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Cross‐linked cationic polyvinyl alcohol (CPVA) is obtained by solution polymerization using vinyl acetate (VAc) and N‐(isobutoxymethyl)acrylamide (IBMA) as main raw materials and free radical co‐polymerization using glycidyl methacrylate (GMA) and dimethylaminoethyl methacrylate (DM) as modified monomers. The structure is characterized by HNMR. The effects of DM monomer on the properties of CPVA are investigated. It turns out that CPVA dispersion is a Bingham fluid with good stability. The particle size of CPVA reaches minimum and the value is 147.2 nm, which is in favor of infiltration into the paper. It is more suitable for the DM dosage ranging from 2% to 2.5% in light of the mechanical properties of CPVA film. The obtained CPVA is amorphous and the degree of crystallinity is decreased. When used as surface sizing agent for paper, the water absorption of the sizing paper reaches minimum and the folding resistance reaches maximum when DM is 2.5%. The maximum dry and wet tensile indexes of the paper are increased by 190.71% and 331.09%, respectively. SEM results shows that the larger pores between the paper fibers are filled and cross‐linked after CPVA sizing, which is beneficial to the improvement of paper strength. [ABSTRACT FROM AUTHOR]

Objectives: To find a new appropriate evaluation for urethral plate quality in hypospadias repair, with particular interest in the width proportion of the urethral plate to the glans, serving as an appraisal index. Methods: Data were prospectively collected from prepubertal boys who underwent primary tubularized incised plate hypospadias repair between January 2014 and April 2016 in one center. Intrinsic parameters of the penis (meatal location, glans width, urethral plate width and curvature degree) were measured during the operation. Urethroplasty complications were recorded during follow up. The correlation between width proportion of the urethral plate to the glans and urethroplasty complications was analyzed. Results: Primary tubularized incised plate repair was carried out in 442 patients (mean age 2.8 years, range 0.5–12 years). At mean follow up of 26 months (range 12–38 months), urethroplasty complications occurred in 59 (13.3%) patients. The width proportion of the urethral plate to the glans was weakly correlated to both the glans width and meatal location. The width proportion of the urethral plate to the glans ranged from 0.18 to 0.73, with a mean of 0.39. The cut‐off value of width proportion of the urethral plate to the glans was determined to be 0.36 by the receiver operating characteristic curve. Urethroplasty complications occurred in 17 out of 254 patients (6.7%) with width proportion of the urethral plate to the glans >0.36, and 42 out of 188 patients (22.3%) with width proportion of the urethral plate to the glans ≤0.36. The width proportion of the urethral plate to the glans ≤0.36 showed an increased odds of 4.819‐fold (95% confidence interval 2.548–9.112, P < 0.001) risk of urethroplasty complications compared with width proportion of the urethral plate to the glans >0.36. Midshaft and proximal meatal location also increased the risk of urethroplasty complications. Conclusions: The present study highlights the value of the width proportion of the urethral plate to the glans for objectivity and accuracy in urethral plate evaluation, which in turn serves as an independent factor influencing outcomes in tubularized incised plate repair. [ABSTRACT FROM AUTHOR]

ABSTRACT Polyacrylamide copolymers (PAMVT) microspheres were prepared through inverse emulsion polymerization by using acrylic acid (AA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as functional monomers, N, N′-methylene bis-acrylamide (MBA) as crosslinker and modified vermiculite (MVMT) with the single-factor experiments. The initial and swelled particle sizes were tested through the dynamic light scattering (DLS). The swelled particle size under the optimum conditions could be 1.98 μm. The structure was characterized through Fourier transform infrared (FTIR), which indicated that vermiculite has successfully modified and the polymerization reaction was completed. The scanning electron microscopy (SEM) shows that MVMT was evenly filled with PAM copolymers. The water absorption capacity can be up to 80.2%. The recovery efficiency of the water flooding was increased from 69.33% to 77.56%. All these results indicated that the microspheres emulsions could be used as profile control agent to enhance the recovery efficiency. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44918. [ABSTRACT FROM AUTHOR]

ABSTRACT A series of cationic acrylic/alkyd resin (CPAAR) hybrid emulsions was successfully prepared through surfactant-free emulsion polymerization, using methacryloxyethyltrimethyl ammonium chloride, methyl methacrylate, butyl acrylate and alkyd resin as reaction monomers. And nonionic N-hydroxymethyl acrylamide (HAM) of different content was simultaneously incorporated into the CPAAR backbone. The structure of CPAAR copolymer was characterized by Fourier transform infared spectrometer, and then the effect of HAM content on properties of CPAAR emulsions was studied by particle size analyzer, transmission electron microscopy and rheometer. In addition, thermal properties, water absorption and contact angle of CPAAR latex films were also investigated. The results showed that the CPAAR emulsions prepared with 4.9 wt % HAM displayed smallest average particle size of 92.2 nm. As HAM content increased from 0 to 19.6 wt %, the initial viscosity of the emulsions increased from 22.48 to 53 mPa.s. At the same time, the emulsions transferred from Newtonian fluid to pseudoplastic fluid, and a transition from viscous liquid to elastic liquid was also detected. Meanwhile, the degradation temperature at 5% weight loss increased by 30.59°C. In addition, with increasing HAM content from 0 to 4.9 wt %, the water absorption and surface free energy of films increased by 4.42% and 5.02 mJ m−2, respectively. However, the water absorption and surface free energy kept almost invariable with further increase in HAM content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41406. [ABSTRACT FROM AUTHOR]

