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Tensile Properties of Pre-vulcanised Natural Rubber Latex Films via Hybrid Radiation and Peroxide Vulcanisations

Tensile Properties of Pre-vulcanised Natural Rubber Latex Films via Hybrid Radiation and Peroxide Vulcanisations

methods being used in natural rubber latex in- dustries; sulphur, radiation, and peroxide vul- canisations. Generally, rubber goods produced from sulphur vulcanised latex possess the most superior tensile strength among the three vul- canisation methods. However, sulphur vulcan- isation has a major drawback in regards to its by-products, i.e. nitrosamines and nitrosatables. These unwanted by-products are carcinogenic materials which may cause cancer and chemical allergies (Makuuchi, 2003; Sofian et. al., 2015a). Meanwhile, radiation vulcanisation of natural rubber latex (RVNRL) and peroxides vulcani- sation of natural rubber latex (PVNRL) have several advantages over the conventional sulphur vulcanisation such as less or absence of toxicity, free from nitrosamines and accelerator induced allergies, low in cytotoxicity, and cleaner process (Makuuchi, 2003; Pairu et. al., 2016; Sofian et. al., 2015a; Wan Manshol, 2004). These are cru- cial properties to be possessed by many health- care related rubber products, particularly pro- tective gloves, catheters and other medical and hospital supplies. For such uses, it is important that products are free of contaminants, toxic and carcinogenic components to avoid harmful effects in human beings.
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A Review on Coir Fiber Treated with natural rubber Latex as Concrete Reinforcement Material in cement Based Composites

A Review on Coir Fiber Treated with natural rubber Latex as Concrete Reinforcement Material in cement Based Composites

Coir pith and other undesirable materials are separated from the coir fiber. It is then chopped to about different length of 20mm, 25mm and 30mm and subjected to chemical treatments. Coir fibers are soaked in sodium hydroxide solution for 48 hours. Fiber were taken out, repeatedly washed with water and dried in the air. Latex compound is prepared by mixing 70% of natural rubber latex and 10% of sodium hydroxide solution and 20% of water. The latex compound and the resign solution were agitated to achieve homogenization. Then the coir fiber is dipped in the mixture about 15minutes and dried.
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Natural Rubber Latex (NRL) and rice starch as an alternative binder in wood composite industry.

Natural Rubber Latex (NRL) and rice starch as an alternative binder in wood composite industry.

Application of natural rubber latex (NRL) as wood adhesive has been on form since many years ago, and many previous researches regarding this raw material has been reported (Weeraratne et al., 1972; Hermiati et al., 2006). NRL is a milky brown, slightly viscous latex suspension which exhibits good moisture and mold resistance with no toxicity. It has been widely explored and used for the synthesis of wood adhesives especially for non-polar adherends (Pizzi, 1989) with modification done to increase its performance on polar surfaces. Besides NRL, studies on wood adhesives from variety of starch have been conducted since long time ago. Starch is a biopolymer which is renewable, widely available and biodegradable. It has been actively used as binders, glues and pastes even during ancient years (Kennedy Harry, 1989). However, starch has its main limitation of not having strong bonding capacity to glue wood based materials (Imam et al., 2001; Imam, Mao, Chen and Greene, 1999). Therefore, blending technique has been considered on starch in order to allow for physical or chemical modifications to take place on the molecules. Recent studies have emphasized on the synthesis of formaldehyde free wood adhesives through the reaction between the blend of starch with other polymers such as starch /PVOH (Imam et al., 2001) and starch/ tannin blend (Moubarik, Charrier, Allal, Charrier and Pizzi, 2010).
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Implementing Of The Harold Hotelling Theory Model In Empirical Evidence Whether Natural Rubber Latex Export And Food Animals Export Role A Play To The Economic Increase

Implementing Of The Harold Hotelling Theory Model In Empirical Evidence Whether Natural Rubber Latex Export And Food Animals Export Role A Play To The Economic Increase

Abstract: This research aims to know the effect of Natural Rubber Latex Export and Food and Animals Export on the Economic Increase. Types of research are causal research and secondary data collected from Government Statistics Agency of North Sumatera Province, Indonesia. The analysis using Smart PLS software. This research findings is the Food and Animals Export effect to the Economic Increase and show that Natural Rubber Latex Export does not influence the Economic Increase. The implications of this research have an impact on the policy of natural rubber development which is currently shrinking and it is expected that the development of new rubber industry so that the impact on Economic Increase is more real. This research originality is observed the downstream of natural rubber products whose results have scientific findings that have an impact on the economic increase.
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INFLUENCE OF NATURAL RUBBER LATEX ON PERMEABILITY OF FIBRE REINFORCED HIGH-PERFORMANCE CONCRETE

