Colloidal and rheological properties of natural rubber latex concentrated with hydroxyethyl cellulose and sodium dodecyl sulphate

2021 ◽  
pp. 52034
Author(s):  
Manuela Walteros‐León ◽  
Mónica Lucía Álvarez‐Láinez
Keyword(s):  
Natural Rubber ◽  
Rheological Properties ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Natural Rubber Latex ◽  
Hydroxyethyl Cellulose ◽  
Rubber Latex

Surfactant Treatment and Leaching Combination Process for Preparation of Deproteinized Natural Rubber Latex

2015 ◽  
Vol 659 ◽  
pp. 500-504
Author(s):  
Jirapornchai Suksaeree ◽  
Wirach Taweepreda ◽  
Wiwat Pichayakorn
Keyword(s):  
Natural Rubber ◽  
Skin Irritation ◽  
Sodium Dodecyl ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Combination Process ◽  
Surfactant Treatment ◽  
Leaching Process ◽  
Sodium Lauryl Ether Sulfate ◽  
Cocamidopropyl Betaine

This study aimed to improve the efficacy of protein removal from fresh natural rubber latex (NRL) and to decrease the production cost by using surfactant treatment and leaching combination processes. The 0.5-3% anionic surfactants, i.e. sodium dodecyl sulfate or sodium lauryl ether sulfate, nonionic tween80 surfactant, or an amphoteric cocamidopropyl betaine surfactant was used in surfactant treatment process. Moreover, water, aqueous surfactant solutions, and/or 1-5% organic solvents (i.e. ethanol, isopropanol and/or acetone) was then used in leaching process. The fresh NRL was preserved by paraben compounds in the presence of surfactant at ambient temperature for 20-120 minutes, and then centrifuged. This might prevent the skin irritation of deproteinized NRL (DNRL) caused by ammonium stabilizer that normally uses in latex industry. The upper rubber mass was then leached for upto three cycles with leaching solvents, and then finally redispersed in distilled water. The milky-like DNRLs were obtained by these processes. Their dry rubber contents were 41-47% that could be adjusted. Their viscosities were 9-13 centipoises with the pH of 6.04-6.61. The protein residues in these DNRLs were 0.0000-0.3244% which were lower than that of fresh NRL (1.2428%). These indicated the efficacy of studied deproteinization process for 73.90-100.0%. Types and concentrations of surfactant, incubation times, leaching solvents, and cycles of leaching process affected the efficacy of deproteinization process. Moreover, the properties of these dried films were not different from that of fresh NR film. This DNRL could be further used for several applications including medical skin products.

The Effect of Pre-Vulcanization Temperature on Mechanical and Rheological Properties of Starch Filled Natural Rubber Latex Compounds

2013 ◽  
Vol 858 ◽  
pp. 184-189
Author(s):  
Siti Rohana Yahya ◽  
Farah Nadiah Hamdan ◽  
Azura A. Rashid ◽  
Baharin Azahari
Keyword(s):  
Natural Rubber ◽  
Rheological Properties ◽  
Room Temperature ◽  
Natural Rubber Latex ◽  
Shear Thickening ◽  
Filler Loading ◽  
Latex Films ◽  
Rubber Latex ◽  
Thickening Behavior ◽  
Vulcanization Process

The main objective of this study was to investigate the effect of the pre-vulcanization temperature on mechanical and rheological properties of starch filled natural rubber (NR) latex films. The 10 phr filler loading of starch was added into the latex prior to the pre-vulcanization process at 60°C to 140°C. The dipped films were cured in the oven at 100°C for 20 minutes and cooled at room temperature for 24 hours before stripping. The rheological properties of NR latex compounds were studied based on the viscosity measurement. The tensile and tear tests of starch filled NR latex films were also carried out. The results indicated that the rheological properties of the latex compounds showed shear thickening behavior where viscosity was increased with the increase in shear rate and pre-vulcanization temperature proportionally. The pre-vulcanization temperature at 80°C showed the optimum mechanical properties of starch filled NR latex films.

