Polymer-binder Ratio Research Articles

Fabrication of bulk alumina structures with humidity sensing capabilities using direct ink write technique

PurposeThe purpose of this study is to evaluate different 3D structures for humidity sensing that will enable the fabrication of complex geometries with high moisture sensitivity.Design/methodology/approachHumidity sensors based on alumina ceramics were fabricated using direct ink write (DIW) technique. Different engineered surface area, polymer binder ratio and post-processing treatment were considered to increase moisture sensitivity.FindingsIt was found that the binder ratio plays an important role in controlling the rheology of the paste during printing and determining the pore size after post-processing treatment. The sensibility of the fabricated humidity sensor was investigated by measuring its capacitance response toward relative humidity (RH) varying from 40% to 90% RH at 25°C. It is shown that using 3D lattice design, printed alumina humidity sensor could improve sensitivity up to 31.6 pF/RH%, over an order of magnitude higher than solid alumina.Originality/valueMost of the alumina humidity sensors available are films in nature because of manufacturing difficulties, which limited its potential of higher sensitivity, and thus broader applications. In this paper, a novel 3D alumina humidity sensor was fabricated using DIW 3D printing technology.

Strength and Durability of Styrene Butadiene Latex Modified Concrete with Silica Fume

This paper discussed the properties of styrene butadiene rubber (SBR) latex modified concrete. The latex modified concrete using SBR latex were prepared with various polymer-binderratios and tested for compressive strength, flexure strength, elastic modulus and rapid chloride penetration test. Latex contents were varied as 5, 10 and 15 percentages by mass of binder (cement and silica fume). The effect of the polymer-binder ratio on the properties of latex modified concrete was examined. It was concluded from the test results that the compressive strength and elastic modulus decrease with polymer binder ratio and flexural strength increasing with polymer binder ratio. Addition of latex reduces the chloride ion penetration due to latex film formation..

An investigation into electrochemical properties of poly(ether sulfone)/poly(vinyl pyrrolidone) heterogeneous cation-exchange membranes by using design of experiment method

Poly(ether sulfone) (PES)/poly(vinyl pyrrolidone) (PVP) blend heterogeneous cation exchange membranes were prepared by solution casting technique using dimethylformamide as solvent and cation exchange resin powder as functional groups agent. In this study, Taguchi experiment design method was employed for investigating the effects of controlling variables including polymer binder (PVP + PES) to total casting solution ratio, blend ratio of polymer binders (PVP to PES), resin to polymer binder ratio, and casting temperature on electrochemical characteristics of PES/PVP heterogeneous membranes. To this aim, each factor was considered at 4 different levels and therefore, 16 experiments were designed. To improve the quality of the membranes ultrasonic was used for appropriate dispersing of resin particles in the matrix of the membranes. According to the results, the averaged maximum values of 1.535 meq/g and 46.6 mV were obtained for IEC and membrane potential, respectively. Also, the highest obtained value of ion permeability tests was equal to 1.33 m/s. Finally, the synthesis conditions was optimized by considering the IEC and membrane potential as the objective functions which gave the values of 1.55 meq/g and 1.39 m/s for IEC and membrane potential, respectively, which proved that the synthesized membrane can be considered as a promising heterogeneous membrane.

Properties of Color Polymer Cement Mortar according to Polymer-binder ratio and Dosage of Pigment

Properties of Color Polymer Cement Mortar according to Polymer-binder ratio and Dosage of Pigment

Repair Mortar for Structural Sustainability

Objectives: Study on the engineering properties of fiber reinforced polymer cement mortar with incremental replacement of cement by silica fume, Granulated Blast Furnace Slag (GGBS) and Metakaoline (MK). Methods/Statistical Analysis: Cement is replaced by the additives as 5, 10 and 15 percent by weight. Polymer content (SBR) was varied as 5, 10, 15 and 20 percent by weight of water to be added. The FRP fiber addition is optimized to one percent by weight of cement in all the specimens. The intention was to study the variation in engineering properties of fiber reinforced polymer with additive replacement of binder with the additives and water with polymer. Findings: It is concluded from the test results that the compressive and flexural strength of modified mortar were improved markedly with increasing polymer binder ratio and also additive replacement of binder weight by silica fume, GGBS and Metakaoline. The results obtained has given much higher values when compared to individual addition of additives or polymer. The consistency in values of both compressive and flexural strength marks the much higher efficiency of the mortar even in lower percentage of addition of additive or polymer when added individually. Supplementary Cementing Materials (SCM) have growing importance in the construction industry, as it upgrades the economic and engineering efficiency of cement compositions. The replacement of water with polymer reduces the water binder ratio, driving to high strength and durable repair mortars. The polyester fibers addition resulted in the improvement of the mechanical properties of the composition. Applications/Improvements: Thus the fiber reinforced mortar combination is a mark in structural sustainability of not only modern but also for structural rehabilitation of historic monuments, where it can replace the ancient lime mortars with high strength and durability hand in hand.