INFLUENCE OF NATURAL RUBBER LATEX ON PERMEABILITY OF FIBRE REINFORCED HIGH-PERFORMANCE CONCRETE

Abstract: In order to achieve durable concrete, there are two important aspects to be considered which are durability and impermeability. To increase the demand for Natural Rubber Latex Modified Fibre reinforced High Performance Concrete (NRLMFRHPC) produced with locally available materials such as cement , Fine aggregates , coarse aggregates, Metakaolin and Crimped Steel fibers, the concrete should be made impermeable. In the present investigation, NRLMFRHPC has been produced with locally available aggregates and mineral admixture (Metakaolin) and Natural Rubber Latex based NRLMFRHPC mixes were designed by absolute volume method. The specimen of size 100mm diameter and 50mm depth were cast and cured for 28 days and then tested for durability by using “Rapid Chloride Ion Permeability Test (RCPT), to assess the permeability characteristics of NRLMFRHPC. The experimental results indicate that Natural Rubber Latex can be utilized in producing durable Fiber Reinforced High-Performance- Concrete. The various results which indicate the effect of Steel Fibers and Natural Rubber Latex on the permeability characteristics of high-performance-concrete are presented in this paper to draw useful conclusions.
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Effect of Natural Rubber Latex on Mechanical Properties of Concrete with Manufactured Sand as a Complete Replacement to River Sand

Effect of Natural Rubber Latex on Mechanical Properties of Concrete with Manufactured Sand as a Complete Replacement to River Sand

The introduction of Natural Rubber Latex provides enhancement in Mechanical properties of Concrete in a long run. It substantially increases the Compressive Strengths, Flexural Strengths, Split Tensile strengths with a normal concrete.

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Effect of Sodium Dodecyl Sulphate and Polyoxyethylene Dodecyl Ether on the Rheological Behaviour and Stability of Natural Rubber Latex

Effect of Sodium Dodecyl Sulphate and Polyoxyethylene Dodecyl Ether on the Rheological Behaviour and Stability of Natural Rubber Latex

Surfactants are important class of material used in latexes to impart stability at the solid/liquid interface. Ionic surfactants and nonionic surfactants are known to provide elec- trostatic and steric stabilisation. In this study, two surfactants having chain length of twelve hydrocarbons were added to the natural rubber latex (NRL) respectively to determine its zeta potential values, adsorption isotherm and rheological properties. Previous study has shown that optimum stability was observed when the alkyl chain of surfactant contains twelve car- bon atoms. The zeta potential magnitude of NRL in the presence of sodium dodecyl sulphate increased as the surfactant concentration increases, while polyoxyethylene dodecyl ether did not show a significant change in zeta potential. The isotherms were of Langmuir Type 1, the amount of surfactant adsorbed per unit area at the plateau region was 6.0 × 10 −6 mol m −2 for sodium dodecyl sulphate and 2.1 × 10 −6 mol m −2 for polyoxyethylene dodecyl ether. The elastic modulus and relative viscosity of the NRL suspensions increased significantly in the presence of sodium dodecyl sulphate and also with polyoxyethylene dodecyl ether as compared to the NRL system due to stronger colloidal forces. The maximum packing volume fractions of the NRL stabilised with sodium dodecyl sulphate and polyoxyethylene dodecyl ether were found to be lower than NRL itself.
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SAFETY EVALUATION TEST ON HUMAN FOR RADIATION PREVULCANISED NATURAL RUBBER LATEX (RVNRL)

SAFETY EVALUATION TEST ON HUMAN FOR RADIATION PREVULCANISED NATURAL RUBBER LATEX (RVNRL)

