scholarly journals Enhancement of the Antibacterial Activity of Natural Rubber Latex Foam by Blending It with Chitin

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1039 ◽  
Author(s):  
Nanxi Zhang ◽  
Hui Cao
Keyword(s):  
Antibacterial Activity ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Inhibition Zone ◽  
Rubber Latex ◽  
Culture Dish ◽  
Elongation At Break ◽  
E Coli ◽  
Chitin Content ◽  
Foaming Process

To enhance the antibacterial activity of natural rubber latex foam (NRLF), chitin was added during the foaming process in amounts of 1–5 phr (per hundred rubber) to prepare an environmentally friendly antibacterial NRLF composite. In this research, NRLF was synthesized by the Dunlop method. The swelling, density, hardness, tensile strength, elongation at break, compressive strength and antibacterial activity of the NRLFs were characterized. FTIR and microscopy were used to evaluate the chemical composition and microstructure of the NRLFs. The mechanical properties and antibacterial activity of the NRLF composites were tested and compared with those of pure NRLF. The antibacterial activity was observed by the inhibition zone against E. coli. NRLF composite samples were embedded in a medium before solidification. The experimental results of the inhibition zone indicated that with increasing chitin content, the antibacterial activity of the NRLF composites increased. When the chitin content reached 5 phr, the NRLF composite formed a large and clear inhibition zone in the culture dish. Moreover, the NRLF–5 phr chitin composite improved the antibacterial activity to 281.3% of that of pure NRLF against E. coli.

scholarly journals Chitosan and Natural Rubber Latex Biocomposite Prepared by Incorporating Negatively Charged Chitosan Dispersion

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2777
Author(s):  
Siwarote Boonrasri ◽  
Pongdhorn Sae–Oui ◽  
Pornchai Rachtanapun
Keyword(s):  
Natural Rubber ◽  
Ball Mill ◽  
Negative Charge ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Opposite Trend ◽  
Biocomposite Films ◽  
Mixing Method ◽  
Biocomposite Film

Generally, natural rubber/chitosan (NR/CT) biocomposites could be prepared by either mixing natural rubber latex (NRL) with CT acid solution or mixing dry NR with CT powder on mixing equipment. In the present work, a new mixing method has been proposed and properties of the obtained NR/CT biocomposites are investigated. CT particles were prepared to have a negative charge that could be dispersed in water by using a ball mill before mixing with NRL. The effects of CT loading varied from 0 to 8 phr on latex properties and physical properties of NR/CT biocomposite films were focused. The results showed that the viscosity of NRL increased with increasing CT loading. With increasing CT loading from 0 to 8 phr, 300% modulus of the NR/CT biocomposite film increased, whereas the opposite trend was found for elongation at break. Additionally, the presence of CT in the biocomposite resulted in an increased elastic modulus (E’) in conjunction with enhanced antibacterial activity against Staphylococcus aureus (S. aureus).

Preparation and Properties of Acidified Prevulcanized Natural Rubber Latex

2014 ◽  
Vol 997 ◽  
pp. 239-242
Author(s):  
Guang Lu ◽  
He Ping Yu ◽  
Yong Zhou Wang ◽  
Yong Yue Luo ◽  
Zong Qiang Zeng
Keyword(s):  
Tensile Strength ◽  
Acetic Acid ◽  
Natural Rubber ◽  
Acid Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Acetic Acid Content ◽  
Hot Air ◽  
Aging Resistance

After a maturation of three days at ambient temperature, the sulfur-prevulcanized natural rubber latex (SNRL) was stabilized by 20wt% Peregal O, and then acidified with the 36wt% acetic acid by a ratio of 5, 15, 25, 35 and 45 g of 36wt% acetic acid to 100g SNRL, to obtain acidified prevulcanized NR latex (ASNRL) with different acidity, respectively. The viscosity of ASNRL increased, while the nitrogen content decreased, with the increment of acetic acid content and the decrease in pH; for unaged samples, the tensile strength, elongation at break, 300% and 500% moduli of the ASNRL films were only slightly lower than those of SNRL film; however the hot-air aging resistance decreased with the increment of acetic acid content.

