High Water Resistance Research Articles

Preparation and Characterization of Acrylate Copolymers Modified by Fluorine and Silicon for Application in Release Films

Fluorine-silicone acrylate copolymers were synthesized with vinyltriethoxysilane (VTES), methyl hexafluorobutyl acrylate (HFMA), and other acrylate monomers by free radical polymerization. Further studies were directed at the water absorption ratio, contact angle and anti-adhesive performance of the films. The results indicated that the copolymers had narrow molecular weight distribution and high temperature stability. The films coated by copolymers showed excellent water/oil repellency with the contact angles of water and diiodomethane of 108.2° and 78.0°, respectively. Anti-adhesive performance testing demonstrated that the films had low peel strength, high residual adhesion rate and excellent water and solvent resistance.

A new approach for evaluating the water resistance of sunscreens on consumers: tap water vs. salt water vs. chlorine water

An efficient sunscreen product needs to offer broad spectrum photostable UV protection during consumer use. Water resistance has become an additional criterion requested by consumers spending time near water or outdoors. Polymers generally provide water resistance to formulations and are critical to the formation and stability of a sunscreen film on skin when exposed to water. The present work introduces a new in vivo screening approach to measure water resistance using UVA-induced fluorescence imaging. The approach has been applied to several formulations containing different polymers and compared to commercial products, for the three main water types: tap, salt and chlorinated water. All testing has been performed on the forearms of 10 subjects using UVA imaging. In addition, the skin whitening has been measured for all formulations on five subjects when exposed to water by visible light imaging. Our approach showed clear differences in water resistance values among the formulations tested, reflecting the importance of the formulation and the polymers used. The method proved capable of discriminating not only sunscreen performances with different water proofing ingredients but also water specific sunscreens such as a beach dedicated product showing a 20% higher resistance to salt water vs. tap and chlorine waters. The use of UVA-induced fluorescence imaging on skin proved a useful in vivo approach for measuring the water resistance performances for various sunscreen lotions with a wide range of skin whitening effects in water. Our method showed how high water resistance can be combined in a Wet skin(®) sunscreen with superior non whitening effect on the skin.

Release of volatile compounds and biodegradability of active soy protein lignin blend films with added citronella essential oil

Active biodegradable bilayer films based on soy protein isolate, lignin and formaldehyde were developed. These films showed high water resistance and malleability, making them suitable for use in extreme environmental conditions. The presence of lignin in the formulation provided greater protection against light, especially UV. With the addition of 3% w/w citronella essential oil, the films showed good antifungal activity against Fusarium oxysporum pathogen microorganism in bananas. When the bananas were covered by the films during storage, there was a noticeable reduction in total aerobic mesophiles and moulds and yeasts. As the films aged (1, 3, 6 months), in both controlled and environmental conditions, the main active compounds in the citronella essential oil, citronellal and geraniol, were progressively released from the film matrix, citronellal more than geraniol. Over 30 days of soil degradation, the films lost around 30% of weight irrespective of the conditioning time.

Soy protein isolate films with improved property via a facile surface coating

A facile surface coating approach was explored, in this paper, for soy protein isolate (SPI) films to overcome their drawbacks of high stiffness and low water resistance. Scanning electron microscope images confirmed the formation of polyurethane (PU)-coated SPI films with variable thickness of PU coating layer from 2.46 to 14.54μm. The optical transmittance and appearance of the coated films were maintained well compared with the neat SPI film owing to the low thickness of PU layer. The surface hydrophobicity of SPI film was greatly increased after being coated with PU, and the neat and coated SPI films showed exponential and linear decline profiles of contact angle with time, respectively. The water resistance, water vapor barrier, and mechanical properties of the neat SPI film were enhanced upon coated with PU, and the properties can be well modulated controlling the thickness of coating layer. Furthermore, good interfacial interactions were existed between the matrix and coating layer, suggesting of durability of the resultant trilayer films. The results indicated that coating SPI with a polymer with good water barrier property and toughness was an effective manner for fabrication of SPI-based materials with improved properties.

