Performance of irradiated blended cement paste composites containing ceramic waste powder towards sulfates,chlorides, and seawater attack

Within the scope of this study, blended cement pastes were prepared by replacing different proportions of ordinary Portland cement with ceramic waste powder (CWP). The hardened blended cement pastes were cured under tap water for different periods of time up to 180 days. Physico‐mechanical properties of specimens were studied in terms of free lime content, chemically combined water, compressive strength, and particle size distribution. The results manifested that the optimum content of ceramic waste which gave a marked improvement in the mechanical properties was 10% as compared to the other specimens at the same curing age. Besides that, similar specimens of the hardened blended cement paste containing 10% CWP were impregnated with unsaturated polyester and exposed to different doses of gamma rays from 10 to 50 kGy. Both the impregnated specimens that irradiated at a dose of 30 kGy and the neat blended cement paste that contained 10% ceramic waste were soaked in 1, 3, and 5% magnesium sulfate, sodium chloride solutions, and in seawater for up to 180 days. The results indicated that the composite specimens became more resistant to aggressive solutions and their durability increased as compared to the neat blended cement paste prepared under the same previous conditions. J. VINYL ADDIT. TECHNOL., 26:24–34, 2020. © 2019 Society of Plastics Engineers     

Physicomechanical properties of irradiated SBR latex polymer‐modified cement mortar composites

This study investigated the effect of styrene–butadiene‐rubber (SBR) latex/cement ratio as well as γ‐irradiation dose on physicomechanical properties of cement mortar. Specimens were prepared with a different SBR/cement mass ratio of 2.5, 5, 10, 15, and 20. Two curing methods were used: wet cure and dry cure. The best specimens were irradiated to doses of 10, 30, and 50 kGy. The compressive strength, total porosity, and bulk density were studied. The result indicated that the compressive strength, total porosity, and the bulk densities of the composites decrease with increase in the polymer cement ratios. In addition, it was observed that the compressive strength of irradiated polymer‐modified cement mortar composites was improved with the increase in the γ‐irradiation dose, and the compressive strength of mix‐cured samples was higher than those wet‐cured samples at any irradiation dose. X‐ray diffraction, thermogravimetric analysis, acid attack, and microstructure of SBR‐modified cement mortar were characterized. J. VINYL ADDIT. TECHNOL., 26:144–154, 2020. © 2019 Society of Plastics Engineers     

Influence of PP fiber and SBR latex on the mechanical properties of crumb rubber mortar

This article presents a new kind of rubber mortar modified by polypropylene fiber (PP fiber) and styrene‐butadiene rubber latex (SBR latex). The mechanical properties of this crumb rubber mortar were investigated in the research, including the compressive strength, flexural strength, flexural toughness, and flexural elasticity modulus. The test results showed that the flexural toughness index of the rubber mortar was seen to enhance by about 50–100% with the addition of PP fiber and SBR polymer latex. Due to the addition of PP fiber and SBR latex, the flexural elastic modulus of rubber mortar could further reduce by 4–27%. The three‐phase composite dispersion model of this rubber mortar was put forward. Furthermore, it was observed from scanning electron micrograph that the interfacial transition zone between the rubber particles and cement paste was enhanced by the SBR latex, and the interleaving of polymer films and rubber particles strengthen the flexibility and toughness of the mortar. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40591.     

Properties of polymer-modified cement mortar using pre-enveloping method

A new method, pre-enveloping sand with polymer, was adopted to make polymer-modified cement mortar (PCM). In the research, two kinds of latex, i.e., styrene acrylate rubber and styrene butadiene rubber, were used. The experimental results of physical and mechanical tests showed that, at the same level of polymer cement ratio, pre-enveloping method was better than normal method regarding the performance of the resulted composite. Moreover, in the condition of relatively low addition of polymer, the improvement of physical and mechanical properties, especially the resistance to cycling of freezing-thawing, by the pre-enveloping method was more significant. Additionally, it was found that styrene butadiene rubber can improve the fluidity of the mortar, and mortar with styrene acrylate rubber can maintain the same fluidity as the control sample by adding small quantities of a superplasticizer. Styrene acrylate rubber had no water-reducing ability by itself.     

Use of natural rubber prophylactics waste as a potential filler in styrene–butadiene rubber compounds

Owing to the unstable nature of the latex compound and the strict specifications in the quality of latex products such as condoms and examination gloves, the rejection in the latex industry comes to about 10 to 15% of the rubber consumed. These latex rejects contain about 95% rubber hydrocarbon of very high quality. A cost-effective technique has been developed for the reuse of natural rubber (NR) prophylacties waste in styrene–butadiene rubber (SBR). The influence of powdered latex rejects on the curing characteristics, mechanical properties, and failure behavior of SBR has been investigated. More emphasis is placed on the effect of both particle size and the loading of latex waste filler. Swelling studies were carried out to establish the degree of crosslinking of SBR and to assess the extent of interaction between the matrix and latex waste filler of varying particle sizes. A three layer model has been set up to study the diffusion of sulfur from the matrix phase to the filler phase. Scanning electron microscopy has been used to analyze the particle morphology, filler dispersion, and filler-matrix interface adhesion. The results of the study revealed that NR prophylactics rejects can be used effectively as a potential filler in SBR up to about 40 phr loading. © 1996 John Wiley & Sons, Inc.     