scholarly journals Antibacterial Nanocomposites Based on Fe3O4–Ag Hybrid Nanoparticles and Natural Rubber-Polyethylene Blends

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Thanh Dung Ngo ◽  
Thi My Hanh Le ◽  
The Huu Nguyen ◽  
Thien Vuong Nguyen ◽  
Tuan Anh Nguyen ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Natural Rubber ◽  
Antibacterial Activities ◽  
Hybrid Nanoparticles ◽  
Growth Phases ◽  
Elongation At Break ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Polyethylene Blends ◽  
Internal Mixer

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions.

Anti-Microbial and Self-Cleaning of Natural Rubber Latex Gloves by Adding Mangosteen Peel Powder

2018 ◽  
Vol 777 ◽  
pp. 3-7 ◽  
Author(s):  
Wasan Moopayuk ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Latex Film ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Latex Glove ◽  
Latex Gloves ◽  
Mangosteen Peel

Mangosteen peel powder is one of the most important bio-antioxidants. Adding mangosteen peel powder as filler into natural rubber latex compound for latex glove film formation via dipping process can help the green anti-microbial properties. The physical (smoothness and thickness of film) and mechanical properties (tensile strength and elongation at break) of latex film are still good. Therefore, adding mangosteen peel powder into natural rubber latex gloves can reduce the anti-allergic and antimicrobial on the film surface. Mangosteen peel powder ground by rapid mill is fine particle and high surface area 2.4216 m2/g suitable for homogeneous and compatible for adding into natural rubber latex compound. Ceramic hand mold was dipped into the Ca (NO3)2 coagulant only 3 seconds, then dipped into the natural rubber latex compounds added mangosteen peel powder for 15 seconds, withdrawn hand mold slowly, cured in the oven at 120°C for 30 min, then dried at room temperature, and casted it off the hand mold. The obtained natural latex glove films added mangosteen peel powder are smooth, clear, and thin film surface, the highest elongation at break 803.2711 ± 31.6477%, good tensile strength 30.2933 ± 6.0218 MPa, dense film without water leakage, and good contact angle.

BIO-CACO3 FROM RAW EGGSHELL AS ADDITIVE IN NATURAL RUBBER LATEX GLOVE FILMS

2019 ◽  
Vol 92 (3) ◽  
pp. 558-577
Author(s):  
Nuchnapa Tangboriboon ◽  
Rujika Takkire ◽  
Watchara Sangwan ◽  
Sairung Changkhamchom ◽  
Anuvat Sirivat
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Protein Content ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Latex Glove ◽  
Low Protein

ABSTRACT Raw hen eggshell powder, a calcium carbonate source, was used as a biofiller in the natural rubber latex compound and latex glove film formation via dipping process. The powder was anticipated to improve the physical (smoothness and thickness of film) and mechanical properties (tensile strength and elongation at break) of latex film and to reduce the extractable protein content on film surface. Eggshell powder ground by a rapid mill was fine particles of approximately 37.48 μm in diameter, suitable for homogeneous and compatible addition into the natural rubber latex compound. Dipping hand mold into the natural rubber latex compound with 50 wt% eggshell added was the best formula to obtain a smooth, clear, thin film surface, with the tensile strength of 23.24 ± 0.745 MPa and the highest elongation at break of 723.99 ± 14.60%, along with a low protein content, a dense film without water leakage, and with a good contact angle. The natural rubber latex glove film possessed good physical-mechanical properties and a low protein content as the results of the raw eggshell powder added as a biofiller.