Water-Resistant Material from Recovered Fibers and Acrylic Emulsion Terpolymer

Styrene (SM), methyl methacrylate (MMA), and butyl acrylate (BA) were used to synthesize a polyacrylic emulsion by core-shell emulsion polymerization. The solid content of the emulsion reached 40% using reasonable reactive emulsifier contents and feeding modes. Then, the emulsion and a fiber were dispersed, coated, and dried together. Finally, fiber-based water-resistant material was successfully fabricated. The experimental results showed that under the conditions of a monomer mass ratio of 1:1:1 and a mass ratio of polyacrylic emulsion to fiber of 2:1, the Cobb value of the material reached 5.0 g/m2. The tensile strength, elongation, and breaking length were 7.4225 kN/m, 1.0%, and 11.706 km, respectively. Using scanning electron microscopy (SEM) to analyze the surface morphology and internal structure of products, the reasons for the high water resistance of fiber-based material was due to the bonding and filling effects of the polyacrylic emulsion on the fibers. For tightly bound fibers, the porous structures formed in fiber-based boards were reduced. On the other hand, the polyacrylic emulsion filled the gaps between fibers. This filling effect led to a continuous structure, and the water resistance of the material was further enhanced.

Physical properties of park soils of the objects of landscape architecture

Here the comparative characteristics of the physical properties of park soils, viz., anthropogenically transformed and engineered soils of the objects of landscape architecture, are given. The mechanical strength of aggregates, density, and aggregate physical properties to characterize the soil and agro-physical and environmental condition of soil objects of landscape architecture and establish the similarities or differences of engineered soil objects with zonal soils are described. We studied the physical properties of soils of different structural and functional elements of the landscape and the regular area of the Arkhangelskoe memorial estate. The structural state of the park soils is characterized as good. The engineered soils of the regular area of the park appear to have excessively high water resistance, while the postagrigenic sod-podzolic soils of the landscape area of the park are absolutely water resistant.

Effect of surface treatments on natural cork: surface energy, adhesion, and acoustic insulation

Cork is one of the finest natural materials with high acoustic insulation properties due to its porous structure. In addition, cork presents high water resistance due to its hydrophobic nature. In many applications, cork panels need to be bonded to other materials for manufacturing composite materials or agglomerated cork sheets. In this case, its lack of wettability becomes an important disadvantage. This paper aims to improve the wettability of cork by silanization, atmospheric plasma treatment, and vacuum plasma treatment. The processing conditions of the three treatments were optimized. The surface characterization was performed by surface energy, roughness, and attenuated total reflectance-Fourier transform infrared spectroscopy measurements. Pull-off adherence and peel tests were carried out to evaluate the performance of the treatments with an epoxy adhesive. Plasma treatment of cork plates could be a useful tool to enhance adhesion properties in the manufacturing process of cork sandwich panels or other applications where it could be joined to any material.

Effects of phosphoric acid and phosphates on magnesium oxysulfate cement

Magnesium oxysulfate (MOS) cement is a promising material for fire-proofing and insulation applications. Here, we have studied the effects of phosphoric acid and phosphates (H3PO4, KH2PO4, K3PO4 and K2HPO4) on the setting time, mechanical strength and water resistance of MOS cement. X-ray diffraction was used to examine phase composition, and analytical reagents were used to prepare samples of the new phase found so that it would be examined by chemical and thermogravimetric analyses. Adding phosphoric acid and phosphates can extend the setting time and improve the compressive strength and water resistance of MOS cement by changing the hydration process of MgO and the phase composition. A new subsulfate phase 5Mg(OH)2·MgSO4·7H2O (517 phase) is formed, which is needle-like and insoluble in water. Phosphoric acid or phosphates ionize in solution to form H2PO4−, HPO42− and/or PO43−, and these anions adsorb onto [Mg(OH)(H2O)x]+ to inhibit the formation of Mg(OH)2 and further promote the generation of a new magnesium subsulfate phase, leading to the compact structure, high mechanical strength and good water resistance of MOS cement. The improvement produced by adding phosphoric acid or phosphates to MOS cement follows the order of H3PO4 = KH2PO4 ≫ K2HPO4 > K3PO4.

