Effect of Bio-Fibrils Incorporating with TiO2 on the Properties of Natural Rubber Foam

In this study, empty fruit bunch (EFB) was pretreated and bleached with 2.5 M NaOH at 80°C for 8 h and ClNaO for 12 h, respectively. Then it was hydrolyzed in the acid mixture of 5%wt. C2H2O4 and 48%wt. H2SO4 for 24 h. The obtained bio-fibrils and titanium dioxide (TiO2) were filled into the natural rubber latex (NRL) with the help of vulcanizing agent, antioxidant, accelerators, curing agent and gelling agent to get the resulted natural rubber (NR) foams. The morphology properties and physical properties of all foam samples were checked by using scanning electron microscope and universal testing machine, respectively. The properties of EFB fibers and bio-fibrils were also compared. The density of prepared foams was found out. Resulted showed that the bio-fibrils have the smooth surface with smaller size than BFB fibers. Addition of these bio-fibrils and TiO2 particles into NRL latex contributed the significant improvement of density and physical strength of the resulted foams. The composite foam containing 1.0 phr of bio-fibrils and 2.5 phr of TiO2 had the highest value of density and tensile stress.

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Thermal Insulation Performances of Plaster Composites Based on Embedding Natural Rubber Latex Compound

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.904.441 ◽

2021 ◽

Vol 904 ◽

pp. 441-446

Author(s):

Nuchnapa Tangboriboon ◽

Sarun Muntongkaw ◽

Sompratthana Pianklang

Keyword(s):

Natural Rubber ◽

Thermal Insulation ◽

Water Solubility ◽

Testing Machine ◽

Natural Rubber Latex ◽

Cold Weather ◽

Mechanical And Thermal Properties ◽

Rubber Latex ◽

Universal Testing ◽

Cost Of Energy

Adding 0, 20, and 50 wt% natural-rubber latex compound into the plaster ceiling matrix affected to increase the physical-mechanical-thermal performance properties of plaster ceiling composites. Adding 50 wt% natural rubber latex compound into plaster composites can increase the superior adhesion of the nail-tensile resistance equal to 57.54 N and decrease thermal conductivity equal to 0.0634 W/m.K. In addition, adding natural rubber latex compounds into plaster composites can reduce water solubility, brittleness, impact, and cost of energy consumption due to the exterior temperature. Adequate thermal insulation for roofing, ceiling, and wall systems also reduces radiative losses that chill occupants in cold weather, and reduce interior surface temperatures in the summer, thereby optimizing the comfort of building occupants. The mechanical and thermal properties of plaster composites were investigated by using a Universal Testing Machine (UTM) and heat flow meter, respectively, measured according to TIS 1211-50, TIS 219-2522, and ASTM C518.

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INFLUENCE OF THE VOLATILE FATTY ACID CONTENT TO RADIATION VULCANIZED NATURAL RUBBER LATEX (RVNRL)

Periódico Tchê Química ◽

10.52571/ptq.v9.n17.2011.28_periodico17_pgs_28_37.pdf ◽

2012 ◽

Vol 09 (17) ◽

pp. 38-41

Author(s):

Hugo David CHIRINOS ◽

Sueli CARVALHO DE JESUS

Keyword(s):

Fatty Acid ◽

Natural Rubber ◽

Acid Content ◽

Volatile Fatty Acid ◽

Fatty Acid Content ◽

Natural Rubber Latex ◽

Rubber Latex ◽

Protein Layer ◽

Physical Strength ◽

The Stability

Natural rubber latex is a dispersion of natural rubber particles in water. These particles are coated with a protein layer which will stabilize the dispersion in water by forming an electric charge in the layer. Any different condition affecting this layer disturbs the stability of dispersion. Microorganism attack disturbs the protein layer and consequently the stability of the dispersion. By adding 1.2% by weight of NH3, the stability of the dispersion can be improved. The fresh latex was irradiated by Co-60 with irradiation dose of 10, 20, 30, 40 and 100 kGy. The results showed a relationship between the volatile fatty acid content (VFA, product from microorganism attack on carbohydrate) and the green strength or the physical properties of vulcanized film. Low VFA number showing a higher physical strength of the film either un-vulcanized or vulcanized. It appeared that the structure was responsible in yielding a good physical property of the film.

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Comparison of Mechanical Properties between Thai Orthodontic Elastics with Different Ammonia Contents and Commercial Orthodontic Elastics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.378-379.580 ◽

2011 ◽

Vol 378-379 ◽

pp. 580-584

Author(s):

N. Anuwongnukroh ◽

Porntiwa Senarak ◽

Surachai Dechkunakorn ◽

Theeralaksna Suddhasthira ◽

C. Kongkaew ◽

...