Effects of Silica Fume Content and Polymer-Binder Ratio on Properties of Ultrarapid-Hardening Polymer-Modified Mortars

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapid-hardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrene-butadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.

Preparation and characterization of self-cleaning alumina hollow fiber membrane using the phase inversion and sintering technique

Asymmetric alumina hollow fiber membranes were prepared using the phase inversion technique followed by the sintering process at high temperatures. The ceramic suspensions were formulated by mixing alumina powder with polyethersulfone (PESf), polyethylene glycol-30-dipolyhydroxystearate and N-methyl-2-pyrrolidone (NMP) as the polymer binder, dispersant and solvent, respectively. The objectives of this study were (i) to investigate the effects of spinning parameters, namely, ceramic loading, ceramic to polymer binder ratio, different internal coagulant temperatures and air gap variation on asymmetric structure formation and (ii) to study the self-cleaning properties of alumina hollow fiber membranes. The ceramic hollow fiber membrane was characterized in terms of its viscosity, structural morphology and mechanical strength using a scanning electron microscope (SEM). The results showed that the finger-like structures in alumina hollow fiber membranes could be formed but their patterns were influenced by the ceramic suspension and spinning parameters. Variations in their morphology resulted in significant effects on the mechanical properties and permeability of ceramic hollow fiber membranes. A CuO/CeO2 catalyst was deposited onto the alumina membrane support with the catalyst distribution determined by SEM/EDX. Self-cleaning properties were examined by comparing normal cleaning and self-cleaning properties with irradiation of UV for protein rejection. The result of self-cleaning by UV showed higher bovine serum albumin (BSA) permeation due to super-hydrophilicity of the CuO/CeO2 catalyst.

비스페놀 A 및 F형 에폭시수지와 칼루마이트를 병용한 폴리머 시멘트 모르타르의 방청성 및 내구성

이 연구는 해양환경이나, 방사선 폐기물 및 가스 저장 시설과 같은 고내구성을 요하는 철근콘크리트 구조물의 내구성 향상 기법 및 장수명화 기술의 개발을 목적으로, 우수한 성능을 갖는 비스페놀 A형 및 F형 에폭시수지와 염화물 이온 흡착제인 아질산형 하이드로칼루마이트를 병용한 폴리머 시멘트 모르타르의 염화물이온 침투 저항성, 탄산화 저항성, 건조수축 및 철근부식 촉진시험을 통하여 내구성과 방청성을 비교·검토하는 것이다. 그 결과, 폴리머 결합재비에 관계없이 칼루마이트 치환에 의해 폴리머 시멘트 모르타르의 내구성이 일부 저하하는 경향을 보였으나, 이는 폴리머 결합재비의 증가와 함께 크게 개선되었다. 방청성의 경우 비스페놀 A형 및 F형 에폭시수지 사용으로 시멘트 매트릭스 내 생성된 폴리머 필름에 의한 이온 및 가스투과 저항성이 증대하였으며, 칼루마이트의 염화물이온 흡착과 아질산이온 방출에 의해 우수한 방청효과를 보였다. 이상의 연구 결과로부터 철근콘크리트의 고성능·다기능 폴리머 혼입 시멘트 모르타르 제품의 개발이 가능할 것으로 판단된다.

Effects of polymer-binder ratio and slag content on strength properties of autoclaved polymer-modified concrete

The effects of polymer-binder ratio and slag content on the strength properties of autoclaved SBR-modified concrete using ground granulated blast-furnace slag and styrene-butadiene rubber latex are examined. As results, the compressive and tensile strength of the autoclaved SBR-modified concrete using slag are higher at a slag content of 40%, and are increasing according to polymer-binder ratio. In particular, the autoclaved SBR-modified concrete with a slag content of 40% is about three times higher tensile strength than unmodified concrete. Such a high strength development is due to the improved bond between cement hydrates and aggregates because of the incorporation of SBR latex. From the point of deteriorated physical properties and changed infrared spectra, the application of autoclaving under saturated Ca(OH)2 solution immersion causes no degradation for SBR polymer films.

