Effect of Co-Surfactants and Pasteurization for Preservation of Natural Rubber

This research was a study of the effect of addition linear alkylbenzene sulfonates (LAS), NaHCO3, and NaCl and pasteurization on the preservation of natural rubber (NR). The samples were collected from rubber plantations of Chiang Rai province which were added with three surfactants in samples already. Physical and chemical properties were evaluated using pH, deterioration, viscosity, color, and odor. Then, the samples were stored at 28-30°C periods times of 0, 15, 30, 45, and 60 days. The experiment found that the color, viscosity, odor, and texture of NR samples were not spoiled after being preserved for 30 days but after 45 and 60 days found some coagulation of NR. In the case of non-preserved NR was found that spoiled NR in every period time range of 15-60 days. The pH testing found that increasing period times affect decreased pH value and increased viscosity due to salt of sulfate, carbonate, chloride, and thermal treatment of pasteurization which kill microorganisms and evaporated water. It concluded that the reagents were the process of cosurfactants with heat and frozen for increased effectiveness of anti-acid-producing bacteria and can use as short and long-term preservation of NR under the planting area condition of Thailand.

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Assessment of Graphene Oxide and Nanoclay Based Hybrid Filler in Chlorobutyl-Natural Rubber Blend for Advanced Gas Barrier Applications

Nanomaterials ◽

10.3390/nano11051098 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1098

Author(s):

Jibin Keloth Paduvilan ◽

Prajitha Velayudhan ◽

Ashin Amanulla ◽

Hanna Joseph Maria ◽

Allisson Saiter-Fourcin ◽

...

Keyword(s):

Graphene Oxide ◽

Carbon Black ◽

Natural Rubber ◽

Gas Permeability ◽

Chemical Properties ◽

Barrier Properties ◽

Hybrid Filler ◽

Physical And Chemical ◽

Chlorobutyl Rubber ◽

And Chemical Properties

Nanomaterials have engaged response from the scientific world in recent decades due to their exceptional physical and chemical properties counter to their bulk. They have been widely used in a polymer matrix to improve mechanical, thermal, barrier, electronic and chemical properties. In rubber nanocomposites, nanofillers dispersion and the interfacial adhesion between polymer and fillers influences the composites factual properties. In the present work, a comparison of the hybrid effects of carbon black with two different nanofillers (graphene oxide and nanoclay) was studied. The 70/30 composition of chlorobutyl rubber/natural rubber elastomer blend was taken as per the blend composition optimized from our previous studies. The hybrid effects of graphene oxide and nanoclay in dispersing the nanofillers were studied mainly by analyzing nanocomposite barrier properties. The results confirm that the combined effect of carbon black with graphene oxide and nanoclay could create hybrid effects in decreasing the gas permeability. The prepared nanocomposites which partially replace the expensive chlorobutyl rubber can be used for tyre inner liner application. Additionally, the reduction in the amount of carbon black in the nanocomposite can be an added advantage of considering the environmental and economic factors.

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Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

Journal of Hydrology and Hydromechanics ◽

10.1515/johh-2015-0010 ◽

2015 ◽

Vol 63 (1) ◽

pp. 47-54 ◽

Cited By ~ 23

Author(s):

Karsten Schacht ◽

Bernd Marschner

Keyword(s):

Hydraulic Conductivity ◽

Chemical Properties ◽

Aggregate Stability ◽

Treated Wastewater ◽

Soil Aggregate Stability ◽

Irrigation Effects ◽

Physical And Chemical ◽

The Impact

Abstract The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties.

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Soil physical and chemical properties affected by long-term grazing on the desert steppe of Inner Mongolia, China

CATENA ◽

10.1016/j.catena.2021.105996 ◽

2022 ◽

Vol 211 ◽

pp. 105996

Author(s):

Yujie Dai ◽

Jianying Guo ◽

Yongqiang Li ◽

Zhi Dong ◽

Hongli Li

Keyword(s):

Inner Mongolia ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Desert Steppe ◽

Physical And Chemical ◽

And Chemical Properties

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STUDY OF AMINO ACID MODIFIERS IN GUAYULE NATURAL RUBBER

Rubber Chemistry and Technology ◽

10.5254/rct.15.85931 ◽

2015 ◽

Vol 88 (2) ◽

pp. 310-323 ◽

Cited By ~ 1

Author(s):

Colleen McMahan ◽

Dhondup Lhamo

Keyword(s):

