Effect of Particle Sizes on Film Formation Behavior of Hevea brasiliensis Natural Rubber Latex

2015 ◽  
Vol 659 ◽  
pp. 383-387 ◽  
Author(s):  
Nut Churinthorn ◽  
Adun Nimpaiboon ◽  
Jitladda Sakdapipanich ◽  
Chee Cheong Ho
Keyword(s):  
Particle Size ◽  
Natural Rubber ◽  
Room Temperature ◽  
Storage Time ◽  
Film Formation ◽  
Rubber Particle ◽  
Natural Rubber Latex ◽  
Wide Distribution ◽  
Rubber Particles ◽  
Individual Particles

Natural Rubber (NR) latex obtained from Hevea brasiliensis contains a wide particle size distribution. The aim of this study is to investigate the effect of small rubber particles (SRP) and large rubber particles (LRP) on the characteristics of film formation. The rubber particle with different mean diameters can be separated by centrifugation at various speeds to prepare SRP and LRP latex. The average size of SRP and LRP were characterized by light scattering technique to show that the size of SRP was in the range of 0.20 μm, while that of LRP was larger with the wide distribution. SRP and LRP latex were dried at room temperature to study the film formation behaviors. The results showed that the film compaction time increased with increasing the particle size of NR. Furthermore, the rubber film were aged at room temperature for 3 weeks in order to observe the surface morphology using atomic forced microscopy (AFM) by tapping mode. The AFM images showed that SRP readily formed a coalescence film, while LRP showed individual particles on the surface of film at 24 h of storage time. The surface of both SRP and LRP films was smoother after storage. However, LRP film still showed individual particles on the surface after 3 weeks of storage time.

Current Study on Structural Characterization and Unique Film Formation of Hevea brasiliensis Natural Rubber Latex

2013 ◽  
Vol 844 ◽  
pp. 498-501 ◽  
Author(s):  
Jitladda Sakdapipanich
Keyword(s):  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Film Formation ◽  
Rubber Particle ◽  
Particle Surface ◽  
Natural Rubber Latex ◽  
Force Microscopy ◽  
Latex Glove ◽  
Commercial Source

Hevea brasiliensis natural rubber (NR) latex is a very important commercial source of elastomers. It is not only a source for dry NR rubber but also the feedstock for the latex glove dipping industry. The particles of freshly tapped latex are known to be stabilized by proteins and lipids that come with the latex from the tree. These non-rubbers [, especially proteins and lipids, confer to the rubber and latex excellent properties unsurpassed by any synthetic latex [. Recent structural studies of NR revealed that the NR molecules comprise of 2 trans-isoprene units connected to a long-chain cis-isoprene units. Two terminal groups, referred to as ω and α, have been postulated to link with mono-and di-phosphate groups associated with phospholipids by H-bonding at the α-terminal, whereas the ω-terminal is a dimethylallyl group links to protein by H-bonding [. Although numerous studies have been published on the surface structure of the natural rubber particle [4-, none of these offered a direct in situ visualization of the intact particle surface. This is because of any attempt to remove this surface layer of proteins and lipids results in an immediate destabilization of the latex. The second part focused on the using of Atomic Force Microscopy (AFM) and Confocal Fluorescence microscopy to visualize and delineate the structure of the proteins and lipids layer on the latex particle surface in situ.

Skim and cream natural rubber particles: colloidal properties, coalescence and film formation

2003 ◽  
Vol 268 (2) ◽  
pp. 330-340 ◽  
Author(s):  
Márcia M Rippel ◽  
Lay-Theng Lee ◽  
Carlos A.P Leite ◽  
Fernando Galembeck
Keyword(s):  
Natural Rubber ◽  
Film Formation ◽  
Colloidal Properties ◽  
Rubber Particles

Influence of Rubber Particle Size on Functional Properties of a Composite Material Based on Scrap Tires and a Polymer Binder

2020 ◽  
Vol 850 ◽  
pp. 107-111
Author(s):  
Laimonis Mālers ◽  
Agnija Cirvele
Keyword(s):  
Particle Size ◽  
Composite Material ◽  
Functional Properties ◽  
Material Properties ◽  
Rubber Particle ◽  
Polymer Binder ◽  
Scrap Tires ◽  
Elongation At Break ◽  
Rubber Particles ◽  
Purposeful Selection