Natural rubber latex (NRL) is a recognized allergen, and NRL allergy has become an important occupational health problem for health care workers (HCWs). Yong-Xin et al. (2016) have mentioned that there are three main allergens causing latex allergy, including cornstarch powder, protein of latex, and chemical additives. Three classifications of latex allergy, each with specific signs and symptoms have been identified (Katrancha and Harshberger, 2012). The first reaction is currently regarded as the most important one is natural protein which is harvested from the rubber tree itself. Besides the rubber particles, raw latex also contains the tree’s natural protein. The type of reaction caused by these proteins is classified as a Type I or immediate-type, IgE-mediated allergic reaction. The clinical symptoms related to this reaction are seen as local or generalized urticaria (hives) with edema, hay fever-like symptoms, and/or difficulty in breathing. In extreme cases anaphylactic reactions can occur which may even, although rarely, result in death. During the use of for example the latex medical glove the proteins, which tend to migrate to the surface, can come into contact with human tissues both of the user and the patient and caused allergic reactions. A lot of these proteins are destroyed or removed during processing, but often a considerable amount is still present in the final product. Galicia et al. (2015) has mentioned that even after these extreme procedures, allergenic proteins are present in NRL products that can affect the susceptible population.
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Natural Rubber Latex and Gum Arabic: A Comparison of Physico-chemical Properties

Natural Rubber Latex and Gum Arabic: A Comparison of Physico-chemical Properties

The present investigation deals with the determination of the physio-chemical properties of two commercial grade samples of local gums (Gum Arabic and Natural Rubber Latex (NRL)). The results revealed that the gum samples have high melting point that indicate thermal stability at room and moderate temperatures. The gum samples have about 95 % carbohydrate content and a corresponding high internal energy and can serve as a source of energy. The rheology of the samples revealed shear-thickening characteristics with gum Arabic being thixotropic and pseudo- plastic in nature while NRL was observed to be anti-thixotropic and rheopectic. Further results from the moisture absorption, contact angle and Fourier Transform Infrared Radioscopy (FTIR) analyses gave better insight into their hydroscopic behaviors. Gum Arabic has excellent water absorption capacity with less wettability as it consists mainly of more water-soluble compounds in comparison to Natural Rubber Latex. These insights from the study will enhance wider application of the gums with increased value-addition to the gums and the communities where they (can) thrive.
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Abstract: Fire behavior of natural rubber latex foam under different thickness conditions(d=1,2and

Abstract: Fire behavior of natural rubber latex foam under different thickness conditions(d=1,2and

According to video record, one can notice that the bottom of the three thickness samples are ignited during the experiments but the flame spread route is much different . In figure 4, red color represents the burning area and blue represents no burning region and the arrows represent the trend of flame spread. The flame of samples with d=1,2cm spread from the center to four edges. On the contrary, first of all, for the 5 cm sample, the fire spreads from the edge to the surrounding area. After a period of time, the bottom center is burned through and the fire spreads from the center and edge to the middle layer at the same time. The phenomenon show that the bottom flame spread law of natural rubber latex foam with different thickness is different , and the unburned zone ,during the second stage ,are located in four edges and middle layer ,respectively. We will further explore the parameters of flame height, mass loss rate and ,temperature and flame spread rate.
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EFFECT OF NATURAL RUBBER LATEX ON NORMAL AND HIGH STRENGTH CONCRETE

EFFECT OF NATURAL RUBBER LATEX ON NORMAL AND HIGH STRENGTH CONCRETE

The tensile strength of the concrete is difficult to measure directly, so it is measured indirectly by placing the cylinder horizontally and then applying the compressive load which will give the split tensile strength of the concrete. Here the tensile strength of the concrete was observed to increase with 0.9% addition of the natural rubber latex thereafter; it was decreased as in Graph 4. Therefore if the natural rubber latex is added in small percentage to the normal concrete, split tensile strength of the concrete is found to increase to some extent and then decrease linearly. Therefore optimum percentage of NRL is 0.9% for the tensile strength of the NRL added concrete.
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Randomized, double blind, placebo controled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

Randomized, double blind, placebo controled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

The increase in latex allergy incidence observed in the 80s was associated with the 25-fold increase in the use of latex gloves in order to prevent the transmission of increasing incidence of transmission viral diseases (mainly HIV, BHV and CHV) [20]. Although natural rubber latex exposure dramatically diminished in the sanitary environment, thanks to its functional properties, latex is the basis for manufacturing a large variety of products and there is even now a widespread distribu- tion of latex-containing products in other professional (hairdressers, food-service workers, cleaning workers, police officers) or personnel settings, including sports [21]. Therefore, due to the difficulties to completely avoid the allergen, it is recommended the specific desen- sitization of those patients, mainly with potential occu- pational exposure, because it would be expected that in the case of accidental exposure, the reaction would be less severe than in non-hyposensitized allergic patients.
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Receiver Operating Characteristics Analyses of Food and Drug Administration-Cleared Serological Assays for Natural Rubber Latex-Specific Immunoglobulin E Antibody