Preparation Polyisoprene (NR) and Polyacrylonitrile Rubber Latex Glove Films by Dipping Ceramic Hand Molds Process and their Properties

2018 ◽  
Vol 382 ◽  
pp. 21-25 ◽  
Author(s):  
Puwitoo Sornsanee ◽  
Vichasharn Jitprarop ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Latex Glove ◽  
Bone China ◽  
Synthetic Rubber ◽  
High Flexibility

Both synthetic and natural rubber latex can be used to form rubber latex glove films for medical and dental applications. The objective in this research is to study the natural and synthetic rubber latex glove films formation by dipping process with the bone china ceramic hand molds for 5, 10, and 15 min. From the experimental, the obtained natural rubber latex glove films are good appearance and good physical-mechanical properties i.e. smooth film surface, light pale yellow color, soft, translucent, high tensile strength, high elongation at break, and high flexibility better than those of synthetic rubber latex glove films. When the dipping time of bone china hand mold into natural rubber latex compound increases effect to tensile strength, thickness, and elongation at break increase. Tensile strength, elongation at break, and tensile stress of natural rubber latex films dipped for 15 min are equal to 12.82 ± 1.19 MPa, 1090.91 ± 4.92%, and 39.23 ± 3.63 N, respectively.

Effect of Latex Treatment on Properties of WNRL/PS Blends

2012 ◽  
Vol 488-489 ◽  
pp. 478-482 ◽  
Author(s):  
Orathai Boondamnoen ◽  
A. Rashid Azura ◽  
Masahiro Ohshima ◽  
Saowaroj Chuayjuljit ◽  
Azlan B. Ariffin
Keyword(s):  
Fracture Surface ◽  
Natural Rubber ◽  
Complex Modulus ◽  
Natural Rubber Latex ◽  
Tensile Fracture ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Tensile Fracture Surface ◽  
Sem Micrograph ◽  
Internal Mixer

The waste natural rubber latex was treated with natural rubber latex (TWNRL) prior to blend with polystyrene (PS). The blend was conducted with the ratio of 30/70, 50/50 and 70/30 TWNRL/PS using Haake internal mixer at 140 °C and 60 rpm. The waste natural rubber latex/PS (WNRL/PS) was prepared in the similar procedure. The complex modulus (E*) at various temperature and tensile properties were investigate. The tensile fracture surface was observed using Scanning Electron Microscope (SEM). The results show that the E* of WNRL/PS blends are higher at any temperature compared to TWNRL/PS blend for similar compositiondue to higher network molecules. At 30/70 blends show the tensile strength, Young’s modulus and elongation at break of TWNRL/PS are higher than WNRL/PS blend due to a better molecule entanglement. Improvement of elongation at break was shown for70/30 TWNRL/PS blend, because of the rearrangement of molecule chains under stress. The SEM observation show the successful improvement of blend morphologies by latex treatment at all composition. Moreover, the SEM micrograph also imply the fracture behavior; more tendril on fracture surface indicating the higher strain needed before failure.

Effect of Aging on Mechanical Properties of Natural Rubber Latex Products Filled with Alkanolamide-Modified Cassava Peel Waste Powder (CPWP)

2015 ◽  
Vol 1123 ◽  
pp. 387-390 ◽  
Author(s):  
Hamidah Harahap ◽  
Adrian Hartanto ◽  
Kelvin Hadinatan ◽  
Indra Surya ◽  
Baharin Azahari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Hot Air ◽  
Before And After ◽  
Cassava Peel

The effect of aging on mechanical properties of natural rubber latex (NRL) products filled with alkanolamide-modified cassava peel waste powder (CPWP) was studied. CPWP used as fillers was prepared by milling and sieving it until the size of 100 mesh. The powder then was dispersed in a suspension containing water and alkanolamide in order to modify the prepared powders. The dispersion system of 10 pphr (part per hundred rubber) then was added into NRL matrix followed by pre-vulcanization at 70°C for 10 minutes. The NRL compound then were casted into films by coagulant dipping method then dried at 120°C for 10 minutes. Afterwards, the films were allowed to cool at room temperature for 24 hours before being aged in a circulation of hot air for 24 hours at 70°C. The properties such as tensile strength, tensile modulus, and elongation at break were evaluated between the aged samples and the unaged samples. From this study, it showed that the aged films have increasing value of tensile strength and tensile modulus while the value of elongation at break decreases. These datas are supported by Scanning Electron Microscope (SEM) micrographs which indicate that the change of morphology in NRL films occurs before and after aging.

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