The effect of styrene–butadiene latex carboxylation on adhesion

Styrene–butadiene latices are widely used as binders in pigmented coatings for the paper and board industry. White pitch deposition, which is one type of surface fouling, is a well-known problem at paper machines using coated broke as a raw material. The main component of white pitch is latex, such as styrene–butadiene. The viscoelastic properties of styrene–butadiene latex have been found to affect on white pitch formation, but the effect of carboxylation has not been studied extensively. Carboxylation has traditionally performed to latices in order to increase colloidal stability, but it has also effect on mechanical properties of the latices.In this paper, we studied the adhesion potential of three styrene–butadiene latices by using a cylindrical probe tack method under dry and aqueous conditions while varying the carboxylation degree of the latex. Adhesion potential was measured using low and high energy surfaces as adherents. The results show that carboxylation influences adhesion potential of latices in both dry and aqueous environments.     

Effect of gamma irradiation on polymer modified white sand cement mortar composites

This study focuses on the substitution effect of standard sand of cement mortar by different ratios of white sand to prepare white sand cement mortar. The prepared samples were first cured under tap water for different time intervals 3, 7, 28 and 90 days. The effect of addition of 10% styrene–acrylic ester as well as the effect of different doses of gamma rays on the physico-mechanical properties of polymer modified white sand cement mortar specimens also, discussed. Compression strength test, total porosity and water absorption percentages were measured. The results were confirmed by scanning electron microscopy, and thermogravimetric analysis studies.     

Acrylonitrile butadiene nanocomposites containing different clays by latex compounding method

Considering elastomers nanocomposites, most of the works are focused on natural rubber, styrene butadiene rubber and rubber blends, while few of them deal with nitrile butadiene rubber (NBR). This article presents the reinforcing effect of two raw sodic montmorillonites (Mts) and one organoclay on NBR matrix prepared by the latex compounding method. Raw Mts increase the mechanical properties of neat matrices. A pseudoplastic behavior is observed with the incorporation of clays into the NBR latex, indicating interactions between polymer chains and clay sheets, in agreement with the results of zeta potential analysis. X‐ray diffraction evaluates changes in the interlayer distance of the clay, indicating the NBR intercalation phenomenon in all cases. Matrices with different clay proportions present variations in the mechanical properties, depending if the aggregation phenomenon is promoted. Morphological analysis of clays and nanocomposites as well as thermal analysis were performed. The variation in mechanical properties after an aging process was studied, evaluating the effects on the tensile strength, ultimate strain and 300% modulus. POLYM. ENG. SCI., 59:736–744, 2019. © 2018 Society of Plastics Engineers     

高分散性丁苯胶乳的制备及其对水泥的改性

添加传统丁苯胶乳进行改性,大大提高了水泥的力学性能,但是改性后的水泥材料流动性能差,抗压性能损失较多。为了提高添加丁苯胶乳后水泥的流动性及降低抗压性能损失,本文对丁苯胶乳进行改性,以苯乙烯与聚丁二烯作为核层、带有苯环的对苯乙烯磺酸钠作为壳层,制备出核壳型丁苯（SSBR）胶乳。把新合成的SSBR胶乳加入水泥后,对水泥力学性能进行表征,由于SSBR胶乳中与磺酸根相连的是苯环刚性链,空间位阻效应明显,添加8% SSBR胶乳水泥浆的流变指数增大为0.898,分子链强度大,水泥石的7天抗压强度损失量为2.31%,损失不明显,同时抗折强度提高17%。对SSBR胶乳改性水泥石材料力学性能的作用机理进行探究,结果表明,SSBR胶乳填充作用明显,吸附作用较强,增大水泥浆流动性能,且胶乳粒子可以与Ca²⁺络合,形成三维网状空间立体结构,从而达到增强水泥石力学性能强度,提高水泥石韧性的目的。     

Dynamic mechanical properties of SBR and EPDM vulcanisates filled with cryogenically pulverized flexible polyurethane foam particles

