scholarly journals Reduction of Offensive Odor from Natural Rubber Using Zinc-Modified Bentonite

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Bryan B. Pajarito ◽  
Kayla C. Castañeda ◽  
Sofia Denise M. Jeresano ◽  
Dominique Ann N. Repoquit
Keyword(s):  
Natural Rubber ◽  
Antimicrobial Effect ◽  
Adsorption Properties ◽  
Zinc Salt ◽  
Zinc Ions ◽  
Sulfate Ions ◽  
Modified Bentonite ◽  
Modification Process ◽  
Limited Exchange

Natural bentonite was modified with zinc ions and was used as a filler to reduce the offensive odor from raw natural rubber (NR). Characterization of filler shows the limited exchange of inherent calcium ions and the preferred adsorption of zinc ions on the surface of natural bentonite during modification. The modification process was also accompanied by bassanite formation due to sulfate ions brought by the zinc salt. Zinc-modified bentonite demonstrates an antimicrobial effect against microorganisms that are known to degrade or produce offensive odor from raw NR. Due to its antimicrobial and adsorption properties, zinc-modified bentonite significantly reduces the offensive odor from raw NR at loadings of 2.5–7.5 phr as shown by the olfactometry test. In terms of vulcanization characteristics, the loading of zinc-modified bentonite at 7.5 phr caused a slight decrease in elastic torque and increase in scorch and curing times of NR. The hardness and tensile properties of vulcanized NR are maintained after compounding with zinc-modified bentonite at 7.5 phr.

Preparation and Adsorption Properties of PDMDAAC Modified Bentonite

2011 ◽  
Vol 399-401 ◽  
pp. 1226-1229
Author(s):  
Hong Shao ◽  
Ning Cao ◽  
Da Wei Wang
Keyword(s):  
Adsorption Properties ◽  
Dyeing Wastewater ◽  
X Ray Diffraction ◽  
Modified Bentonite ◽  
Preparation Conditions ◽  
Treatment Agent ◽  
Optimized Conditions ◽  
Decoloration Rate ◽  
Interplanar Space

A novel environmentally friendly water treatment agent was prepared by the natural bentonite and PDMDAAC. The treatment effect of direct black G dyeing wastewater on different preparation conditions was studied. The decoloration rate reached 98.57% under the optimized conditions (cross-linker concentration of 40g/L, M-V of 12 g/L, contact time of 75min, particle size of 0.124mm). The performance characterization of the modified bentonite was observed by means of X-ray diffraction, scanning electron microscopy. The PDMDAAC has entered into the bentonite interplanar space. The adsorption properties of bentonite were improved, which was suitable for the treatment of dyeing wastewater.

scholarly journals Material parametrization of natural rubber based compound and characterization of crack propagation under consideration of dissipative effects

2021 ◽  
Author(s):  
Dan Pornhagen ◽  
Konrad Schneider ◽  
Markus Stommel
Keyword(s):  
Energy Dissipation ◽  
Crack Propagation ◽  
Natural Rubber ◽  
Experimental Tests ◽  
Material Behavior ◽  
Prony Series ◽  
Material Forces ◽  
Cracking Behavior ◽  
Dissipative Effects

AbstractMost concepts to characterize crack propagation were developed for elastic materials. When applying these methods to elastomers, the question is how the inherent energy dissipation of the material affects the cracking behavior. This contribution presents a numerical analysis of crack growth in natural rubber taking energy dissipation due to the visco-elastic material behavior into account. For this purpose, experimental tests were first carried out under different load conditions to parameterize a Prony series as well as a Bergström–Boyce model with the results. The parameterized Prony series was then used to perform numerical investigations with respect to the cracking behavior. Using the FE-software system ANSYS and the concept of material forces, the influence and proportion of the dissipative components were discussed.

Characterization of the trans-structure in the molecular chain structure of natural rubber

2021 ◽  
pp. 131209
Author(s):  
Zechun Li ◽  
Changjin Yang ◽  
Yanchan Wei ◽  
Yuanbing Zhou ◽  
Shuangquan Liao
Keyword(s):  
Natural Rubber ◽  
Chain Structure ◽  
Molecular Chain ◽  
Trans Structure

Adhesion of Vulcanized Rubber Surfaces: Characterization of Unmodified and Electron Beam Modified EPDM Surfaces and Their Co-vulcanization with Natural Rubber

2009 ◽  
Vol 23 (13-14) ◽  
pp. 1763-1786 ◽  
Author(s):  
Ganesh C. Basak ◽  
Abhijit Bandyopadhyay ◽  
Y. K. Bharadwaj ◽  
S. Sabharwal ◽  
Anil K. Bhowmick
Keyword(s):  
Electron Beam ◽  
Natural Rubber ◽  
Vulcanized Rubber

ANTIMICROBIAL AND POWDER CHARACTERIZATION OF HERBAL DENTIFRICES

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (11) ◽  
pp. 39-47
Author(s):  
V. K Sharma ◽  
◽  
B. Mazumder ◽  
P. P. Sharma
Keyword(s):  
Oral Cavity ◽  
Physicochemical Properties ◽  
Antimicrobial Effect ◽  
Physicochemical Characteristics ◽  
Water Soluble ◽  
Particle Rearrangement ◽  
Bulk Volume ◽  
The Impact ◽  
Tapped Density

The consumption of edible products strongly recommends the regular hygiene of oral cavity. Various dental products of allopathic and herbal origin are used as dentifrices. The dentifrices are considered safe and effective in terms of cleansing effect of oral cavity and antimicrobial effect against microbes causing bad smell and diseases such as gingivitis, pyorrhea etc. These characteristics of preparations are basically related to physicochemical properties of ingredients present in their composition and some how on directions of their use. In the present study, the marketed allopathic dentifrices coded as Brand I and II and herbal tooth powders coded as Brand III and IV were selected to analyze the impact of physicochemical properties of incorporated ingredients on their cleansing efficiency. The physicochemical characteristics studied were pH, bulk volume, tapped volume, tapped density, bulk density, true density, porosity, flowability, compressibility, compactability, cohesiveness, dispersability, Carr’s index, Hausner’s ratio, water soluble content, alcohol soluble content, foaming index, particle rearrangement behaviour and particle rearrangement constant. The antimicrobial effect of these powders was studied against Staphylococcus sorbinus, Staphylococcus salivarius and Lactobacillus acidophilus. It was observed that some of the physicochemical properties of all powders were different from each other. Marked antimicrobial effect of tooth powders was observed against pathogens. In all preparations, remarkable foaming index was analyzed that was generally considered responsible for cleansing effect.

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