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Acrylic waterproofing materials are known for their excellent physical properties, waterproofing capabilities, and convenient construction, but their high cost and under-researched bonding strength pose challenges. To enhance adhesion and elucidate the imperviousness mechanism of engineering waterproofing materials while effectively controlling costs, this study proposed the compounding of acrylic ester polymer emulsion with low-cost styrene-acrylate copolymer emulsion for the preparation of waterproofing materials. By integrating theoretical analysis with experimental research, the physical and mechanical properties, as well as the imperviousness of the waterproofing materials, were investigated. The optimal mix-ratio design for the waterproofing materials was determined. Results demonstrate that, (1) The compounding of styrene-acrylic emulsion with pure-acrylic emulsion can achieve good performance while lowering costs. (2) The common silicate cement strength 42.5MPa (C42.5) had better comprehensive properties than the common silicate cements strength 32.5MPa (C32.5) and 52.5MPa (C52.5) and the rapid-hardening sulfate-aluminate cement. (3) In the imperviousness and bonding-strength tests of the coating, when the waterborne non-silicone defoamer was added at 0.3%, it was dense inside the coating with reduced microspaces, and the coating passed the imperviousness test after 30 min under a water pressure of 0.3 MPa. (4) The bonding strength with cement-based surfaces was 1.8 MPa. This study can serve as a good reference for research on high-bonding waterproofing coatings of acrylic acid for underground engineering applications and imperviousness-performance tests. [ABSTRACT FROM AUTHOR]

The exchange of small molecules between the cell and the environment happens through transporter proteins. Besides nutrients and native metabolic products, xenobiotic molecules are also transported, however it is not well understood which transporters are involved. In this study, by combining exometabolome screening in yeast with transporter characterization in Xenopus oocytes, we mapped the activity of 30 yeast transporters toward six small non-toxic substrates. Firstly, using LC--MS, we determined 385 compounds from a chemical library that were imported and exported by S. cerevisiae. Of the 385 compounds transported by yeast, we selected six compounds (viz. sn-glycero-3-phosphocholine, 2,5-furandicarboxylic acid, 2-methylpyrazine, cefadroxil, acrylic acid, 2-benzoxazolol) for characterization against 30 S. cerevisiae xenobiotic transport proteins expressed in Xenopus oocytes. The compounds were selected to represent a diverse set of chemicals with a broad interest in applied microbiology. Twenty transporters showed activity toward one or more of the compounds. The tested transporter proteins were mostly promiscuous in equilibrative transport (i.e., facilitated diffusion). The compounds 2,5-furandicarboxylic acid, 2-methylpyrazine, cefadroxil, and sn-glycero-3- phosphocholine were transported equilibratively by transporters that could transport up to three of the compounds. In contrast, the compounds acrylic acid and 2-benzoxazolol, were strictly transported by dedicated transporters. The prevalence of promiscuous equilibrative transporters of non-native substrates has significant implications for strain development in biotechnology and offers an explanation as to why transporter engineering has been a challenge in metabolic engineering. The method described here can be generally applied to study the transport of other small non-toxic molecules. The yeast transporter library is available at AddGene (ID 79999). [ABSTRACT FROM AUTHOR]

The 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers are mimetic to phospholipids, being widely used as biocompatible polymers. In our previous study, MPC polymer hydrogels proved more effective for optical tissue clearing compared to acrylamide (AAm) polymer hydrogels. In the present study, 2-acryloyloxyethyl phosphorylcholine (APC) was synthesized and employed to create hydrogels for a comparative analysis with methacrylic MPC-based hydrogels. APC, an acrylic monomer, was copolymerized with AAm in a similar reactivity. In contrast, MPC, as a methacrylic monomer, demonstrated higher copolymerization reactivity than AAm, leading to a spontaneously delayed two-step polymerization behavior. This suggests that the polymer sequences and network structures became heterogeneous when both methacrylic and acrylic monomers, as well as crosslinkers, were present in the copolymerization system. The molecular weight of the APC polymers was considerably smaller than that of the MPC polymers due to the formation of mid-chain radicals and subsequent β-scission during polymerization. The swelling ratios in water and strain sweep profiles of hydrogels prepared using acrylic and methacrylic compounds differed from those of hydrogels prepared using only acrylic compounds. This implies that copolymerization reactivity influences the polymer network structures and crosslinking density in addition to the copolymer composition. APC-based hydrogels are effective for the optical clearing of tumor tissues and are applicable to both passive and electrophoretic methods. [ABSTRACT FROM AUTHOR]

This article discusses a case of occupational allergic contact dermatitis in a 34-year-old woman who worked as a casino dealer for 10 years. The woman presented with a progressive dermatitis on both hands, which worsened during work. Patch testing revealed a strong positive reaction to triethylene glycol diacrylate and the blackjack card she handled at work. The blackjack card contained tripropylene glycol diacrylate, which was identified as the cause of the dermatitis. The article highlights the unusual presentation of occupational allergic contact dermatitis caused by acrylates in playing cards. [Extracted from the article]

Compared with room temperature, the responsive curve of polymer humidity sensor usually presents a nonlinear shift and distortion at higher temperature conditions, this will sharply decrease the accuracy and working stability of polymer humidity sensor. In this paper, an organic–inorganic cross‐linked interpenetrating network (c‐IPN) between silocane compounds and acrylic prepolymer resin has been constructed to prepare a c‐IPN humidity‐sensitive material by in‐situ crosslinking reaction. The results shows that the prepared c‐IPN polymer humidity sensor shows more sensitive in range of 30–90% RH, with higher linearity coefficient of 0.9996 and lower hysteresis coefficient of 1.25% RH. And the c‐IPN polymer humidity sensor exhibits more higher stability at higher temperature than that at room temperature. Meanwhile, the temperature coefficient of the c‐IPN polymer humidity sensor can decrease to 0.53% RH/°C, along with temperature hysteresis curve linear coefficient increase to (R2 = −0.999), when (3‐aminopropyl) triethoxysilane is used at dosage of 10 wt.% druing crosslinking reaction. This study presents a feasible practical technical solution for developing novel high‐performance polymer humidity‐sensitive materials and its humidity sensors at wider temperature range. [ABSTRACT FROM AUTHOR]