재유화형 분말수지와 아질산형 하이드로칼루마이트를 병용한 폴리머 시멘트 모르타르의 방청성 및 내구성

본 연구는 철근 콘크리트 구조물의 장수명화를 위해 고성능 다기능 폴리머 시멘트 복합체의 개발을 목적으로, 우수한 성능을 갖는 VA/E/MMA (Vinyl Acetate/Ethylene/Methyl Methacrylate) 터폴리머 분말수지와 아질산형 하이드로칼루마이트를 병용한 폴리머 시멘트 모르타르의 염화물이온 침투 저항성, 중성화 저항성, 건조수축 및 철근부식 촉진시험을 통하여 그 내구성과 방청성을 검토하는 것이다. 그 결과, 폴리머 결합재비에 관계없이 칼루마이트의 치환에 의해 폴리머 시멘트 모르타르의 내구성이 일부 저하하는 경향을 보였으나, 이는 폴리머 결합재비의 증가에 따라 크게 개선되었다. 방청성의 경우 VA/E/MMA 분말수지 사용으로 시멘트 매트릭스 내 생성된 폴리머 필름에 의한 이온 및 가스투과 저항성 증대와 칼루마이트의 이온교환반응에 따른 염화물 이온 흡착 및 아질산 이온을 방출하는 자기방청기능에 의하여 우수한 방청효과를 보였다. 따라서, 철근콘크리트 구조물의 장수명화를 위해 VA/E/MMA 터폴리머 분말수지와 아질산형 하이드로칼루마이트의 병용에 의해 우수한 방청성과 내구성을 갖는 폴리머 시멘트 복합체의 개발이 가능할 것으로 판단된다. Nitrite-type hydrocalumite (calumite) is a material that can adsorb the chloride ions (<TEX>$Cl^-$</TEX>)that cause the corrosion of reinforcing bars and liberate the nitrite ions (<TEX>$NO_2{^-}$</TEX>) that inhibit corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. In this study, VA/E/MMA-modified mortars with calumite were prepared with various calumite contents and polymer binder-ratios, and tested for corrosion inhibition, chloride ion penetration, carbonation and drying shrinkage. As a result, regardless of polymer-binder ratio, the replacement of ordinary Portland cement with hydrocalumite has a marked effect on the corrosion inhibiting property of the polymer-modified mortars. However, chloride ion penetration and carbonation depths are somewhat increased with higher calumite content, but can be remarkably decreased depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to increase with the polymer-binder ratio and calumite content. VA/E/MMA-Modified mortars with 10 % calumite did not satisfy KS requirements. Accordingly, a calumite content of 5 % is recommended for the VA/E/MMA-modified mortars with calumite.

하이브리드형 방식 폴리머 시멘트 슬러리의 인장특성 및 접착성

In recent years, epoxy-coated reinforcing bars have been widely used in order to prevent the corrosion of ordinary reinforcing bar. However, they have a bad balance between performance and cost. Especially, they have a brittleness properties, low bond strength to cement concrete and no good bend-ability in the field. The purpose of this study is to evaluate the tensile properties and adhesion of hybrid-type anti-corrosion polymer cement slurry (PCS). PCSs are prepared with four types polymer dispersions using fly ash and silica fume, and tested for proper coating thickness, tensile properties, adhesion to steel plate and bend-ability. From the test results, the viscosity of PCS is effected by polymer dispersion types, and is a little decreased by using fly ash. The coating thickness of PCS has a proper thickness at polymer-binder ratio of 100%. It is apparent that the coating thickness has various values according to viscosity of PCS, water-binder ratio and polymer-binder rato. PCS has a good various anticorrosion properties and physical properties such as tensile strength, adhesion and bend-ability. It is also recommended that proper coating thickness to reinforcing bar is in the ranges of 150 to for bond strength, adhesion and bend-ability. It is also expected that the coated reinforcing bar using PCS is widely used instead of epoxy coated reinforcing bar in the industrial field.