ABSTRACT UV curable waterborne polyurethane acrylate based on pentaerythritol triacrylate (PETA)/pentaerythritol tetraacrylate (PETTA) composite system was prepared by using polycaprolactone glycol (PCL), isophorone diisocyanate (IPDI), β-cyclodextrin (β-CD) and 2,2-dimethylol butanoic acid (DMBA) as the main materials. Besides, PETA was used as capping agent and PETTA was used as reactive diluent. By varying the additive amount of PETA and PETTA, a series of emulsions and films were obtained. The molecular structure was characterized by infrared spectra and a series of performance tests such as particle size, contact angle, tensile properties, UV curing performance, differential scanning calorimetry and thermogravimetric analysis were conducted. The result showed that more compact network structure was formed by introducing PETTA with higher reactivity into the polyurethane molecule under UV irradiation and many performances were improved as a whole. However, there existed phase separation to a certain extent. Especially when the content of PETTA was higher than 83.33%, the effect of compatibility became more prominent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41262. [ABSTRACT FROM AUTHOR]

ABSTRACT Crosslinking core-shell emulsions of waterborne fluorinated polyurethane-acrylate (WFPUA) were successfully synthesized using a solvent-free method. The crosslinkers of diacetone acrylamide and adipic dihydrazide were introduced into the WFPUA emulsions. The physical properties of hybrid emulsions such as the average particle size, stability, and viscosity were characterized. The core-shell of crosslinking WFPUA emulsion synthesized in this study was observed by transmission electron microscopy. Then, the results of Fourier transform infrared spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy indicated that the fluorinated monomer (FA) had been polymerized into the crosslinking waterborne polyurethane-acrylate polymer, and the fluorinated groups have evident enrichment on the film-air surface with the increase of FA content. At the same time, the thermal properties, water repellent/antifouling properties, and mechanical properties were measured. Moreover, the thermal properties and the elongation are raised but tensile stress and shore hardness are decreased with the increase of FA content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40970. [ABSTRACT FROM AUTHOR]

ABSTRACT A series of organic, solvent-free, epoxy-modified polyurethane-acryalte (EPUA) adhesives were prepared through in situ surfactant-free polymerization. Stable EPUA microemulsions with average particle diameters of less than 100 nm and a unimodal distribution were obtained through control of the epoxy content. Transitions from irregular shapes with a heterogeneous size distribution to a regular spherical particle morphology with an apparent core-shell morphology were obtained for EPUA with an increasing epoxy content to 8 wt %. With epoxy addition, EPUA displayed pseudoplastic behavior instead of Newtonian behavior, and increases in the viscosity and pseudoplastic behavior were detected. In addition, the EPUA emulsion transferred from a viscous liquid to a solidlike liquid. The addition of epoxy was beneficial for phase mixing, interaction, and entanglements between polyurethane and polyacrylate, and the interactions between the EPUA colloidal particles were also enhanced. The thermal stability, mechanical properties, and water and solvent resistance were thereby improved, as was the cohesive properties. However, the corresponding properties were weakened with excessive epoxy, and this was ascribed to the greatly increased particle size, viscosity, and phase separation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39886. [ABSTRACT FROM AUTHOR]

ABSTRACT Aqueous acetic acid lignin containing polyurethane (ALPU) surfactants were prepared by the replacement of some hydrophobic poly(caprolactone diol) with different concentrations of multifunctional acetic acid lignin (AL), and with dimethylol propionic acid as the hydrophilic segment. The infrared spectra, together with thermogravimetric analysis, demonstrated the presence of AL in the polyurethane (PU) chains. In addition, the effects of the AL concentration on the particle size, morphology, rheological behavior, and surface activity of the dispersions were investigated. The ALPU particles displayed a spherical morphology. With increasing AL concentration from 0 to 10 wt %, the particle size increased from 36 to 260 nm, and the unimodal distribution was detected for ALPU10 with a 10 wt % AL addition. The viscosity and shear-thinning behavior of the ALPU dispersions decreased, and the lowest surface tension and critical micelle concentration (cmc) were detected for ALPU10. However, when the AL concentration was 15 wt % (ALPU15), the surface tension and cmc increased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1855-1862, 2013 [ABSTRACT FROM AUTHOR]