Amino Acids ◽

Natural Rubber ◽

Oxidative Stability ◽

Chemical Properties ◽

The United States ◽

Thermal Oxidative Stability ◽

Green Strength ◽

Strain Induced Crystallization ◽

New Perspective ◽

Physical And Chemical

ABSTRACT Guayule, a desert shrub indigenous to the United States, is under development as a source of natural rubber that can be used in place of petroleum-based rubber or Hevea rubber. In natural rubbers, physical and chemical properties can be strongly affected by nonrubber constituents, typically proteins and lipids, present in the material, depending on the plant species and postharvest processing. Hevea natural rubber typically contains high levels of nonrubber constituents that contribute to thermal-oxidative stability, cure acceleration, and especially strain-induced crystallization. The latter has been attributed to compound properties that render Hevea natural rubber uniquely suited for the most demanding rubber applications (e.g., aircraft tires). Hevea proteins are susceptible to hydrolysis, releasing free amino acids into the latex, which can affect rubber and compound properties. Here, low-protein guayule latex was blended with a series of amino acids varying in chemical structure. Bulk viscosity was reduced, thermal-oxidative stability was improved, and cure rate was influenced by the addition of amino acids. Generally, gel formation, green strength, and tensile strength were not affected. The results introduce a new perspective for amino acids as biobased rubber compound additives and provide insights into naturally occurring nonrubber constituents' interaction with natural rubber polymers.

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Role of trade in natural rubber and palm oil in the composition of GDP in Ivory Coast

Agricultural and Resource Economics: International Scientific E-Journal ◽

10.51599/are.2020.06.03.03 ◽

2020 ◽

pp. 48-63

Author(s):

Paul-Alfred Kouakou Kouakou

Keyword(s):

Economic Growth ◽

Natural Rubber ◽

World Bank ◽

Palm Oil ◽

Ivory Coast ◽

Ardl Model ◽

Oil Exports ◽

Augmented Dickey Fuller ◽

Short And Long Term

Purpose. This paper discusses the effect of natural rubber and palm oil exports on economic growth in Ivory Coast from 1980 to 2016 using World Bank data. Methodology / approach. The analysis involved the use of Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root tests and the ARDL model. Results. This paper discusses the effect of natural rubber and palm oil exports on economic growth in Ivory Coast from 1980 to 2016 using World Bank data. The analysis involved the use of Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root tests and the ARDL model. The results of the study show that there is a positive and non-significant relationship between natural rubber exports and short-term economic growth. On the other hand, in the long term, they have a positive and significant influence on economic development. However, in the short and long term, palm oil exports have a positive and significant impact on gross domestic product. Finally, labour, investment and market opening have a positive and significant effect on economic growth in the short and long term respectively. Therefore, the Ivorian government needs to promote good agricultural practices and agricultural financing in order to increase the competitiveness of the Hevea –Oil palm sector. Originality / scientific novelty. Previous studies in natural rubber and palm oil focused mainly on its production, constraints to production and processing. However, very few studies on its effects on economic growth have been done so far. This study fills that gap. It expanded the existing literature and the subject of the causal relationship between natural rubber and palm oil exports and economic growth in Ivory Coast and shed light on required efforts to enhance the production and utilization of natural rubber and palm oil at larger scale to bring economic development in Ivory Coast. At last, the ARDL model is used to address this issue. Practical value / implications. The generated information will be useful to a number of organizations including: research and development, marketers, producers, policy makers, government and non-governmental organizations to assess their activities and improve their mode of operations, to help better guide the design and implementation of policies and strategies. Finally, knowing the existing relationship between natural rubber and palm oil exports and economic growth, together with impediments faced by natural rubber and palm oil exports, the study provides the various ways to improve these exports by increasing exports capacity of local producers. Research on this issue is too important to inform policymakers regarding resource allocation in the natural rubber and palm oil sector to achieve economic growth.

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Evolution of the Reaction and Alteration of Mudstone with Ordinary Portland Cement Leachates: Sequential Flow Experiments and Reactive-Transport Modelling

Minerals ◽

10.3390/min11091026 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1026

Author(s):

Keith Bateman ◽

Shota Murayama ◽

Yuji Hanamachi ◽

James Wilson ◽

Takamasa Seta ◽

...

Keyword(s):

Reactive Transport ◽

Chemical Properties ◽

Reactive Transport Modelling ◽

Transport Modelling ◽

General Sequence ◽

Long Term Performance ◽

Term Performance ◽

Physical And Chemical ◽

Flow Experiments

The construction of a repository for geological disposal of radioactive waste will include the use of cement-based materials. Following closure, groundwater will saturate the repository and the extensive use of cement will result in the development of a highly alkaline porewater, pH > 12.5; this fluid will migrate into and react with the host rock. The chemistry of the fluid will evolve over time, initially high [Na] and [K], evolving to a Ca-rich fluid, and finally returning to the groundwater composition. This evolving chemistry will affect the long-term performance of the repository, altering the physical and chemical properties, including radionuclide behaviour. Understanding these changes forms the basis for predicting the long-term evolution of the repository. This study focused on the determination of the nature and extent of the chemical reaction, as well as the formation and persistence of secondary mineral phases within a mudstone, comparing data from sequential flow experiments with the results of reactive transport modelling. The reaction of the mudstone with the cement leachates resulted in small changes in pH with the precipitation of calcium aluminium silicate hydrate (C-(A-)S-H) phases of varying compositions. As the system evolves, secondary C-(A-)S-H phases re-dissolve and are replaced by secondary carbonates. This general sequence was successfully simulated using reactive transport modelling.