폴리머 디스퍼션을 이용한 프리팩트 콘크리트용 주입 모르타르의 배합에 관한 연구

Prepacked concrete has recently been used in the special constructions fields such as underwater concrete work, heavy-weight concrete work, underground structure work, partial repair works for damaged reinforced concrete structures. and polymer-modified mortars have been employed as grouting mortars for the prepacked concrete. The purpose of this study is to recommend the optimum mix design of polymer-modified grouting mortars for prepacked concrete. Polymer-modified mortars using SBR and EVA emulsions as admixture of grouting mortars for prepacked concrete are prepared with various mix proportions such as sand-binder ratio, fly ash replacement ratio, polymer-binder ratio. and tested for flowability, viscosity of grouting mortars, bleeding ratio, expansion ratio, flexural and compressive strengths of grouting mortars and compressive and tensile strengths of prepacked concretes. From the test results, it is apparent that polymer-modified mortars can be produced as grouting mortars when proper mix design is chosen. We can design the mix proportions of high strength mortars for prepacked concrete according to the control of mix design factors such as type of polymer, polymer-binder ratio, sand-binder ratio and fly ash replacement ratio. Water-binder ratio of plain mortars for a constant flowability value are in the ranges of 43% to 50%. SBR-modified mortar has a little water-binder ratios compared to those of plain mortar, however, EVA-modified mortar needs a high water-binder ratio due to a high viscosity of polymer dispersion. The expansion and bleeding ratios of grouting mortars are also controlled in the proper value ranges. Polymer-modified grouting mortars have good flexural. compressive and tensile strengths, are not affected with various properties with increasing fly ash replacement to cement and binder-sand ratio. In this study, SBR-modified grouting mortar with a polymer-binder ratio of 10% or less, a fly ash replacement of 10% to cement and a sand-binder ratio of 1.5 is recommended as a grouting mortar for prepacked concrete.

Strength properties of autoclaved and combined wet/dry-cured SBR-modified concretes using ground granulated blast-furnace slag

The effects of slag content and polymer–binder ratio on the strength properties of autoclaved and combined wet/dry-cured SBR-modified concretes using ground granulated blast-furnace slag (GGBS) and styrene-butadiene rubber (SBR) latex are examined. As a result, the compressive and tensile strengths of the autoclaved and combined wet/dry-cured SBR-modified concretes using GGBS reach maxima at a slag content of 40%, and increase with increasing polymer–binder ratio. In particular, the autoclaved and combined wet/dry-cured SBR-modified concretes with a slag content of 40% and a polymer–binder ratio of 20% provide about three and two times higher tensile strengths than the same-cured unmodified concretes without GGBS, respectively. Such a high strength development is attributed to the improved bonds between cement hydrates and aggregates because of the incorporation of SBR latex.

고로슬래그 미분말을 이용한 SBR혼입 폴리머 시멘트 콘크리트의 강도특성

The effects of slag content and polymer-binder ratio on the strength properties of the polymer-modified concretes using ground granulated blast-furnace slag and a styrene-butadiene rubber (SBR) latex are examined. As a result, the compressive, tensile and flexural strengths of the SBR-modified concretes using slag increase with increasing polymer-binder ratio and slag content, and maximized at a slag content of 40 ％. In particular, the SBR-modified concretes with a slag content of 40 ％ provide approximately two times higher tensile and flexural strengths than unmodified concretes. Such high strength development is attributed to the high tensile strength of SBR polymer and the improved bond between cement hydrates and aggregates because of the addition of SBR latex.

高耐水性せっこう硬化体の開発

Gypsum is widely used for the manufacture of various building materials because of its advantages such as rapid setting, good thermal insulating property and fire resistance, but their use is limited to interior finishings because of its poor water resistance. This paper deals with an improvement in the water resistance of gypsum composites by polymer modification and partial replacement of gypsum with ground granulated blast-furnace slag, silica fume and ordinary Portland cement. Polymer-modified gypsum-based composites are prepared with various polymer-binder (a mixture of gypsum and mineral admixtures) ratios, and tested for water absorption, flexural and compressive strengths before and after water immersion. In addition, the long-term water resistance of the polymer-modified gypsum-based composites with a superplasticizer are investigated by 3-y water immersion. As a result, SBR modified gypsum-based composites with optimum mix proportions are developed from the viewpoint of water resistance and strength development. The high water resistance of the gypsum-based composites is achieved by polymer modification, superplasticizer addition, and partial replacement of gypsum with the mineral admixtures.