The dynamic mechanical properties of rubber vulcanisates filled with cryogenically pulverized polyurethane foam particles, used as a reinforcing filler, were investigated with respect to storage modulus (E′), loss modulus, and the variation of glass transition temperature. Two rubbers were using styrene–butadiene rubber (SBR) and ethylene–propylene copolymer (EPDM). The effects of filler concentration and filler characteristics (such as particle size and moisture content) were also monitored. It was found that the optimum dynamic mechanical properties of the compounds were obtained when introducing the PU particles of 40–50 parts per hundred (pph) rubber in the SBR and 30 pph in the EPDM, the properties being affected by the size of PU particles and moisture content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1129–1139, 1999     

Gamma irradiation of (styrene butadiene rubber)/(devulcanized waste rubber) blends modified by organoclay

In this study, the physicomechanical properties and morphology evolution of irradiated (styrene butadiene rubber)/(devulcanized waste rubber)/(organically modified montmorillonite) nanocomposites were realized. The improvement in the physicomechanical properties provides a possible mechanism on how organically modified montmorillonite influences the general properties of irradiated nanocomposites. X‐ray diffraction data illustrated that there is an increase in the basal spacing of sodium montmorillonite clay due to modification and/or polymer intercalation. The results of mechanical properties showed that the as‐prepared nanocomposites have superior irradiation‐resistant properties to the (styrene butadiene rubber)/(devulcanized waste rubber) blend. J. VINYL ADDIT. TECHNOL., 24:50–57, 2018. © 2015 Society of Plastics Engineers     

Investigations on the adhesion and interfacial properties of polyurethane foam/thermoplastic materials

The adhesion and interfacial properties of polyurethane (PU) foams with thermoplastic (TP) materials were investigated using different techniques. The adhesion performance of PU foam with TP materials was evaluated using the peel test method, and the adhesion durability was checked after different climate treatments. X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurements were used to study the surface and interface morphology of PU foam and TP material system. Three types of PU foam samples which differ in their composition and also five commercially available TP blends systems, based on poly(carbonate), poly(styrene‐co‐maleic anhydride), poly(acrylonitrile‐butadiene‐styrene), and silicone acrylate rubber have been used. The slow reacting foam shows the best adhesion properties with all the TP materials. The climate treatments strongly effected the PU foam adhesion durability with poly(carbonate) containing TP materials (70–80% loss in adhesion), but nearly no effect with poly(styrene‐co‐maleic anhydride). The samples with lowered adhesion could be separated by peeling without visible foam residues on the TP surface. AFM, XPS, and surface tension studies have shown that the surface properties of the TP material are still governed by the PU foam. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 479–488, 2007     

Utilization of emulsion polymer for preparing bagasse fibers polymer–cement composites

Sugarcane‐bagasse fiber–polymer cement composites were prepared using three lattices namely, styrene butadiene, vinyl ester, and styrene acrylic. The lattices percentages ranged between 3 and 21% from the weight of the mixture. The pressed samples were irradiated at different irradiation doses by using electron beam (EB) accelerator. Comparative studies have been made for physicomechanical properties of unirradiated and irradiated samples. The results indicated that the flexural strength, modulus of elasticity, and impact toughness of the composites increase with the increasing polymer content up to 9.9 and 15% of styrene butadiene, vinyl ester, and acrylic styrene, and then decrease. It was also observed that the maximum values of flexural strength and modulus of elasticity obtained at EB‐irradiation dose 45, 40, and 25 kGy for styrene butadiene, acrylic ester, and vinyl ester, respectively. The impact strength of the composites did not significantly improve above 10 kGy. The average values of hardness of irradiated composites were higher than that those of unirradiated and control composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of curing time on the physicomechanical characteristics of the hardened cement pastes containing limestone

The effect of curing time on the physico-mechanical properties of the hardened Portland cement pastes containing limestone was studied. Five cement-limestone blends were prepared using 0%, 5%, 10%, 15%, and 20% of limestone as a partial substituent of Portland cement. The cement pastes were prepared using the standard water of consistency of 0.255, 0.255, 0.258, 0.261, and 0.263, respectively. The fresh pastes, thus produced, were moulded into 2×2×2-cm cubes. The pastes were first cured within the moulds at 100% relative humidity for 24 h, then the specimens were demoulded and cured under tap water for 3, 7, 14, and 28 days. At each hydration age, the hardened pastes were tested for bulk density, compressive strength, differential scanning calorimetery (DSC), and X-ray diffraction analysis (XRD). The results obtained were related as much as possible to the mechanical properties of the hardened cement pastes. The inclusion of limestone results in a notable improvement of the mechanical properties of the cement pastes containing limestone.     