REMOVING EXTRACTABLE PROTEINS IN NATURAL RUBBER LATEX BY CALCIUM CHLORIDE FROM CHICKEN EGGSHELLS

2011 ◽  
Vol 84 (4) ◽  
pp. 543-564 ◽  
Author(s):  
Nuchnapa Tangboriboon ◽  
Prapapan Phudkrachang ◽  
Ruksapong Kunanuruksapong ◽  
Anuvat Sirivat
Keyword(s):  
Natural Rubber ◽  
Calcium Chloride ◽  
Electrostatic Interactions ◽  
Sodium Dodecyl ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Latex Film ◽  
Rubber Latex ◽  
Skin Contact ◽  
Extractable Protein

Abstract Controlling the level of the extractable protein contents in a natural rubber latex is important to the sensitization of natural rubber latex products users. Allergies caused by latex products cause a serious problem in which the sweat removes proteins and allowing a skin contact causing allergic reactions. Calcium oxide from calcined chicken eggshells at 900 °C for 1 h was dissolved in 2M HCl (CaCl2) and used as the thickening agent in which it can modify the protein structure. The eggshells were characterized by the particle size analysis, the impedance analysis, simultaneous thermal analysis (STA), x-ray diffraction (XRD), and Fourier transform infrared spectra (FTIR). Calcium chloride (CaCl2) interacts with the protein molecules and the solvent ions through the hydrogen bonding and the electrostatic interactions driving the extractable protein toward the film surface. Sodium dodecyl sulphate was used as the stabilizer in the natural rubber latex film formation. The extractable protein contents were measured and determined by the modified Lowry method. The concentrated latex samples were further characterized by FTIR, scanning electron microscope, and XRD and the results were reported here. Moreover, near infrared was used to measure the extractable protein spectra of the concentrated latex compounds in the region of 1100–2500 nm.

scholarly journals ADJUSTING THE LOW MOLECULAR WEIGHT OF HYDROXYETHYL CELLULOSE AND APPLIED TO EXTRACT PROTEINS IN NATURAL RUBBER LATEX

2021 ◽  
Vol 59 (5) ◽  
Author(s):  
Lai Thi Kim Dung ◽  
Le Nghiem Anh Tuan ◽  
Bui Duy Du
Keyword(s):  
Natural Rubber ◽  
Protein Content ◽  
Natural Rubber Latex ◽  
Hydroxyethyl Cellulose ◽  
Low Molecular Weight ◽  
Rubber Latex ◽  
H2o2 Treatment ◽  
Medical Products ◽  
Low Protein ◽  
Allergenic Proteins

Natural rubber latex (NRL) with “low protein content” is regarded as less allergenic latex for medical gloves, medical products, condoms, etc. Therefore, this study was conducted to strengthen the fundamental approach of making “low protein NRL” via oligosaccharide hydroxyl ethyl cellulose (oligoHEC) treatment. OligoHEC (Mw ~10,000 g/mol) is degradation product of HEC (Mw ~90,000 g/mol) by 1.5% H2O2 treatment combined with hydrothermal at temperature for 30 minutes at 121°C, pressurized rate of 0.38 mPa by autoclave equipment. OligoHECs were employed to form electrical bonds with the proteins. The target of this study is protein content of NRL ≤ 50 µg/g of rubber, we surveyed the effect of oligoHEC treatment towards the solution proteins content of NRL. Results show that oligoHEC at low concentration (0.25%) effectively extracted the proteins molecules. Interestingly, allergenic proteins content of NRL serum was decreased proportionally (< 50 µg/g of rubber) with the upsurge of oligoHEC concentration, suggesting deactivation of allergenic. These preliminary results indicate a potential approach to produce low allergenic risk NRL products with adding of oligoHEC

Sign in / Sign up

Export Citation Format

Share Document