The compatibility of polyorganylsiloxanes and high-molecular polymers used as emulsifiers was evaluated. The surface and bulk properties of the studied compounds were evaluated using the solubility parameters (6). It is shown that the copolymers of acrylic acid compound - polyacrylamide and hydrolyzed polyacrylamide, as well as polyvinyl alcohol without residual acetate groups in the macromolecule have the highest degree of incompatibility with polyorganylsiloxanes. It was established that the presence of residual acetate groups in the macromolecule of polyvinyl alcohol leads to an increase in the degree of compatibility of polymers. The calculated data on the fractions of solubility parameters and cohesive energy of polyorganylsiloxanes and emulsifying polymers are presented. The contributions of the components of polymers cohesive energy due to the fractions of dispersion interaction cw, dipole-dipole interaction add, and hydrogen bonding ah, as well as their influence on the degree of solubility of the polymer - emulsifier system, are shown. The choice of polyvinyl alcohol with residual acetate groups as an emulsifier for polyorganylsiloxanes is theoretically substantiated based on the concept of the solubility parameter as a measure of the affinity of the system components. The developed approach to assessing the compatibility of the polymer - emulsifier system is of practical importance for the creation of polymer compositions in the finishing works. [ABSTRACT FROM AUTHOR]

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Purpose: Acrylic resin teeth on fixed implant prostheses are subject to time-dependent wear. The purpose of this retrospective analysis is to evaluate and describe the management of such wear in the context of selected variables--patient gender and age, dental arch location, and opposing dentition. The clinical and dental laboratory process to replace the worn teeth is defined as a retread.Materials and Methods: A retrospective database review from a single private prosthodontic practice was carried out on all patients who had undergone a retread procedure. The patient pool included 205 arches in 194 patients (70 in men, 135 in women) with a mean age of 57.4 years (range: 19.9 to 80.5 years). The retread procedure is described.Results: The mean time between final prosthesis delivery and retread was 7.8 years (range: 1.1 to 22.9 years). Statistical analysis was significant according to dental arch and opposing dentition. A statistical difference was also noted in patients undergoing multiple retread procedures, with a reduction in time between the subsequent procedures.Conclusion: Acrylic resin components of implant-supported hybrid prostheses wear over time and are influenced by a combination of the nature of the opposing dentition and patient habits. The dental laboratory process to retread the implant-supported framework is important for long-term patient care and maintenance of an appropriate vertical dimension of occlusion. [ABSTRACT FROM AUTHOR]

The widespread UbiD enzyme family utilises the prFMN cofactor to achieve reversible decarboxylation of acrylic and (hetero)aromatic compounds. The reaction with acrylic compounds based on reversible 1,3-dipolar cycloaddition between substrate and prFMN occurs within the confines of the active site. In contrast, during aromatic acid decarboxylation, substantial rearrangement of the substrate aromatic moiety associated with covalent catalysis presents a molecular dynamic challenge. Here we determine the crystal structures of the multi-subunit vanillic acid decarboxylase VdcCD. We demonstrate that the small VdcD subunit acts as an allosteric activator of the UbiD-like VdcC. Comparison of distinct VdcCD structures reveals domain motion of the prFMN-binding domain directly affects active site architecture. Docking of substrate and prFMN-adduct species reveals active site reorganisation coupled to domain motion supports rearrangement of the substrate aromatic moiety. Together with kinetic solvent viscosity effects, this establishes prFMN covalent catalysis of aromatic (de)carboxylation is afforded by UbiD dynamics. Understanding the structure and dynamics of enzymes is important for a number of applications. Here, the authors report on the crystal structure of vanillic acid decarboxylase, and show how the dynamics of the UbiD superfamily enzymes relate to the covalent catalysis of aromatic (de)carboxylation. [ABSTRACT FROM AUTHOR]

Poly(L-lactic acid) (PLLA) blends with excellent low-temperature toughness and strength were prepared by melt compounding with acrylic ester based impact resistance agent (AEIR). The morphology, thermal properties, mechanical properties and biodegradability of the blends were investigated. Morphology observations revealed the blend was immiscible but had good compatibility with the dispersed phase size of about 200–300 nm. With the addition of AEIR, dramatic improvement in toughness of PLLA was achieved in a wide temperature range, especially at low temperatures the tensile strength was effectively remained. For the blend with 20 wt% AEIR, the tensile strength, elongation at break and impact strength were 51.6 MPa, 72% and 77.1 KJ/m2 at −20 °C, respectively, much greater than that reported. The calculated T g of AEIR was lower than the test temperatures, and the brittle-tough transition occurred. The PLLA matrix demonstrated obvious shear yielding which induced energy dissipation and therefore lead to excellent toughness of the blends. Moreover, the biodegradation of PLLA was enhanced after blends preparation. [ABSTRACT FROM AUTHOR]

Background: Contact allergy from acrylic compounds is a "hot topic". Knowledge on the exact chemical composition of acrylic products is superficial. Aims: To retrospectively describe patients with allergic reactions to acrylic compounds. Methods: We included patients who had been tested with acrylate patch test series and displayed allergic reactions to at least one acrylic compound. Chemical analyses were often performed when safety data sheets of implicated products failed to reveal acrylic compounds to which the patient tested positive. Results: In 2010–2019 a total of 55 patients met the inclusion criteria. Eight cases of allergic contact dermatitis were due to anaerobic sealants, seven to dental products, three to windscreen glues, seven to eyelash glues and/or nail products in the beauty sector, three to UV‐cured printing inks, two to paints/lacquers, and one to polyester resin system. The origin of these contact allergies was occupational with the exception of four beauty sector workers who had developed eyelid symptoms from eyelash extensions glued onto their own eyelashes. We invariably detected methacrylate monomers in 15 chemical analyses of 12 different anaerobic sealants. Conclusions: Safety data sheets of anaerobic sealants often lack warnings for skin sensitization, although these products regularly contain sensitizing methacrylates. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the difference in cytotoxicity of soft denture lining materials depending on their component types. Materials and Methods: Ten commercially available soft denture lining materials (SDLM) consisting of five silicone-based materials and five acrylic-based materials were evaluated. For the MTT test, cured SDLM samples were extracted in a culture medium for 24 hours, and L-929 cells were incubated in the extracted medium for 24 hours. Cell viability was determined using a microplate reader and compared with those of the negative control, which were cultured in a culture medium without test material. Agar overlay test was performed for the cured SDLM samples according to International Organization for Standardization (ISO) 7405. Results: Among silicone-based lining materials, GC Reline Soft, Mollosil plus, and Dentusil showed a cell viability of 107.2% ± 4.5%, 102.3% ± 2.84%, and 93.0% ± 8.0%, respectively, compared with the control. Mucopren and Sofreliner Tough displayed significantly lower cell viability (86.4% ± 10.3% and 81.5% ± 4.3%, respectively) compared with the control (P < .05). Among acrylic-based materials, Kooliner, Visco-gel, Soft liner, Dura Base, and Coe-Soft displayed cell viability of 99.2% ± 14.6%, 93.1% ± 9.5%, 89.1% ± 9.8%, 87.6% ± 7.9%, and 75.9% ± 15.7%, respectively, compared with the control. Dura Base and Coe-Soft displayed significantly lower cell viability compared to the control. However, for all tested materials, cell viability exceeded the requirement limit of 70% specified in ISO 10993-5. In the agar overlay test, all five silicone-based materials and acrylic-based Kooliner were ranked as “noncytotoxic.” However, Visco-gel was ranked as “mildly cytotoxic,” and Soft liner, Coe-Soft, and Dura Base were ranked as “moderately cytotoxic.” Conclusion: When an acrylic-based soft denture lining material is used, the possibility of a cytotoxic effect should be considered. [ABSTRACT FROM AUTHOR]

