China
Africa
Explore chapters and articles related to this topic
Migration Studies of Biodegradable Composites
Published in Arbind Prasad, Ashwani Kumar, Kishor Kumar, Biodegradable Composites for Packaging Applications, 2023
A complex combination of cis-1,4-polyisoprene particles in a phospholipoprotein envelope and a serum comprising sugars, nucleic acids, lipids, minerals, and proteins makes up latex, a natural rubber. Type I hypersensitivity is caused by these proteins, which cause severe, rapid anaphylactic responses (Jaeger et al., 1992). The sap of the commercial rubber tree, Hevea brasiliensis, is used to make latex. Rubber trees are mostly grown in Malaysia, Indonesia, and Thailand, where they are tapped by cutting spiral or diagonal grooves in the bark and placing collecting cups to catch the flowing sap. Ammonia is applied as a preservative after the sap is collected to avoid bacterial contamination and autocoagulation. Ammonia disturbs the collected sap, resulting in a two-phase product that is centrifuged to concentrate. Although ammonia efficiently stabilizes latex, excessive amounts might cause skin discomfort. To address this issue, most producers employ a low ammonia level in conjunction with secondary preservatives. Accelerators and antioxidants are added to the concentrated material to increase the latex product’s strength, stretch, and durability. These accelerators and antioxidants have been linked to contact dermatitis, which is a type IV hypersensitivity (van Ketel, 1984). Vulcanization, a technique that includes curing the latex with heat and sulphur to facilitate cross-linking of the polymer chains, makes the latex material heat-stable and stretchy.
Elastomeric and Plastomeric Materials
Published in Narendra Pal Singh Chauhan, Functionalized Polymers, 2021
Mohsen Khodadadi Yazdi, Payam Zarrintaj, Saeed Manouchehri, Joshua D. Ramsey, Mohammad Reza Ganjali, Mohammad Reza Saeb
Natural rubber is usually extracted as milky and sticky fluid, known as latex, from the rubber tree, Hevea brasiliensis. The latex is rich in polyisoprene, which is currently used in many applications such as automotives, gloves, hoses and belts, balloons, balls, lining materials, and insulation. Natural rubber is one of the most consumed rubbers across the globe; nowadays, this elastomer is mainly manufactured through synthetic routes in large-scale petrochemical plants. However, synthetic isoprene rubber possesses a simple chemical structure compared to the more elaborate proteins that are abundant in nature (De and White 2001, Hanhi et al. 2007).
Designing for Hand and Wrist Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Latex allergies, a health hazard for both medical professionals and patients, proliferated in the 1980s and 1990s related largely to use of medical gloves of natural rubber latex (NRL), a product derived from rubber tree sap. The latex contains a protein that can cause reactions ranging from contact dermatitis to asthma symptoms to life-threatening anaphylaxis. Chowdhury and Maibach (2004) provide extensive information on the basic science and clinical management of latex intolerance. Because latex allergies can be so severe, other glove materials are now available for medical gloves. However, after Palosuo, Antoniadou, Gottrup, and Phillips (2011) reviewed the modifications made in the manufacture and use of NRL gloves in response to NRL allergies; they suggested latex gloves be reconsidered for medical use because of many highly desirable qualities. An exception is known cases of latex allergy or sensitization. Latex gloves remain widely available for non-medical use and may be a risk for allergic individuals, as “Manufacturers are not required to label home and community products which contain natural rubber” (Spina Bifida Association, 2015). Research continues to identify materials that compare more favorably with latex, to further improve medical gloves and other products made from latex substitutes.
Skin reactions to latex in dental professionals – first Croatian data
Published in International Journal of Occupational Safety and Ergonomics, 2019
Iva Japundžić, Liborija Lugović-Mihić
In the past 6 years there have been several relevant studies on this subject, although diagnostic methods were different (Table 1). In a 2011 Spanish study carried out on 620 healthcare workers, latex allergies were established in 5.9% of participants [8]. A Thai study from the same year conducted on 617 dental students recorded latex allergies in 5.0% of participants [9]. A 2012 study conducted in the USA on 804 healthcare workers showed that the frequency of allergic reactions to latex was 5.0% [10]. A 2013 South African study on 144 healthcare workers found an allergy to latex in 8.3% of participants, and a descriptive Dutch study from the same year carried out on 178 healthcare workers found the allergy in 2.8% of its participants [11,13] (Table 1).
Effect of nanofillers on radiation crosslinked natural rubber latex vulcanisates
Published in Radiation Effects and Defects in Solids, 2021
Neethu Varghese, Siby Varghese, Shybi A.A, Thomas Kurian
Natural rubber has excellent physical and chemical properties and has wide applications in different areas (1). Natural rubber latex is used for manufacturing medical products such as condoms, gloves, catheters, blood transfusion tubing due to its excellent elasticity, flexibility and biocompatibility (2). Radiation vulcanised natural rubber latex (RVNRL) has been extensively explored by various researchers since it possesses several advantages over sulphur vulcanisation such as the absence of nitrosamines, better transparency, very low cytotoxicity, etc. (3, 4).
Effects of temperature and catalytic reduction of sulfur content on kinematic viscosity and specific gravity of tire pyrolysis oil
Published in Chemical Engineering Communications, 2023
Job Bosire Omwoyo, Richard Kyalo Kimilu, John Mmari Onyari
Natural rubber trees are a source of latex, which is used to make tires (Demirbas et al. 2016). Latex is obtained from rubber trees by severing a narrow strip of the bark and allowing the latex to exude into a collecting vessel for several hours (Giroh et al. 2012). The rubber tree is primarily grown for its latex, which is used to make a variety of rubber products, for example, tires (Rodrigo et al. 2004).