Keyword(s):

Mechanical Properties ◽

Natural Rubber ◽

Breaking Strength ◽

Testing Machine ◽

Natural Rubber Latex ◽

Rubber Latex ◽

Maximum Displacement ◽

Significant Difference ◽

Extension Force ◽

Residual Force

Introduction: The most widely used preservative system for natural rubber latex to date is the ammonia-based system preventing spontaneous coagulation and putrefaction due mainly to bacteria contamination. Objectives: The study compared 2 types of Thai orthodontic elastics, produced from natural rubber latex with different ammonia contents with commercial orthodontic elastics in terms of initial extension force, residual force, force loss, swelling index, breaking strength and maximum displacement. Materials and Methods: Thai orthodontic elastics were developed from 2 types of natural rubber latex; low ammonia < 0.15% (Thai-L), and high ammonia not < 0.6% (Thai-H). The mechanical properties of Thai orthodontic elastics were compared with commercial elastics (Ormco). Mechanical properties were tested using a universal testing machine (Instron 5566). Data were analyzed by One-way ANOVA and Tukey’s test compared the measurements among groups. Results: Ormco had the highest initial extension force and showed significant differences with Thai-L and Thai-H. Thai-L had the highest residual force but showed no significant difference compared with Ormco. Thai-L had the lowest percent of force loss and showed significant differences with Thai-H and Ormco. Thai-L had lower force loss than Thai-H. For swelling index, Thai-L had the highest elasticity. For breaking strength and maximum displacement, both Thai elastics met the Australian Standard (AS) for breaking strength and maximum displacement, similar to Ormco elastics. Conclusion: All elastics met the specifications of the AS for breaking strength and maximum displacement. Thai-L had comparable properties with commercial orthodontic elastics in terms of mechanical properties. Thai-L had comparable properties with Ormco in terms of mechanical properties and may be developed for orthodontic purposes.

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Effects of Drying Temperature on the Properties of Deproteinized Natural Rubber Latex/Starch Composite Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.99 ◽

2013 ◽

Vol 747 ◽

pp. 99-102 ◽

Cited By ~ 1

Author(s):

Rungtiwa Waiprib ◽

Prapaporn Boonme ◽

Wiwat Pichayakorn

Keyword(s):

Natural Rubber ◽

Testing Machine ◽

Composite Films ◽

Natural Rubber Latex ◽

Physical And Mechanical Properties ◽

Rice Starch ◽

Surface Films ◽

Rubber Latex ◽

Drying Temperature ◽

Deproteinized Natural Rubber

The aim of this study was to observe the effects of drying temperature on the properties of deproteinized natural rubber latex (DNRL)/starch composite films. These composite films were prepared by simple mixing and then drying at different temperatures of 50, 60 and 70°C. Various parameters such as types (potato, sago, bean, corn, tapioca, rice, and glutinous starches), amounts (5-20 part per hundred of rubber (phr)) and water-dispersed concentrations (5-50%) of starch blended were evaluated. It was found that only some DNRL/starch composite formulations could be prepared as the completely homogeneous films. Drying temperature affected the degree of starch gelatinization that confirmed by differential scanning calorimeter (DSC) technique. The DNRL composite films of 20 phr of all 7 starch types could be formed at 50 and 60°C, while those of 20 phr sago, bean, corn, and rice starch could be formed at 70°C. Some of these films were difficult to be the completely dry films at 70°C due to their more degree of gelatinization of starch on the surface films which inhibited the evaporation of water inside the films. However, only some DNRL/starch composites showed the homogeneous film under cross-section scanning electron microscopy (SEM) observations. Their compatibilities were confirmed by Fourier transform infrared spectroscopy (FT-IR) and DSC. Their physical and mechanical properties were further evaluated by the universal testing machine.

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Fabrication of Novel Polyhydroxybutyrate-co-Hydroxyvalerate (PHBV) Mixed with Natural Rubber Latex

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.659.404 ◽

2015 ◽

Vol 659 ◽

pp. 404-408 ◽

Cited By ~ 3

Author(s):

Karndarthip Kuntanoo ◽

Sarunya Promkotra ◽

Pakawadee Kaewkannetra

Keyword(s):

Mechanical Properties ◽

Natural Rubber ◽

Testing Machine ◽

Natural Rubber Latex ◽

Melting Behavior ◽

Melting Transition ◽

Rubber Latex ◽

Scanning Calorimetry ◽

Wide Range ◽

Mixed Films

Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is mixed with natural rubber latex to make better mechanical properties of PHBV. The various ratios between PHBV and natural rubber latex are examined to improve their mechanical properties. The PHBV are solid, easily broken, while natural rubber is excessive elastic materials. Concentrations of the employed PHBV solution are 1, 2, and 3 (%w/v). The mixtures of this solution to natural rubber latex are fabricated the biofilms in three different ratios, 4:6, 5:5, and 6:4, respectively. The films are characterized by electron microscope, universal testing machine, and differential scanning calorimetry (DSC). The electron micrographs of the mixed films and unmixed PHBV yield the lowest void distributions in 3%w/v PHBV. For mechanical properties, the averaged elastic moduli of 1, 2, and 3 (%w/v PHBV) mixed films are 773, 955 and 1,008 kPa, respectively. Their tensile strengths increase with increasing the PHBV concentrations. A similar trend is also found in elastic modulus. The crystallization and melting behavior of pure PHBV and the mixed films are examined by DSC. Melting transition temperatures of pure PHBV exhibit two melting peaks at 154°C and 173°C. In addition, the melting peaks of the mixed films remain in the range of 152-156°C and 168-171°C, respectively. According to their morphology, void distributions reduce twice, compared to the unmixed PHBV. Mechanical properties and thermal analysis indicate that the mixed PHBV can be improved their properties with more resilient and wide range temperature than usual.

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