Ammonia is the most essential hydrogenated nitrogen composition that can cause problems when it enters the environment. One of the most important natural and synthetic adsorbents is hydrogels, which can reduce the economic costs of treating industrial effluents and minimize the concentration of ammonia in the drainage of sugarcane fields. In this study, carrageenan, which is a type of polysaccharide, and acrylic acid were used to prepare nanomagnetic hydrogels. Also, the effect of pH, concentration, and temperature on the amount of ammonia adsorption was analyzed by the spectrophotometer, and finally, the adsorption property of the hydrogel was analyzed by the scanning electron microscope (SEM). The results of scanning electron microscopy show that there are holes in the hydrogel surface that increase the rate of adsorption. Experimental data from the spectrophotometer show that the rate of ammonia adsorption increases by about 50% over 80 minutes as its concentration in the effluent increases. The inflation rate of these hydrogels was selected to be 991.52 (mg/g) under optimal conditions, and the nanomagnetic hydrogel adsorption capacity remained constant at a pH range of 4 to 9, while when the pH was below four or above 9, the capacity of adsorption shows a slight decrease. Adsorption by acrylic hydrogels is significant. There is an issue that by modifying the acrylic compounds in the production of the hydrogel, it is possible to absorb the heavy elements or colors in the best way and also to achieve high efficiency. Also, by increasing the amount of adsorbent nanomagnetic hydrogel up to 40 mg led to the adsorption of 89.16%, 32.50%, and 31.11% of ammonia in three pools of the test site, respectively. The results also show that the use of iron oxide nanoparticles in the hydrogel substrate has increased thermal stability by thermogravimetric analysis (TGA) which shows that at 650 degrees centigrade, kappa-carrageenan, hydrogels, and nanomagnetic hydrogels have a weight loss of 72.66%, 58.79%, and 52.39%, respectively. Studies have shown that the kappa-carrageenan-based hydrogel nanocomposite is more cost-effective, while it is more efficient at absorbing NH4+. Therefore, this adsorbent can be a promising material in terms of economic as well as its effectiveness in eliminating ammonia from sewage. Investigations were performed for ammonia desorption and the reusability of nanomagnetic hydrogels. Also, the rate of ammonia adsorption by nanomagnetic hydrogels after 6 cycles of recovery cycle using NaCl can be about 43% of the initial rate. All statistical studies were performed by Minitab software version 18 and considering p value = 0.05. [ABSTRACT FROM AUTHOR]

This work reports on the investigation of VHB 4910 acrylic elastomer insulating and dielectric properties. This material is widely exploited for the realization of actuators with large deformations, dielectric elastomer actuators (DEA), and belongs to the group of so-called electroactive polymers (EAP). Extensive investigations concerning its mechanical properties are available in literature while its electric behavior at working conditions has not received the same level of attention. In this work, the relative permittivity and the volume resistivity have been measured on VHB 4910 membranes under different fixed stretch conditions (λ1, λ2 = 3, 3.6, 4, 5) using circular gold electrodes sputtered onto both sides of the specimens. The measured values of relative permittivity are in fairly good agreement with the results previously published by other groups. The volume resistivity, at field values close to the operational ones, has shown a field-dependent behavior revealing dissipative properties that should be considered in real applications. Further, measurements on circular actuators verify these findings. Consequences for modeling of VHB 4910 are drawn and new material model parameters proposed to account for the value of relative permittivity at high electric fields. [ABSTRACT FROM AUTHOR]

PMMA poly(methyl methacrylate) has a large spectrum of uses as bone cements, in dentistry as denture base materials and other industrial applications. One of the main drawbacks of these materials is the residual monomer that is proven allergen and irritant. It was shown that addition of dimethyl itaconate (DMI) to the PMMA denture base systems decrease the quantity of residual monomer but, also deteriorate mechanical properties. The addition of alumina fillers in the PMMA/DMI produced composite materials results in improved mechanical properties compared with pure PMMA and additionally reduces the level of residual monomer in the composition. POLYM. COMPOS., 40:1691–1701, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract A thorough understanding of particle formation and polymer growth during emulsion polymerization is indispensable for the development of particles and products with very specific properties. This has created a demand for the detailed characterization of various properties and property distributions – and the relation between these. A method is described that enables comprehensive, simultaneous determination of the size distribution of nanoparticles and the molecular-weight distribution of the constituting polymers as a function of the particle size. The result is a complete two-dimensional distribution that details the interdependence of the two parameters. The approach comprehensively combines hydrodynamic chromatography with size-exclusion chromatography. An automated band-broadening filter has been developed to improve the accuracy of the measured distributions. The algorithm utilizes automated curve-fitting approaches to describe detected particle distributions for each horizontal slice of the 2D-LC chromatogram, and filters band broadening using calibration curves. The method has been applied to samples of complex nanoparticles comprising hydrophobic, hydrophilic and charged moieties, viz. stabilized dispersions of poly[(methyl methacrylate)- co -(butyl acrylate)- co -(methacrylic acid)]-nanoparticles in water. We consistently found that, within a single population of particles, the weight-average molecular weight increases with particle size. Graphical abstract Image 1 Highlights • Comprehensive 2D-LC was used to characterize polymeric nanoparticles. • The relation between particle size and composition was determined. • Applicable to hydrophobic, hydrophilic and charged monomer-comprising particles. • An algorithm was developed to automatically correct for HDC band broadening. • Method can be used to study particle formation during emulsion polymerization. [ABSTRACT FROM AUTHOR]