Receiver Operating Characteristics Analyses of Food and Drug Administration-Cleared Serological Assays for Natural Rubber Latex-Specific Immunoglobulin E Antibody

ROC analysis is uniquely suited to situations where multiple unknown complex multivariate responses are being examined simultaneously. In this case, PST with NRL (which is a com- plex mixture of numerous [⬇240] proteins) was evaluated us- ing FDA-cleared serum tests which potentially contain multi- ple similar or modified latex antigens. Although precise chemical correlations between the skin test and serum anti- body specificities are difficult to know with certainty, the pres- ence of a validated discriminator (PST) allows the mathemat- ical interpretation of diagnostic-test responses at increasing positive-negative thresholds and their comparison to the pres- ence or absence of disease. Finally, care should be exercised when interpreting negative IgE antibody results from the CAP and AlaSTAT assays, even at their manufacturers’ recom- mended positive cutoffs, since these assays misclassify approx- imately 25% of subjects who are skin test positive as IgE antibody negative (false negative). Care should also be exer- cised when interpreting positive IgE antibody results from the HY-TECH assay, even at the manufacturer’s recommended positive cutoffs, since this assay misclassifies approximately 25% of PST-negative subjects as IgE antibody positive (false positives).
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Polymer Modified Asphalt Emulsion

Polymer Modified Asphalt Emulsion

In road paving industry, asphalt emulsion is used for cold mix application such as chip seal, slurry seal, microsurfacing, cold recycled mixture and etc. Asphalt emulsion has several advantages compared to normal asphalt such as eco-friendly, easy to handle at ambient temperature and energy saving material because it does not need any heating process in its application. The history of asphalt emulsions and its application in road construction begin in the early part of 20 th century. Due to the increasing number of traffic loads and volume, the used of normal asphalt emulsion is not enough to prevent the pavement from deterioration. Nowadays, polymer modified asphalt technology is used by researcher and manufacturer in asphalt emulsion to improve the performance of asphalt emulsion. Various types of polymers can be used to prepare polymer modified asphalt emulsion such as styrene butadiene styrene (SBS) block copolymer, ethylene vinyl acetate (EVA), polyvinyl acetate (PVA), styrene butadiene rubber (SBR) latex, epoxy resin and natural rubber latex. Polymer can be added into asphalt emulsion in three ways: 1) pre-blending method, 2) simultaneous-blending method and 3) post-blending method. The blending method has important influence on polymer network distribution and will affect the performance of polymer modified asphalt emulsions. The absence of an agreed protocol has allowed various techniques to be used by testing laboratories in order to obtain asphalt emulsion residue. This paper presents an overview of the researches which have been conducted on polymer modified asphalt emulsions using various types of polymer and performance of its application.
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Effect of Natural Rubber on the Properties of Bitumen and Bituminious Mixes

Effect of Natural Rubber on the Properties of Bitumen and Bituminious Mixes

Abstract: In India the leftovers of results of regular elastic latex are stored each year frequently wild causing disjoin natural and other financial negative effects. The ecological strong waste like elastic, swim tops, gloves and so on can be reused betterly so it is useful for what's to come. Numerous investigations have been done to discover other elective material to use as modifiers in bitumen blends on the improvement of its properties and expressway quality. Concentrates still today for the most part centered around mechanical and physical attributes of rubber treated blends in which swell elastic is utilized either as option in contrast to characteristic totals or as added substance. In this exploration Natural Rubber latex (as inflatable’s) has been utilized as bitumen modifier. Common elastic changed bitumen is utilized for the prolongation of life of state streets. The need to receive elastic for the utilization of development of the streets is predominantly that it lessens the expense of development and furthermore reused elastic is utilized as it limits the natural contamination. In this examination Natural Rubber latex (as inflatable’s) has been utilized as bitumen modifier. Bitumen when contrasted with the rubber treated bitumen is bit delicate when presented to traffic burden and temperature. The Rubberized bitumen shaped decreases perpetual distortions because of over-burden out and about and in this way unaffected by the progressions in environmental temperature and improves slide obstruction. Elastic expands protection from stream of bitumen at higher temperature and improves the protection from fragile break at low temperature. The upper surface layer of the asphalt has been made of rubber treated bituminous blends. Rheological attributes of rubber treated bitumen just as fundamental properties of the actualized, rubber treated bituminous blend are exhibited. The practices of the two modifiers were examined by far reaching research facility testing and assessment. It was seen that the expansion of normal elastic gave better by and large execution in the bituminous blends. Subsequently, this shows characteristic elastic may contribute toward better adaptable streets later on. The above properties increment the administration life of rubber treated streets much of the time to in excess of hundred percent when contrasted with that of bituminous streets. Accordingly changed elastic bitumen of streets will join reserve funds with security.
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PRELIMINARY STUDY ON PEROXIDE VULCANIZATION WITH GAMMA IRRADIATION