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Dispersion and Intersection of Hydrothermal Plumes in the Manus Back-Arc Basin, Western Pacific

Geofluids ◽

10.1155/2020/4260806 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18

Author(s):

Zhigang Zeng ◽

Xiaoyuan Wang ◽

Bramley J. Murton ◽

Haiyan Qi ◽

Berit Lehrmann ◽

...

Keyword(s):

Water Column ◽

Ph Value ◽

Chemical Properties ◽

Hydrothermal Systems ◽

Pacmanus Hydrothermal Field ◽

Different Depths ◽

Hydrothermal Plumes ◽

Back Arc ◽

Physical And Chemical ◽

Fluid Sources

The composition of hydrothermal plumes reflects the physical and chemical characteristics of seafloor hydrothermal fluids, which in turn reflects the host rock and subseafloor reaction conditions as well as the water column processes that act to alter the plumes as they disperse and age. Here, we show that the turbidity, current, pH value, dissolved Fe (dFe), and dissolved Mn (dMn) compositions of hydrothermal plumes can be used to understand the spatial distribution and source of hydrothermal systems in the submarine geological environment. Data were obtained from 18 hydrocast stations, among which the water column samples were collected at 8 stations during the MANUS cruise of R/V KEXUE in 2015. The results showed that the Satanic Mills plume and Fenway plume rose approximately 140 m and 220 m above the seafloor, respectively. In the Satanic Mills plume, dFe remained longer than dMn during lateral plume dispersal. There was a clear intersection of the Satanic Mills plume and Fenway plume between 1625 m and 1550 m in the PACMANUS hydrothermal field, and the varied dispersion trends of the mixed plumes were affected by current velocities at different depths. The physical and chemical properties of the seawater columns in the Manus Basin were affected by the input of high-Mn, high-Fe, and low-Mg vent fluids. The turbidity and dFe, dMn, and dissolved Mg concentrations in the sections of the plumes proximal to the Satanic Mills, Fenway, and Desmos vent sites were generally higher (turbidity, Mn, and Fe) and lower (Mg) than those in the sections of the plumes that were more distal from the vent sites. This implied that the plumes proximal to their vent fluid sources, which were interpreted to have relatively young ages, dispersed chemically over time, and their concentrations became more similar to those of the plumes that were more distal from their vent fluid sources.

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EFFECT OF PROTEIN ADDITION ON PROPERTIES OF GUAYULE NATURAL RUBBER

Rubber Chemistry and Technology ◽

10.5254/rct.17.83746 ◽

2017 ◽

Vol 90 (2) ◽

pp. 387-404 ◽

Cited By ~ 3

Author(s):

Dhondup Lhamo ◽

Colleen McMahan

Keyword(s):

Amino Acids ◽

Natural Rubber ◽

Oxidative Stability ◽

Chemical Properties ◽

Green Strength ◽

Truck Tires ◽

Oxidative Resistance ◽

Strain Induced Crystallization ◽

General Protein ◽

Physical And Chemical

ABSTRACT Parthenium argentatum, commonly known as guayule, is a desert shrub cultivated as a domestic source of natural rubber in the semi-arid southwestern United States. Guayule natural rubber (GR) may be used to replace petroleum-based rubber or in place of Hevea natural rubber (NR), but substitution must take into consideration differences in physical and chemical properties. Currently, Hevea NR is required in tire applications, especially aircraft and truck tires, because of its high oxidative resistance, rapid cure rate, and exceptional stress–strain response. These outstanding features are attributed to the presence of nonrubber constituents, mainly proteins and lipids, which cause the rubber to gel, and they contribute to strain-induced crystallization. In contrast, GR is low in proteins and is thus deprived of some attributes of Hevea. Addition of amino acids and proteins to guayule could potentially improve performance and thereby widen the range of applications for use. In a previous study, amino acids blended with GR latex improved thermo-oxidative stability, served as plasticizers and cure accelerators, and enhanced green strength slightly, but tensile strength was not improved. Here, a series of bio-based commercial proteins (gelatin, soy, albumin, casein, zein, gliadin, and gluten) were added to GR as a latex blend. In general, protein addition reduced bulk viscosity and improved thermo-oxidative stability. The gel content and green strength of the polymer–protein blends were increased, with the exception of gliadin, but not to levels observed for Hevea. Effects on vulcanization and mechanical properties in compounds were surprisingly influenced by the choice of antioxidants used. Our results demonstrate the potential of proteins as bio-based rubber compounding additives.

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