Objective. Infection control protocols in dentistry dictate that orthodontic acrylics have to be disinfected. No specific products for orthodontic acrylics are available. The objective of this study was to investigate the influence of chemical disinfectants on mechanical properties of orthodontic acrylics. Materials and Methods. 260 test specimens of two cold-curing orthodontic acrylics were manufactured. Three chemical disinfecting agents were tested: Impresept, D050 Instru-Gen, and Stammopur DR. Test specimens were stored in distilled water and divided into test groups. E-Modulus, flexural strength, macro hardness, micro hardness, average roughness, and colour change were measured. Results. Disinfection agents showed no significant influence on E-modulus. Values ranged from 1783.80 ± 163.80 MPa (Forestacryl colourless) to 2474.00 ± 135.00 MPa (Orthocryl green) after storage in distilled water. Disinfection agents performed no significant influence on flexural strength. Values ranged from 18.64±1.59 N/mm2 (Forestacryl colourless) to 25.64 ± 1.43 N/mm2 (Orthocryl green) after storage in distilled water. Orthocryl colourless showed a reduction of the macro hardness after disinfection (Stammopur DR (p≤0.001), D050 Instru-Gen (p≤0.037)). Disinfection of Orthocryl green with D050 Instru-Gen (p<0.001) and Forestacryl colourless with Impresept (p≤0.001) led to a reduction of macro hardness. Micro hardness of Orthocryl colourless altered significantly after disinfection with D050 Instru-Gen (p≤0.001). Micro hardness of Forestacryl colourless increased (Impresept (p≤0.039)) and decreased (Stammopur DR (p≤0.006) Instru-Gen (p≤0.001)) after disinfection. Average roughness did not change significantly (Orthocryl colourless). Forestacryl colourless performed a significant change after disinfection with Stammopur DR (p≤0.05). This is also true for the disinfection of Orthocryl green and Forestacryl pink with Instru-Gen (p≤0.05). Disinfection performed no significant influence on colour change. ΔE-values were in a range of 1 to 2. Conclusions. Some orthodontic acrylics disinfection caused significant changes of determined parameters. Changes were specific for the applied disinfectant and tested orthodontic acrylic. Further studies should verify the impact of long-term disinfection intervals. Thus, from manufacturers of orthodontic acrylics recommendations for appropriate disinfectants would be desirable. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the uveal and capsular biocompatibility as well as positioning stability of a new hydrophobic acrylic intraocular lens (IOL) in vivo in the rabbit model and compare it with a commercially available IOL. Setting John A Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Design Experimental study. Methods Fifteen New Zealand rabbits had the new test IOL (Clareon CNA0T0) implanted in one eye and a control IOL (Acrysof SN60WF) implanted in the contralateral eye. The test IOL is manufactured from a new hydrophobic acrylic material incorporating ultraviolet blocker and blue light filter. Its design is based on the control IOL's platform. The rabbits were followed up with weekly slitlamp evaluations, which assessed inflammatory reactions as well as capsular bag opacification. Anterior chamber depth was measured at 1 and 4 weeks post-implantation (high-frequency ultrasound). After 4 weeks, the rabbits were killed humanely and the eyes were enucleated. The anterior segment was evaluated from the posterior or Miyake-Apple view, and was then processed for complete histopathology. Results There were no statistically significant differences between test and control eyes in terms of postoperative inflammation and capsular biocompatibility, including posterior capsule opacification (P =.34, paired t test), and anterior capsule opacification (P =.53, paired t test), as observed during clinical and pathological evaluation. In vivo axial positioning for the test IOL was comparable to the control IOL and stable over time (P =.531 versus P =.788). Conclusions The new IOL showed biocompatibility and stability comparable to the control IOL. [ABSTRACT FROM AUTHOR]

Abstract Cancer vaccines targeting patient-specific tumor neoantigens have recently emerged as a promising component of the rapidly expanding immunotherapeutic armamentarium. However, neoantigenic peptides typically elicit weak CD8+ T cell responses, and so there is a need for universally applicable vaccine delivery strategies to enhance the immunogenicity of these peptides. Ideally, such vaccines could also be rapidly fabricated using chemically synthesized peptide antigens customized to an individual patient. Here, we describe a strategy for simple and rapid packaging of peptide antigens into pH-responsive nanoparticles with endosomal escape activity. Electrostatically-stabilized polyplex nanoparticles (nanoplexes) can be assembled instantaneously by mixing decalysine-modified antigenic peptides and poly(propylacrylic acid) (pPAA), a polyanion with pH-dependent, membrane destabilizing activity. These nanoplexes increase and prolong antigen uptake and presentation on MHC-I (major histocompatibility complex class I) molecules expressed by dendritic cells, resulting in enhanced activation of CD8+ T cells. Using an intranasal immunization route, nanoplex vaccines inhibit formation of lung metastases in a murine melanoma model. Additionally, nanoplex vaccines strongly synergize with the adjuvant α-galactosylceramide (α-GalCer) in stimulating robust CD8+ T cell responses, significantly increasing survival time in mice with established melanoma tumors. Collectively, these findings demonstrate that peptide/pPAA nanoplexes offer a facile and versatile platform for enhancing CD8+ T cell responses to peptide antigens, with potential to complement ongoing advancements in the development of neoantigen-targeted cancer vaccines. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Glass-metal elements with composite action based on linear adhesive connections show a high potential in terms of structural efficiency. The adhesives considered for such applications need to fulfil a wide range of requirements and generally exhibit a non-linear material behaviour. This is also the case of the two-component structural acrylic adhesive investigated in this article. For this adhesive an experimental programme is carried out to assess its structural performance and its adhesion to selected metal and glass surfaces. Furthermore, the influence of different joint dimensions on the stress-strain properties of the adhesive in glass-metal connections, under shear and tensile loading, is analysed. The best results in terms of adhesion are obtained on stainless steel surfaces grinded with an abrasive paper P150 and on the tin side of float glass, respectively. To predict the mechanical behaviour of such connections, the suitability of material models covering both classic and porous plasticity is studied by means of non-linear finite element simulations. A novel surface fitting equation is introduced to obtain stress-strain data at constant true strain rates from uniaxial tensile test results performed at constant displacement rates. A good agreement between experimental and numerical results for shear loading is achieved based just on classical elasto-plasticity formulations. For tensile loading the numerical results show that voids in the adhesive material have to be considered for a reasonable estimation. [ABSTRACT FROM AUTHOR]

Abstract: A laser method was extended and prepared for obtaining reference measurements to calibrate scale deposition thickness models for pipelines. The technique makes use of a laser device that is inserted into a pipe. Photographs of traces of laser light projected onto the internal wall of the pipe were obtained by slow‐shutter speed photography. Image processing was applied to find the shape and area of the traces. By comparison with images of a clean pipe, accurate estimations of the deposition thickness and shape can be made. The method succeeded in capturing various deposition shapes and quantifying the amount of scale present both in laboratory and field tests. The field tests were performed in a pneumatic conveying system afflicted with scaling, located in a metal production plant. [ABSTRACT FROM AUTHOR]