PRELIMINARY STUDY ON PEROXIDE VULCANIZATION WITH GAMMA IRRADIATION

Peroxide vulcanization of natural rubber latex (NRL) has several advantages over the conventional vulcanization with sulphur such as less or absence of toxicity, free from nitrosamines and accelerator induced allergies, low in cytotoxicity and cleaner process (Cook et al., 1997; Makuuchi, 2003; Ma’zam et al., 1990; Pairu et al., 2016). These properties are important for many products, particularly catheters, surgical gloves and other medical and hospital supplies. For such uses, it is important that products are free of contaminants, toxic and carcinogenic components to avoid harmful effects in human beings (Roslim et al., 2015).
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Experimental Investigation of Toughness Enhancement in Cement Mortar

Experimental Investigation of Toughness Enhancement in Cement Mortar

aggregate size. The width of the cross-section of the specimen shall be not less than the 4 times the maximum aggregate size. As per the codal provisions the depth of the notch was kept as 40 mm. This was introduced during the casting process by using steel sheets. Control specimens were prepared for 1:4 and 1:5 mortar mixes and specimens with 40% replacement with glass powderand 20% replacement with natural rubber latex were prepared.

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Knowledge about occupational latex allergy amongst Thai nurses and student nurses

Knowledge about occupational latex allergy amongst Thai nurses and student nurses

Exposure to natural rubber latex can result not only in skin problems such as irritant, allergic contact dermatitis, angioedema, and itchy skin [2,5], but also respiratory problems such as rhinitis, sneezing, wheezing [3,6]. Furthermore, it can also cause serious adverse health effects such as asthma and anaphylaxis [7]. Whilst the replacement of latex gloves with non-latex or non- powder gloves has been shown to reduce the incidence of latex allergy [8], such measures may not be suitable in some developing countries due to their cost. For exam- ple, in Thailand, powdered latex gloves are still widely used [9]. In such situations, it has been argued that con- tinuing education about latex allergy is essential to sup- port the effectiveness of latex allergy prevention and control policies in hospitals [10]. Health effects of latex allergy can occur not only in health care workers but also in sensitised patients for whom they take care [11]. Thus providing latex allergy education is of importance not only for health care workers themselves but also for the health of their patients. To the best of our knowledge no study has yet reported on the levels of knowledge about latex allergy among health care workers in Thai- land. The purpose of this study was to evaluate the use of a dedicated latex-knowledge questionnaire in health care workers in Thailand and subsequently to provide an indication about the level of knowledge about latex al- lergy-related issues among Thai nurses and student nurses.
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Irritant Contact Dermatitis From a Black Henna Tattoo Without Sensitization to Para-phenylendiamine

Irritant Contact Dermatitis From a Black Henna Tattoo Without Sensitization to Para-phenylendiamine

rubber components such as thiuram, natural rubber latex, and fragrances) have been reported to cause active sensitization or allergic contact der- matitis from black henna tattoos.. 18,1[r]

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Proposal for a Council Decision concerning the signing and notification of provisional application of the International Natural Rubber Agreement 1995 on behalf of the Community. COM (95) 616 final, 5 December 1995

Proposal for a Council Decision concerning the signing and notification of provisional application of the International Natural Rubber Agreement 1995 on behalf of the Community. COM (95) 616 final, 5 December 1995

International Natural Rubber Agreement, 1987, of those members of the International Natural Rubber Agreement, 1987, which became members of this Agreement shall, with the consent of each[r]

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