Fabrication of Sr0.5Ba0.5Nb2O6 Nanocrystallite‐Precipitated Transparent Phosphate Glass‐Ceramics

Transparent (Sr0.5Ba0.5)Nb2O6 (SBN50) nanocrystallite‐precipitated phosphate glass‐ceramics were prepared by a conventional glass‐ceramic process. x(SrO–BaO–2Nb2O5) − (100–4x)P2O5 (xSBNP) glasses with a refractive index of 1.9–2.0 exhibited high water resistance owing to the presence of Q0 and Q1 phosphate units. Both bulk and surface crystallization of the SBN50 phase were observed in 20SBNP and 21SBNP glass‐ceramics. Although the nominal content of SBN50 crystals in the 21SBNP glass was larger than that in the 20SBNP glass, the latter exhibited better crystallinity of SBN50 and a higher number density of precipitated SBN nanocrystallites. By tuning the two‐step heat‐treatment and the chemical composition, transparent SBN50‐precipitated glass‐ceramics were successfully obtained. Given that no remarkable increase of the relative dielectric constants was observed after crystallization of the SBN50 nanocrystallites, it is postulated that the relative dielectric constant of the bulk is mainly governed by the amorphous phosphate region, and that the contribution of precipitation of the SBN50 nanocrystallites to the dielectric constant is not very significant in this system.

Silk Fibroin/Hyaluronic Acid Blend Film with Good Water Stability and Cytocompatibility

Stimulating cell proliferation is a challenge in the field of silk fibroin-based biomaterials. In this study, silk fibroin/hyaluronic acid blend films were prepared by a casting method using carbodiimide as a cross-linking agent. Carbodiimide induced silk fibroin to form Silk I crystal structure which was not affected by the presence of hyaluronic acid. The films showed high water resistance. In vitro, the performance of these films was assessed by seeding L929 cells. The results indicated that the silk fibroin/hyaluronic acid blend films with the blend ratio of 80/20 and 60/40 promoted cell proliferation compared with the pure silk fibroin or hyaluronic acid film. These results suggest that silk fibroin/hyaluronic acid blend films are water stable and cytocompatible materials which are expected to be useful in biomedical applications.

Performance of Nanomodified Asphalt Binder and Mixture

The nanopowdered VP108 was selected and applied into the base asphalt binder and mixture. The Marshall binder and mixture tests were conducted to evaluate the mechanical and pavement performance of base and VP108 modified asphalt binders and mixtures. The test results present that the penetration, softening point, penetration index and ductility of VP108 modified asphalt binder improved compared to the base asphalt binder. The mixture test results display that the compression strength, water susceptibility, resilient modulus and cleavage strength of VP108 modified asphalt mixture enhance compared to the base asphalt mixture. Therefore, the overall performance of VP108 modified asphalt binder and mixture improves compared to the base asphalt binder and mixture, such as the high temperature performance, resilient modulus and water resistance property.

Influence of the chemical structure of poly(urea-urethane-siloxane)s on their morphological, surface and thermal properties

Segmented poly(urethane-urea-siloxane)s (PUUS) were synthesized using 4,4′-methylenediphenyl diisocyanate (MDI) and ethylene diamine (ED) as the hard segment components and hydroxypropyl-terminated poly(dimethylsiloxane) (PDMS) as the soft segment component, where the hard segment content ranged from 38 to 65 wt%. Segmented PUUSs were prepared by a two-step polymerization procedure in tetrahydrofuran/N-methylpyrrolidone (THF/NMP) mixture with a large proportion of polar solvent. The structure, composition and hard segment length were determined by 13C NMR and two-dimensional correlation spectroscopy. Thermal, mechanical, small-angle X-ray scattering and hydrogen bonding analyses indicated the formation of the microphase-separated copolymers with high tensile strength. Globular superstructures observed in the copolymer films by scanning electron microscopy (SEM) and atomic force microscopy (AFM) were probably arisen from the microstructural organization of the MDI-ED segments, depending on their content and length. The PUUS copolymers showed high water resistance and became more hydrophobic with increasing weight fraction of PDMS.