Magneto-rheological elastomer (MRE) is a kind of smart material based on elastomer matrix and it is divided into isotropic (i-MRE) and anisotropic MRE (a-MRE) depending on the magnetic particle arrangement. In the i-MRE, carbonyl iron particles (CIP) are randomly dispersed, while they form a chain-like structure in the a-MRE. Two manufacturing procedures of a-MRE have been introduced. The a-MRE-1 was manufactured by one-step process involving application of magnetic field and curing of matrix simultaneously. On the other hand, a-MRE-2 was manufactured by two-step process in which the magnetic field was applied to induce CIP orientation and then the matrix was cured. The microstructure and mechanical properties of MRE were characterised by scanning electron microscope, universal testing machine and dynamic mechanical analysis. The results showed that the CIP content in MRE had no effect on the cure properties. A chain-like structure existed in a-MRE-1, whereas the orientation structure of CIP in the a-MRE-2 was not as clear as that in a-MRE-1. The tensile strength of a-MRE-1 was the lowest because no interfacial reaction occurred between the CIP and the rubber molecules chain, whereas i-MRE had the highest tensile strength. [ABSTRACT FROM AUTHOR]

We determined the THz properties of 12 different adhesives which are mainly used for industrial purposes. The adhesives applied can be classified according to their chemical structure: epoxy resins, acrylic resins, and polyurethane based materials. This work represents a basis for future studies, which will concentrate on aging effects, including the absorption of water of adhesive joints. Thus, the dielectric properties of the unaged adhesives are investigated and the results of these measurements are described herein. [ABSTRACT FROM AUTHOR]

Abstract: The fabrication of an implant‐supported fixed complete denture prosthesis involves multiple clinical and laboratory steps. One of the main steps is to provide the patient with an interim fixed prosthesis to evaluate the patient's esthetic and functional needs as well as to enhance the patient's psychology before proceeding to the definitive prosthesis. Different techniques for fabricating interim prostheses have been described in the literature. This report describes an alternative technique that uses a duplicate denture made of self‐curing acrylic resin to fabricate an implant‐supported fixed interim prosthesis. The interim prosthesis was later used as a blueprint for the definitive implant‐supported hybrid prosthesis. [ABSTRACT FROM AUTHOR]

We have prepared solid sensory materials for the visual detection of cyanide in 100% water solutions and gas phases. The materials are hybrid polymers that were prepared from a palladium-containing acrylic monomer for use as sensory films and smart textiles. [ABSTRACT FROM AUTHOR]

Natural fabric such as flax and jute was considered in biaxial plain reinforcement in matrix of acrylic resin, and the composite is prepared in hand layup techniques. Fabric mass fraction of 7% was used in the matrix of composite. The samples were treated at r.t and 60 °C for the final fabrication. Scanning electron microscopy was carried out to support the microstructure effect of composite in terms of thermal change. Thermogravimetric and differential thermogravimetric analysis and residual compositional analysis with FTIR were carried out for the composite and matrix samples. The mechanical and viscoelastic properties, as well as the influence of frequency and fibers types, were evaluated, in flexural mode, by means of dynamical mechanical analysis. Glass transition (Tg) and initial decomposition (Ti) temperatures increase with incorporation of fibers into the matrix. While Ti of flax and jute composite was similar, Tg in case of flax improves than jute fabric-reinforced composite. This type of composites can be used in the automotive sector, in exterior and exterior components. [ABSTRACT FROM AUTHOR]

This study characterizes the degree of cure c, of a two‐part epoxy/acrylic photopolymer used in stereolithography, SLA. The use of solid free form fabrication has added a whole new list of thermosets with a chemical reaction—curing reaction—targeted for these specific manufacturing processes. The studied thermosetting system exhibits a fast curing reaction triggered by a UV‐light source. An innovative stepwise method to quantify the degree of cure using Raman spectroscopy is reported. This method abates the Raman noise and compensates for the weak signal of fast measurements. The Raman data processing algorithm BEADS was implemented. The technique presented here was capable of following the degree of cure of the individual components of the photopolymer. Based on the epoxy/acrylic monomers concentration (75%/25%), the degree of cure for the whole system was quantified. The experimental results were modeled using a modified phenomenological kinetics equation. This model includes the dependency of the rate of cure on the light intensity, and cure state. Based on the analysis reported here, the proposed model accurately fits the initiation, propagation, and termination phases of the cure cycle. The technique and methods presented here can potentially be integrated to in situ process monitoring with instant parameter feedback, and numerical modeling of residual stresses in additive manufacturing of thermosets. POLYM. ENG. SCI., 58:228–237, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract: Flavor compounds have been shown to interact with packaging materials either by scalping, the movement of flavorings from the food product to the package, or by flavor release, movement of flavorings from the package to the food. Work has elucidated the parameters important for the scalping of flavor compounds to polyolefin packaging materials, but very little work has been conducted examining the scalping of flavor compounds by can lining materials. Can linings composed of three different polymers, polyolefin, acrylic, epoxy, were studied for binding of volatile flavor compounds (octanal, nonanal, decanal, eugenol, d‐limonene) at room temperature over a 2‐week period. Solid phase microextraction (SPME) was used with gas chromatography mass spectrometry to identify and quantify volatile compounds. Flavor compounds were studied at concentrations around 4–1,000 ppb. Fourier transform infrared spectroscopy was used to verify can lining polymer chemistry. Almost complete binding of all five of the volatile compounds studied was observed over 9–14 days at room temperature for each of the can lining chemistries. The number of time data points limited our ability to determine the order and rate constants of binding. This model system appears to be a valuable for investigating flavor binding of polymeric can lining materials. [ABSTRACT FROM AUTHOR]

Most products in our surroundings contain adhesives, including acrylic adhesives which are used in many industry sectors. Some of these adhesives contain solvents that produce strong odors, but even adhesives which are produced without solvents can emit intensive or pungent odors. In the latter case, the odor may arise from monomers in the adhesive product, from manufacturing by-products or from degradation products. Here we analyzed several acrylic, methacrylic and benzyl acrylic adhesives to identify representative odorous contaminants. The volatile fraction of the products was extracted and isolated by solvent-assisted flavor evaporation (SAFE), then analyzed via high-resolution gas chromatography olfactometry (HRGC-O), HRGC-mass spectrometry (HRGC-MS/O) and two-dimensional HRGC-MS/O. Aroma extract dilution analysis was carried out to determine the most prominent odorants. Using this targeted odorant-analytical approach, we identified 27 odorous substances representing diverse classes of molecules, including phenols with leather-like, horse stable-like or medicinal odors, acrylates eliciting glue-like, moldy and fruity impressions, and different esters with honey-like or effervescent tablet-like smells. These results show that the odor of acrylic adhesives results from a mixture of different odorants that cannot generally be traced back to the main constituents of the product but are rather likely to stem from impurities and trace side products and other contaminants. [ABSTRACT FROM AUTHOR]