Functional properties of composite material based on mechanically grinded scrap tires with different particle size of fractioned crumb and polyurethane type polymer binder were investigated to estimate influence of rubber particles size and content on composite material properties (Shore C hardness, compressive stress at 10 % deformation, tensile strength, elastic modulus and elongation at break, apparent density). Optimization possibilities of composite material consisting of rubber particles with different sizes or fractions were investigated. The obtained results show that variation of composition of the composite material by changing size of rubber granulate have definite influence on selected properties of the material. Purposeful selection and mutual combination of rubber particles size included in material can ensure desirable and predictable mechanical properties of composite material.

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.

Room temperature prevulcanization of natural rubber latex using xanthate

2004 ◽  
Vol 94 (3) ◽  
pp. 1164-1174 ◽  
Author(s):  
K. K. Sasidharan ◽  
Shiny Palaty ◽  
K. S. Gopalakrishnan ◽  
K. E. George ◽  
Rani Joseph
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Natural Rubber Latex ◽  
Rubber Latex

Deproteinized Natural Rubber as Chewing Gum Base for Nicotine Delivery

2013 ◽  
Vol 844 ◽  
pp. 470-473
Author(s):  
Wiwat Pichayakorn ◽  
Prapaporn Boonme ◽  
Wirach Taweepreda
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Natural Rubber Latex ◽  
Sodium Carboxymethylcellulose ◽  
Rubber Latex ◽  
Initial Modulus ◽  
Chewing Gums ◽  
Significant Difference ◽  
Saccharin Sodium ◽  
Deproteinized Natural Rubber

This study aimed to prepare the nicotine chewing gums for smoking cessation using deproteinized natural rubber latex (DNRL) as gum bases due to its highly flexible property. The formulations were produced by the conventional heat melting and kneading methods. The experimental design was used to obtain the optimum 3 gum base formulations. Each formulation composed of olive oil as a plasticizer; sodium carboxymethylcellulose as an adsorbent; xylitol, mannitol and saccharin sodium as sweeteners instead of sugar. Gum base 1 and gum base 2 had the same sweetener amount but gum base 2 had the lower plasticizer amount, while gum base 1 and gum base 3 had the same plasticizer amount but different sweetener amount. Nicotine was added into each 3 gum bases (NCT1-3). The results showed no significant difference of appearance and taste. Their physicochemical properties were as following: pH of 8.45, 8.46, 8.54, hardness of 39.80, 36.28, 33.14 Shore A, initial modulus of 0.090, 1.260, 0.065 MPa, %elongation of 286, 403, 489%, drug content of 63.62, 70.95, 72.70%, and drug release when 500 times for force clamping of 48.72, 45.72, 67.74%, respectively. After storage at room temperature for 1 month, NCT1 and NCT2 showed unchangeable appearance, but NCT3 showed the slightly liquefied film and much sticky due to hygroscopic property of its sweetener. However, all formulations showed the significant reduction of drug amount which should be further improved in their stability properties.

Deformation mechanisms of sub-micrometer thermoplastic vulcanizates obtained by reaction-induced phase separation of miscible poly(ε-caprolactone)/dimethacrylate systems

Soft Matter ◽  
2017 ◽  
Vol 13 (38) ◽  
pp. 6905-6912 ◽  
Author(s):  
Roy l'Abee ◽  
Martin van Duin ◽  
Han Goossens
Keyword(s):  
Particle Size ◽  
Phase Separation ◽  
Deformation Behavior ◽  
Rubber Particle ◽  
Mechanical Deformation ◽  
Deformation Mechanisms ◽  
Chemical Grafting ◽  
Rubber Particles ◽  
Thermoplastic Vulcanizates ◽  
Grafting Onto

The rubber particle size as well as chemical grafting onto the surface of cross-linked rubber particles control the mechanical deformation behavior of sub-μm thermoplastic vulcanizates (TPVs).

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