水泥改性用丁苯胶乳的合成

采用种子乳液聚合法制备了丁苯共聚物/水泥复合材料专用丁苯胶乳,考察了复合乳化剂体系、种子胶乳用量、极性单体种类、聚合温度及加料方式等对乳胶粒尺寸及其分布和胶乳稳定性等的影响。结果表明,在小粒径种子体存在下,分批加乳化剂的加料方式是合成水泥专用丁苯胶乳的有效途径之一,平均粒径小且粒径分布窄的丁苯胶乳具有较好的稳定性。采用复合乳化剂体系、添加少量带极性的第三单体等可以较好地提高丁苯胶乳的化学和机械稳定性。     

Reinforcement of acrylonitrile butadiene rubber with waste rubber ash using ionizing radiation

Composites of acrylonitrile butadiene rubber with waste rubber ash (WRA) were prepared in the laboratory by a two‐roll mill. Gamma radiation at different doses (0 to 150 kGy) was applied to curing of acrylonitrile butadiene rubber composites loaded with reinforcement filler (ash powder, 5–40 parts by weight per hundred parts of rubber [phr]). WRA was characterized by Fourier‐transform infrared spectroscopy and X‐ray diffraction. Mechanical and thermal properties of prepared composites were investigated. The results show that the concentration of WRA up to 40 phr and irradiation dose up to 100 kGy improve the mechanical properties of composites. On the other hand, the thermal stability of the composites improved by adding 40 phr of WRA. J. VINYL ADDIT. TECHNOL., 23:117–124, 2017. © 2015 Society of Plastics Engineers     

Latex influence on the mechanical behavior and durability of cementitious materials

The results of an experimental program conducted on latex-modified mortars are presented in this article. These mortars have become of growing interest in the field of construction. They were used as superplasticizers, or water reducers, for finishing work applications and for repairs, coatings, and waterproofing. This study is about using two polymers (latex), i.e. styrene–butadiene rubber and styrene–acrylic, in order to assess their performance in replacing cement in mortars. A series of mortar mixtures, containing 0, 2.5, 5, 10, 15, and 20% of solid polymer latex (by weight), were prepared and tested in the fresh and hardened states. The test parameters include the fluidity, compressive and flexural strengths, porosity accessible to water, adhesion to clay bricks, and cementitious substrates. The experimental results showed that substituting cement into modified mortars improves their fluidity and adhesion. In the case of clay substrates, a cohesive failure occurs within the substrate layer beyond 10% of substitution, while the rupture takes place at the interface for all formulations tested on cementitious substrates. It was also noted that the flexural tensile strength improved beyond 60 days. However, the compressive strength of polymer mortars decreased with the substitution rate of cement, for all maturities considered. However, for porosity accessible to water, the results follow a linear function, with an inflection at 5% of latex substitution.     

Influence of calcium carbonate added to the SBS rubber formulation on the surface modifications produced by halogenation

To improve the adhesion properties of styrene–butadiene–styrene (SBS) rubber sole to polyurethane adhesive, surface treatments are required, of which halogenation with trichloroisocyanuric acid (TCI) solutions in organic solvents is the most commonly used treatment in the footwear industry. Calcium carbonate filler is commonly added to improve the mechanical properties and to reduce shining of SBS rubber formulations. The influence of the filler on the effectiveness of surface chlorination of SBS rubber had not been considered in the existing literature. Therefore, 10 wt% calcium carbonate filler was added to the SBS rubber formulation and the surface modifications and adhesion properties produced by treatment with TCI solutions were investigated. The resulting surface modifications and adhesion were compared to those obtained in unfilled SBS rubber. It is shown that the treatment with TCI solutions was less effective in the calcium-carbonate-filled SBS rubber and a lower peel strength to polyurethane adhesive was obtained; however, a cohesive failure in the rubber was always obtained.     

Toughening and Compatibilization of Acrylonitrile–Butadiene–Styrene/Poly (Ethylene Terephthalate) Blends Using an Oxazoline-Functionalized Impact Modifier

An oxazoline-functionalized core–shell impact modifier was synthesized between aminoethanol and acrylonitrile/butadiene/styrene high rubber powder. According to the Fourier transform infrared spectroscopy test, the nitrile groups were partially converted into oxazoline groups successfully. The oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder was used as an impact modifier for acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends. The differential scanning calorimeter and rheological tests demonstrated that poly(ethylene terephthalate) was partially miscible with acrylonitrile–butadiene–styrene, because the oxazoline groups of oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder reacted with the end groups of poly(ethylene terephthalate). The results of scanning electron microscopy indicated that the morphology of acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends with proper oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder content was improved significantly. The best mechanical properties were achieved, When 6 wt% oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder was added into acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends.     

Studies on the Cell Structure and Mechanical Properties of NR/Latex Reclaim/HSR Based Micrqcellular Sheets

In natural rubber/high styrene resin microcellular sheets, part of natural rubber was replaced by latex reclaim prepared from waste latex products. The mechanical properties and cell structure of the products were evaluated. It was found that latex reclaim can replace about 30% of natural rubber without affecting the technical properties of the microcellular sheets.