The feasibility of using supercritical CO2 as a cleaning dyeing medium to dye acrylic fibers was investigated on an industrialized unit. The influence of dyeing temperature, dyeing pressure, dyeing time, and dye concentration on the K/S values of acrylic fibers was examined using the fractional factorial design of experiments. A second-order polynomial model was established to analyze the interactions between distinct parameters and to obtain the optimal K/S values. The results showed that an excellent dyeing effect of acrylic fibers was obtained in the industrialized supercritical CO2 unit, but the dyeing effect was easily affected by variations of the dyeing parameters. In the experimental range, a calculated K/S value could be up to 6.14 with the dyeing temperature of 100℃, dyeing pressure of 26 MPa, dyeing time of 60 min, and dye concentration of 3%. The dyed acrylic fibers presented good color fastness to washing, rubbing, and light. Furthermore, a commercially acceptable levelness and reproducibility for acrylic fibers were obtained in the supercritical CO2 dyeing process. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated the release of ions and the cytotoxicity of acrylic resins incorporated with silver vanadate decorated with silver nanoparticles (AgVO3 ).Background: The inhibition of the accumulation of microorganisms on the resins is critical in preventing diseases. However, the hypothesis is that the release of ions from the incorporation of AgVO3 may be important in biocompatibility.Materials and Methods: Specimens of autopolymerising (AP) and heat-polymerising resin (HP) with AgVO3 were prepared and immersed in culture medium. The release of silver ions (Ag) and vanadium (V) was evaluated by mass spectrometry with inductively coupled plasma (ICP-MS) (n=9) and the cell viability of fibroblasts L929 by MTT (3-[4,5-dimethylthiazol- 2yl]-2,5-diphenyltetrazolium bromide) (n=12). The results were evaluated with analysis of variance (ANOVA), Tukey and Pearson correlation test (α=.05).Results: The groups containing AgVO3 presented a difference in relation to the control (0%) regarding the release of Ag and V (P<.0001). All groups showed a reduction in L929 viability when compared with the cellular control (100%) (P<.0001). In comparison with the control resins for HP, a reduction in the metabolism of cells occurred starting at 2.5% and for AP at 5% (P<.0001). A positive correlation was found between the concentration of AgVO3 and the ion release, and a negative between the ion release and the cell viability.Conclusions: Significant numbers of Ag and V ions were released from resins with higher concentrations of AgVO3 , presenting cytotoxicity for cells, suggesting that the use of low concentrations is indicated to avoid risks to patients. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the processing related errors accountable for teeth-denture base interface failure and to identify the popular materials and techniques used for denture fabrication. In six months this cross-sectional survey was accomplished to target population pool of fifty-eight prosthodontic technicians in twelve dental colleges, in five cities of Pakistan. Collection of the demographic data of the participants was followed by some technical questions to identify the possible errors accountable for teeth-denture base interface failure like the type of teeth and denture base materials used; chemical/mechanical modifications of ridge lap surface area (RLSA) of teeth; the presence of possible contaminants at the RLSA of acrylic teeth and their effective removal and some questions regarding acrylic denture packing and curing stages to assess technician's expertise. Live or telephonic interviews were conducted as per convenience by two dentists. Collected data was analyzed and interpreted using SPSS version 22. Majority of the dental technicians (91.4%) were qualified and preferred conventional acrylic teeth (91.4%) and heat cured acrylic resin (71.1%) for acrylic denture fabrication. To ensure effective bonding of teeth to the denture bases, wax elimination from teeth was ensured mostly via boiling water (98.3%) and the RLSA of teeth was modified with locking grooves (82.8%) and monomer wetting (79.3%). Boiling water (98.3%) was reported to ensure complete wax removal from acrylic teeth, most of the dental technicians used dental bench press (93.1%) for acrylic dough packing and long denture curing cycles with terminal boil. [ABSTRACT FROM AUTHOR]

Aims: Compare the mechanical and physical properties of two polishing techniques for acrylic resins under the influence of disinfection. Materials and Methods: Two hundred and eight circular samples (10 mm diameter x 3 mm height) were manufactured, with 160 for the color stability, hardness, surface roughness, and wettability (n = 10) analyses, and 48 for the scanning electron microscopy and atomic force microscopy evaluation (n = 1). Two brands of prosthesis acrylic resin, Onda Cryl and Lucitone, were used to manufacture the samples. Half of the samples were intrinsically pigmented with a purple acrylic pigment (Policor) at 7% of the total weight in powder; half of those received the mechanical polish with sand paper under constant water irrigation in a universal polishing machine at 300 rpm (control), and half received a uniform coat of a photopolymerized glaze (Megaseal) to be tested. The samples were kept immersed in distilled water for 24 h before the initial measurements (T0), afterward, they were divided into two disinfection procedures; half were disinfected through microwave energy and half through cleaning tablets (Efferdent) for 60 days (T1). Results: The glaze polished groups presented inferior chromatic stability and the pigments prevented discoloration for the glaze polish. The disinfectant solutions promoted a superficial degradation of the acrylic resin for both polishing techniques. Lucitone presented higher hardness values than Onda Cryl (P < 0.001) and the glaze technique had higher hardness values than the mechanic polish. Conclusion: The photopolymerized glaze improved some characteristics of the acrylic resin, such as the surface hardness and roughness suggesting it is an adequate polish for acrylic resins. [ABSTRACT FROM AUTHOR]

Within this work we investigate the lifetime of soft PDMS stamps as a critical parameter for the up-scaled fabrication of microstructures via nanoimprint lithography. We propose the characterization of the PDMS hardness as a suitable parameter for the stamp degradation. The increasing hardness for a larger number of imprints is attributed to resist diffusion into the PDMS volume and possibly subsequent cross-linking. Force-distance measurements with an atomic force microscope were applied to demonstrate for two acrylic materials that a lower average molecular weight leads to a faster degradation. Using a temperature-assisted UV-imprint process with an epoxy material (SU-8 2002) enabled more than 100 imprints without measurable degradation due to the complex molecular structure which we assume to reduce the resist diffusion. This can be a key development towards a higher stamp lifetime and finally an industrial realization of NIL. [ABSTRACT FROM AUTHOR]

Waterborne acrylic–cellulose nanofibrils (CNFs) nanocomposite latexes have been successfully synthesized via one-pot miniemulsion polymerization. A cationic copolymer and a low amount of anionic surfactant were used to promote the stabilization process and prevent the aggregation during storage. The effect of the CNFs content and the amount of added copolymer on the particle size and the stability of the dispersion were studied. Evidence of the binding of CNFs onto the polymer particles was supported by FE-SEM observation. Transparent nanocomposite films were obtained by casting after water evaporation and film-formation process. Investigation of the mechanical properties by dynamic mechanical analysis (DMA) and tensile testing revealed an enhancement in both the stiffness and strength of the nanocomposites, which is indicative that the in-situ polymerization in presence of CNFs did not compromise the strong reinforcing potential of CNFs. The synthesized acrylic–CNFs latexes are able to form films with promising properties for application as waterborne coatings. [ABSTRACT FROM AUTHOR]

