interpenetrating polyacrylate (PA) and polybenzoxazine (PBZ) networks (PA/PBZ f-IPNs) through thermal polymerization of the BA-m monomer at 180°C for 4h. For the PA/BA-m s-IPNs, the BA-m monomers can be frozen and dispersed in the UV-cured PA network within 5min to inhibit macrophase separation. After thermal polymerization, the phenol units of the ring-opened PBZ segments can form a hydrogen-bonding interface with the carbonyl groups to improve the compatibility between the PBZ microdomains and the PA networks. From an analysis using Kissinger's method, the non-isothermal kinetics of the thermal polymerization for the PA/BA-m s-IPNs indicate that an increase in the PA content increased the steric hindrance of PBZ polymerization. We used DSC, TGA, and contact angle analyses to determine the glass transition temperature, thermal stability, and surface free energy, respectively, of the PA/PBZ f-IPNs. The thermal stability and surface free energy of these PA/PBZ f-IPNs display linear relationships with respect to the PBZ content.

Structure and properties of polyurethane/polyacrylate latex interpenetrating networks hybrid emulsions

Some new kinds of novel polyurethane (PU)/polyacrylate (PA) latex interpenetrating networks (LIPNs) were synthesized. Firstly PU dispersions were synthesized by self-emulsification polymerization. Then PU/PA LIPNs using PU dispersion as the seed were prepared by soap free emulsion polymerization. The effects of different PU/PA ratios, the blending method and the NCO/OH molar ratio of PU components on PU/PA LIPNs performance were also investigated. The structure and properties of PU/PA LIPNs such as mechanical properties, particle size, morphology of the surface were characterized by dynamic mechanical analysis, scanning electron microscopy, and dynamic light scattering. It was found that PU/PA LIPNs can markedly improve the water resistance and the mechanical properties of PU latex much more than those of PU/PA physical blends due to a great deal of interpenetrating and entangling between PU and PA latex. Moreover, the particle size of PU/PA LIPNs is related to the PA content and NCO/OH molar ratio of PU components: the higher the NCO/OH molar ratio in PU dispersions, the larger is the particle size of PU/PA LIPNs, and the average particle size of PU/PA LIPNs becomes larger with an increase in PA content.

Adsorption of Some Antitumour Compounds on Polymer Adsorbents

The adsorption of farmorubicine, methotrexate and 5-fluorouracil on adsorbents based on polyethylene grafted with polyacrylic acid (polyacrylate content Δp of 4, 15 and 80%) and polyacrylamide (polyacrylamide content Δp of 14%) has been investigated. A comparative estimation of the sorptive activity of the investigated adsorbents with respect to different antitumour compounds has been carried out. The influence of NaCl addition on the parameters of the kinetics and equilibrium adsorption of farmorubicine and methotrexate has been established.

Effect of Polymer Charge Density on the Phase Behavior of Sodium Poly(acrylate-co-acrylamide)−DTAB Systems

The phase behavior of a series of sodium poly(acrylate-co-acrylamide)−dodecyltrimethylammonium bromide (DTAB)−water systems has been investigated. The polyacrylate content in the copolymer (and hence the ionic group content) was varied from 16 to 80%. Both binodals and spinodals in the ternary aqueous systems were determined at 25 °C, spinodals for the 80, 40, 30, and 16% acrylate content polymer−DTAB systems, and binodals for the 80, 40, and 30% acrylate content polymers. Phase separation is found to be associative in all systems; ie., the binodal curves are the result of phase equilibrium tie-lines in which a concentrated polymer−surfactant gel is in equilibrium with a dilute supernatant. The two-phase equilibrium area in the phase diagram decreases with decreasing ionic content of the polymer. Experimental results for the spinodals are compared to calculate spinodals and plait points using a Flory−Huggins type interaction model with surfactant micelles as the second polymer component. Using reasonable ...

Grafting of 2‐hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers

AbstractGrafting of 2‐hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers, initiated by the bisulfite/pesulfate redox system, has been investigated. Using the method of statistical planning of experiments, regression equations have been obtained describing the effects of the monomers concentration and the composition of the initiating system on the monomers conversion, degree of grafting and on physical properties of grafted collagen. The relationship between the polyacrylate content in the composites prepared and their swelling ability, water absorption capacity, and the tensile strength is discussed.

The water absorbency of hydrolyzed polyacrylonitrile‐grafted cellulose fibers

AbstractThe water absorbency of a bleached softwood kraft pulp, as measured by its water retention value (WRV), was increased up to 30 times by graft polymerizing polyacrylonitrile (PAN) and subsequently hydrolyzing it to sodium polyacrylate–polyacrylamide copolymer. WRV was found to be related to the initial PAN graft level rather than to the final sodium polyacrylate content, and was independent of the grafting process used. However, the ceric ion process was found superior to both the cellulose xanthate–H2O2 and ferrous ion–H2O2 redox systems in that it occasioned only a minor loss during the hydrolysis stage and the WRV was less affected by drying. The WRV remained constant as pH was lowered from 9 to 5 but dropped to the level of unmodified pulp at pH 3.5 where the sodium salt is fully converted to poly(acrylic acid). Retention of 1% aqueous NaCl was about 60% of the WRV. The swelling properties of the grafted fibers under various conditions appear to be explained by considering the grafting to act in two ways: (a) the introduction of a potentially hydrophilic component capable of generating swelling pressures and (b) the reduction in the cohesion of the fiber by the interposition of graft polymer chains in the fiber structure.