Comparative study on the blends of PBS/thermoplastic starch prepared from waxy and normal corn starches

AbstractIn this study, waxy (0% amylose) and normal (26% amylose) corn starches were used to prepare thermoplastic starch (WTPS and NTPS, respectively). Furthermore, comparative blends of poly (butylene succinate) (PBS) and WTPS and NTPS were prepared for investigating the effect of starch type and PBS content on the properties of PBS/TPS blends. Morphology, processability, mechanical properties, water resistance, and thermal stability of the blends were evaluated. The results showed that the plasticization and processing of waxy corn starch were more easily performed than normal corn starch. The melt flow index, tensile properties, water resistance, and thermo stability of the PBS/TPS blends increased significantly with increasing PBS content. In addition, compared with the PBS/NTPS blends, the combination of PBS and WTPS could gain some excellent performances such as good processability, superior mechanical properties, and higher water resistance.

Physical Characterization and Desulfurization of Biobriquette Using Calcium-Based Adsorbent

Combustion of coal and co-combustion of their co-fuel contribute to gas emissions. Among the gas emissions are SOx, NOx, CO and CO2. Introduction of calcium based adsorbent is addressed to absorb SO2 that release to the atmosphere during the combustion process. Objective of the research is at first to observe the physical characteristics of biobriquettes as a function of briquette compositions (coal to palm kernel shell ratios) and Ca/S ratios (Ca in adsorbent and S in briquette) using a natural adsorbent (shellfish waste). The second objective is to investigate desulfurization characteristics as a function of Ca/S ratios and desulfurization temperatures at coal to palm kernel shell ratio of 90:10 (wt %). Ratios of coal to palm kernel shell in this study are 90:10, 80:20, 70:30, 60:40 and 50:50; and Ca/S ratios are 1:1, 1.25:1, 1.5:1, 1.75:1 and 2:1. Binding agent used is the mixture of Jatropha curcas seeds and starch as much as 10% (wt). It was found that introducing the palm kernel shell and adsorbents in the coal briquette affect the water resistant and compressive strength. The highest water resistance and compressive strength were 5,165 second and 34 kg/cm 2 , respectively. The lowest SO2 level found in this study was 1 ppm for all Ca/S ratios, except for 1:1.

Mechanical and other characteristics of cellulose ester bonded with modified cardanol from cashew nut shells and additional aliphatic and aromatic components

Novel cellulose-based bioplastics, mainly using inedible plant resources, were produced by bonding cellulose diacetate (CDA), a modified cardanol, and additional aliphatic and aromatic components. Cardanol is a phenol derivative with a linear unsaturated hydrocarbon side chain (carbon number: 15), derived from cashew nut shells. Esterification of the modified cardanol (3-pentadecylphenoxy acetic acid: PAA) and CDA resulted in a thermoplastic PAA-bonded CDA with high tenacity (long elongation while keeping maximum bending strength), heat resistance, and water resistance. These properties were better than those of a conventional CDA composite consisting of CDA and a conventional plasticizer. By comparing the PAA-bonded CDA with a CDA bonded with stearic acid (SA), which has a linear structure similar to that of PAA’s side chain but has no phenyl part, it was suggested that the linear side chain in PAA has a main role in these prominent properties of the PAA-bonded CDA, while the phenyl part in PAA has pronounced effects on its maximum bending strength and water resistance. Additional bonding of linear alkanoic acids, especially SA as aliphatic components improved the PAA-bonded CDA’s impact strength, and additional bonding of benzoic acid (BA) as an aromatic component further increased its maximum bending strength and elastic modulus. These components improved the thermoplasticity and water resistance of the PAA-bonded CDA while maintaining its high heat resistance relatively well.