Natural fibers have recently become attractive to researchers due to their low cost, fairly good mechanical properties, high specific strength, non-abrasive, eco-friendly, bio-degradability and biocompatibility characteristics, they are exploited as a replacement for the conventional fibers, such as glass, aramid and carbon. This study investigated the influence of fiber length and weight fraction of natural siwak fiber, with the selected length of (2, 6 and 12 mm) and weight fraction (3, 6 and 9 wt %), on some of mechanical and physical properties such as (tensile, impact and hardness), in addition to test the infrared spectroscopy FTIR of the prepared denture base resin and all of these tests were carried out at laboratory temperature. The properties of PMMA reinforced by natural fiber are mainly affected by the interfacial adhesion strength between the matrix and the fiber, and in order to improve interconnection between the siwak fiber and PMMA matrix, so the siwak fibers were treated with alkali (sodium hydroxide) solution prior to use as reinforcement materials. The results illustrated that the tensile strength, young modulus, fracture toughness and hardness tended to be improved with length and concentration ratios of siwak fiber, while the impact strength and elongation percentage at break decrease with fiber content in composite samples. [ABSTRACT FROM AUTHOR]

ABSTRACT The starch-based macroporous superabsorbent polymer (St-MP SAP) was synthesized by graft copolymerization of acrylic acid (AA)/2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto cassava starch through free radical polymerization method by using sodium bicarbonate (SHC) as porogen. The monomer conversion kinetics was investigated to determine the suitable time of adding SHC so as to produce large numbers of stable and uniform pores inside the SAP. Introduction of SHC led to the formation of increasing pores and loose structure in St-MP SAP, the decrease of shear storage modulus ( G′). With increasing SHC content, the size of the macro pores increased and the wall thickness decreased, and a large number of micropores can be observed on the pore walls. Meanwhile the equilibrium swelling ratio of St-MP SAP first increased and then decreased, and reached maximum as high as 1878 g/g and 119 g/g in distilled water and NaCl aqueous solution respectively for the sample with presence of 0.8 wt % SHC. Furthermore, the swelling rate constant ( k) increased monotonously and fast swelling was presented. The macro and micropore structure in St-MP SAP enabled water to flow by capillary effect with much fewer obstructions, and the specific surface area increased, with the result that more hydrophilic groups can get in touch with water molecules rapidly. By introduction of SHC, the water molecules which can form hydrogen bonds with St-MP SAP molecules decreased, resulting in the decrease of the binding capacity of water molecules and water retention property. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44855. [ABSTRACT FROM AUTHOR]

Background Acrylic monomers (acrylates), methacrylates and cyanoacrylates all cause asthma by respiratory sensitization. Occupational inhalation exposures occur across a variety of industries including health care and dental work, beauty, laboratory science, assembly and plastic moulding. Aims To examine notifications of occupational asthma caused by acrylic compounds from a UK-based regional surveillance scheme, in order to highlight prevalent exposures and trends in presentation. Methods Retrospective review of all cases reported to the SHIELD surveillance scheme for occupational asthma, West Midlands, UK between 1989 and 2014. Patient data were gathered on demographics, employment, asthma symptoms and diagnostic investigations including serum immunological testing, serial peak flow analysis and specific inhalation challenge tests. Descriptive statistics were used to illustrate worker characteristics and evidence for sensitization to acrylic compounds. Results There were 20 affected patients out of 1790 total cases of occupational asthma (1%); all cases were confirmed by OASYS (Occupational Asthma SYStem) analysis of serial peak flow measurements, with three additional positive specific inhalation challenge tests. Three out of 20 (15%) patients were current smokers and 11/20 (55%) were atopic. A variety of exposures and industries were implicated including: manufacturing, health care, beauty and printing and a novel presentation seen in teachers exposed to floor adhesives. Conclusions This is the largest reported series of occupational asthma caused by acrylic compounds, which remain an important aetiological factor in this disease. Exposure occurs in a variety of industries, particularly in manufacturing and is seen with other, perhaps better recognized sensitizing agents such as isocyanates and epoxy resins. [ABSTRACT FROM AUTHOR]

Alkali-soluble latex thickeners are extensively used in activities such as coating manufacturing, cosmetics, and textile industry. They increase apparent viscosity as a result of neutralization of carboxyl groups present in latex particles. Rheometry is the main method used to monitor the rheological activity of these substances. In this manuscript, we propose the use of dynamic light scattering (DLS) to get quantitative parameters and correlate them to apparent viscosity increase, confirming the results using more traditional methods. More specifically, we monitored by DLS the characteristic and average relaxation rates, as well as the width of the relaxation rate distributions. Critical changes of these parameters were observed during thickening; drastic changes at the same point were confirmed by rheometry, conductometry, and turbidimetry. [ABSTRACT FROM AUTHOR]

ABSTRACT The monomers (5-ethenyl-1-azabicyclo [2.2.2] octan-2-yl)-quinolin-4-ylmethyl acrylate (EAOQMA) and (5-ethenyl-1-azabicyclo [2.2.2] octan-2-yl)-quinolin-4-ylmethyl methacrylate (EAOQMMA) were synthesized by reacting (5-ethenyl-1-azabicyclo octan-2-yl)-quinolin-4-ylmethanol [cinchonidine] with acryloylchloride and methacryloyl chloride, respectively, in the presence of triethylamine. The homopolymers were synthesized by the free radical polymerization in tetrahydrofuran at 70 ± 2°C in nitrogen atmosphere using 2,2′-azobisisobutyronitrile as an initiator. The monomers and homopolymers were characterized by UltraViolet (UV), Fourier transform infrared, Proton-Nuclear Magnetic Resonance (1H NMR), and Carbon-13 Nuclear Magnetic Resonance (13C NMR) spectroscopic techniques. The glass transition temperature ( Tg, °C) was determined by differential scanning calorimetry. The thermal stability of the poly(EAOQMMA) was performed by thermogravimetric analysis, which showed higher thermal stability of about 706°C than that of poly(EAOQMA). The antibacterial activity of monomers and polymers has been evaluated by determining the inhibitory zone diameters against Gram-positive bacteria ( Staphylococcus aureus) and Gram-negative bacteria ( Pseudomonas aeruginosa), in which cinchonidine acrylate and Cinchonidine methacrylate homopolymer showed better activity than their corresponding monomers. Surface morphology of the monomers and polymers were examined by Scanning Electron Microscope (SEM) analysis. [ABSTRACT FROM AUTHOR]

ABSTRACT To obtain binder materials, emulsions of emulsifier-/solvent-free waterborne polyurethane-acrylic hybrids with a fixed acrylic monomer content (30 wt %) were prepared in this study. This study focused on the effect of glycidyl methacrylate (GMA)/acrylonitrile (AN) wt % on the shelf stability, mean particle size and viscosity of hybrid emulsion samples, water swelling %/dynamic mechanical thermal properties/mechanical properties of hybrid film samples, and the failure mode and adhesive strength of binder materials prepared in this study. Characterization of the chemical structures of prepolymers, hybrid materials (binder materials), and atmospheric pressure plasma-treated polyethylene (PE) has been performed by means of Fourier transformed infrared spectroscopy to determine the presence/disappearance/peak intensity change of functional groups. Various properties such as mean particle size, viscosity, Tg, water swelling %, hardness and mechanical properties, and failure mode and adhesive strength for leather/leather, control PE/leather, and plasma-treated PE/leather were found to be significantly dependent on the weight ratio of GMA/AN. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44497. [ABSTRACT FROM AUTHOR]

This paper reports a study on the effect of silicon carbide nanoparticles on the adhesion strength of steel–glass/epoxy composite joints bonded with two-part structural acrylic adhesives. The introduction of nanosilicon carbide in the two-part acrylic adhesive led to a remarkable enhancement in the shear and tensile strength of the composite joints. The shear and tensile strengths of the adhesive joints increased with adding the filler content up to 1.5 wt%, after which decreased with adding more filler content. Also, addition of nanoparticles caused a reduction in the peel strength of the joints. DSC analysis revealed thatTgvalues of the adhesives rose with increase in the nanofiller content. The equilibrium water contact angle was decreased for adhesives containing nanoparticles. SEM micrographs revealed that addition of nanoparticles altered the fracture morphology from smooth to rough fracture surfaces. [ABSTRACT FROM AUTHOR]

In this work, we report a facile and inexpensive approach which was demonstrated for the creation of hierarchical porous Al 2 O 3 /acrylic resin composites as durable, efficient and recyclable absorbents for oil/water separation. Using hexadecyl trimethyl ammonium bromide (CTAB) as a structure-directing agent, the lamellar γ-AlOOH with porous architectures was successfully prepared via a hydrothermal route. The hierarchical Al 2 O 3 clusters, as the inorganic phase of resin composites, retain the unique structure of lamellar γ-AlOOH by calcination treatment. In order to enhance the hydrophobic and oleophilic properties of Al 2 O 3 clusters, silane coupling agent (A151) was used to modify the surface of Al 2 O 3 clusters under microwave irradiation. The surface modified Al 2 O 3 clusters exhibit excellent hydrophobicity, oleophilicity and chemical stability, owing to the tight binding of the hydrophobic functional groups on the inorganic Al 2 O 3 clusters and the inherent stability of the grafted hydrophobic molecule chains. The porous Al 2 O 3 /acrylic resin composites were synthesized by suspension polymerization of butyl acrylate (BA) and methacrylic acid butyl ester (MBA) on the surface modified Al 2 O 3 clusters under microwave irradiation in the presence of coupling agents. The porous Al 2 O 3 /acrylic resin composites can effectively separate oils and organic solvents with high oil absorption rate and high oil retention capacity. Moreover, the obtained resin composites have high oil uptake capacities due to the synergy absorption of porous Al 2 O 3 clusters and acrylic resin. These excellent performances, such as excellent oil recoverability, excellent recyclability and high oil retention capacities, endow the material to be an ideal candidate to separate a variety of organic liquids from water. [ABSTRACT FROM AUTHOR]

The acrylic polymer latex was prepared successfully via semi-continuous seeded emulsion polymerization of methyl methacrylate(MMA), butyl acrylate(BA) and functional monomer butanedioicacid, 2-methylene-, 4-butylester (MBI) in water phase when mixed surfactants of tetradecyl dimethyl hydroxy propyl betaine and polyethylene glocolmono-nonylphenylether(OP-10) and 2,2'-azobis (2-methyl propion-amidine)dihydrochloride(V-50) were used to be emulsifier and initiator, respectively. The structure of the resultant latex is detected by Fourier transform infrared spectroscopy spectrum (FTIR) and differential scanning calorimetry (DSC) also confirmed that latex is a kind of random copolymer. Factors, which have an effect on the emulsion polymerization and properties of the resultant latex, have been optimized. Results show that optimum conditions for preparing the latex is as follows: the amount of emulsifier, V-50 and MBI are 7%, 0.5% and 4%, respectively. [ABSTRACT FROM AUTHOR]

Limited studies investigated the effect of recycled polymers obtained from the paint industry on concrete bond stress-slip with embedded steel bars, including whether such behavior would be similar to that imparted by virgin polymeric latexes. Around 50 concrete mixtures containing different vinyl acrylic-based polymer concentrations are tested by direct bond and beam-end methods. Test results have shown that the concrete-bar interfacial bond stresses occurring in the elastic region substantially improved with recycled and virgin polymers. At a similar polymer-to-cement ratio, concrete incorporating recycled polymers exhibited improved bond properties than mixtures prepared with virgin ones. This was indirectly related to the pigment and extender powders in the waste latex paints, thus reducing porosity and improving denseness of cement paste that strengthen the transition zone adjacent to reinforcing bars. The effect of reducing the water- to-cement ratio while adding superplasticizer to compensate the loss in workability and compressive strength was found efficient to increase the ultimate bond strength. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to measure the accuracy and the precision of the intraoral optical scanner CS3500®(Carestream Dental LLC, Atlanta, USA) in complex clinical situations as full arch rehabilitations on implants. 50 scans of the acrylic resin model were performed by using CS3500®(Carestream Dental LLC, Atlanta, USA) scanner. Each scan was compared with the virtual model derived from scanning with the laboratory scanner Dscan3®(Enhanced Geometry Solution, Bologna, Italy) to measure a possible misalignment. The alignment error was found to be 79,6 (± 12,87) μm. The measurement was taken at the level of 2 distal scan-abutments. The scanner's precision ranges from 24 to 52 μm , depending on the distance between scan-abutment. CS3500®(Carestream Dental LLC, Atlanta, USA) intraoral scanner has detected a valid device in the execution of complex rehabilitations on implants. His accuracy and precision values fall within the range established in literature to define acceptable the prosthetic fitting on full arch implant rehabilitations. [ABSTRACT FROM AUTHOR]