Corrosion resistance of novel silane-functional polybenzoxazine coating on steel

A novel silane-functional polybenzoxazine (PB-TMOS) coating, with silane groups that can bond to the substrate, was prepared through a dip-coating and thermal curing method. The coating properties were investigated by Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy, static contact angle measurement, electrochemical and accelerated corrosion tests. The corrosion resistant performance of PB-TMOS coated specimens was considerably enhanced by the high hydrophobicity and water resistance resulted from the dual cross-linking network of polybenzoxazine and Si–O–Si in PB-TMOS matrix.

Geological Evaluation of Puzzle Reservoirs in Putaohua Reservoir of Weixing Oilfield

Low energy sedimentary environment with weak water power and high salinity of formation water are the main requirements of low-resistance oil layer development. Whereas part of formation penetrated by hydrocarbon migration, which shows larger bend degrees of conductive tunnels in formation and higher resistivity measurement due to the oxidization of the residual crude oil, forms high-resistance water layer. Because of the complexity of accumulation conditions, these two difficult reservoirs exist in Putaohua reservoir of Weixing oilfield widely. Combined with these accumulation regularities, this paper analyzes and summarizes the complex oil and water distribution characteristics, provide recognition means, so as to enhance the logging evaluation precision of these two difficult reservoirs effectively.

Improvement of hydrothermal stability of zeolitic imidazolate frameworks

The metal-organic framework ZIF-8, which undergoes hydrolysis under hydrothermal conditions, is endowed with high water-resistance after a shell-ligand-exchange-reaction. The stabilized ZIF-8 retains its structural characteristics with improved application performances in adsorption and membrane separation.

Amphiphobic fluorinated polyurethane composite microfibrous membranes with robust waterproof and breathable performances

Amphiphobic, microporous polyurethane (PU) composite microfibrous membranes exhibiting robust waterproof and breathable performances were prepared by the introduction of a novel synthesized fluorinated PU (FPU) containing head perfluoroalkane segment. By employing the FPU incorporation, the pristine PU membranes were endowed with the superhydrophobicity with water contact angle of 156° and the oleophobicity with oil contact angle of 145°. The role of FPU for the tuning of the morphology, surface wettability and mechanical property of resultant membranes were discussed, and a plausible two-step break mechanism upon the external stress is proposed. The quantitative fractal dimension analysis using N2 adsorption method has confirmed the correlation between the hierarchical roughness and amphiphobicity. Furthermore, the as-prepared membranes exhibited high water resistance (39.3 kPa), good air permeability (8.46 L m−2 s−1) and water vapor transmittance (0.384 kg m−2 h−1), and comparable tensile strength (10 MPa), suggesting their use as promising materials for a variety of potential applications in protective clothing, bioseparation, membrane distillation, tissue engineering and catalyst carriers, etc., and also provided new insight into the design and development of functional microfibrous membranes through FPU incorporation.

Effect of Briquetting Process Variables on Hygroscopic Property of Water Hyacinth Briquettes

The knowledge of water resistance capacity of briquettes is important in order to determine how sensitive the produced briquettes are to moisture change during storage. The relative changes in length and diameter of briquettes during immersion in water for 6 hours were investigated. This was conducted to determine hygroscopic property of produced briquettes under process variables levels of binder (10, 20, 30, 40, and 50%) by weight of residue, compaction pressure (3.0, 5.0, 7.0, and 9.0 MPa) and particle size (0.5, 1.6, and 4 mm of dried and ground water hyacinth). Data was statistically analysed using Analysis of Variance, the Duncan Multiple Range Test, and descriptive statistics. The relative change in length of briquettes with process variables ranged significantly from % to % (binder), % to % (compaction pressure), and % to % (particle size) (). Furthermore, the relative change in diameter of briquettes with binder, compaction pressure, and particle size varied significantly from % to %, % to %, and % to %, respectively (). This study suggests optimum process variables required to produce briquettes of high water resistance capacity for humid environments like the Niger Delta, Nigeria, as 50% (binder proportion), 9 MPa (compaction pressure), and 0.5 mm (particle size).