Molecular Structure of Natural Rubber and Its Characteristics Based on Recent Evidence

Sakdapipanich, Jitladda; Rojruthai, Porntip

doi:10.5772/29820

Cited by 11 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be deduced that the addition of ethanol in DPNR solution resulted in the decomposition of branchpoints caused by hydrogen bonding between phospholipids and proteins. Sakdapipanich et al [41] studied on the subject of molecular structure of natural rubber and its characteristics based on recent evidence. It was reported that NR contains both soft-gel and hard-gel [56].…”

Section: Effect Of Ethanol On Gel Fraction Of Nr Latex Particlesmentioning

confidence: 99%

Development and characterization of bacterial cellulose/natural rubber composite films

Potivara

View full text Add to dashboard Cite

The composite of bacterial cellulose (BC) and natural rubber (NR) has been developed in this study to combine the prominent properties between strength from three-dimensional structure of BC nanocellulose and flexible molecular chain of isoprene (C5H8). BC membranes were produced by A. xylinum using coconut-water medium under static incubation for 5 days. The BC membrane were then purified and immersed in NR latex solution at various concentrations (0-10 % v/v). The influence immersion temperature (30°C, 50°C, 60°C and 70°C) and a ratio of ethanol in the solvent were also investigated. The results were compared with the unmodified BC. NR particles were characterized by Laser particle size distribution (PSD), the morphology and cross-section of films by Field Emission Scanning Electron Microscopy (FESEM), functional groups and intermolecular interactions by Fourier Transform Infrared Spectroscopy (FTIR), the crystallinity structure by X-ray diffraction (XRD), the thermal properties of composite films by Differential Scanning Calorimetry (DSC), the mechanical properties by Instron testing machine, the water absorption capacity, toluene uptake and biodegradable in soil measurements. According to the experiments, the addition of a certain amount of ethanol slightly affected NR particle size but helped reduce the viscosity of NRL, resulting in more penetration of NR molecules into BC. The optimal condition was the immersion at 2.5–5.0 % NR latex solution, under the temperature of 50-60°C, where the thickness of the composite could be enhanced from ~12 μm of the unmodified BC to ~20-27 μm. The crystallinity structure of the composite films remained as BC structure. The new peak was not occurred from FTIR analysis; however a slight shift of hydroxyl peaks might indicate some weak physical interactions between BC and NR. The results show that the water absorption decreased and the toluene uptake increased as compared to normal BC film. Moreover, the tensile strength and elongation at break of the NR-BC composited films were significantly improved for 3-6 folds in comparison to the normal BC film. The results of biodrgradation in soil showed that the composite films could completely degrade for 5-6 weeks.

show abstract

Section: Effect Of Ethanol On Gel Fraction Of Nr Latex Particlesmentioning

confidence: 99%

Development and characterization of bacterial cellulose/natural rubber composite films

Potivara

View full text Add to dashboard Cite

show abstract

“…The collected latex is treated with formic acid and transfers into a consolidated rubber particle. Then, the solid rubber is pressed into thin crepe sheets and it is called air-dried sheet (ADS) or ribbed smoked sheet (RSS) (Sakdapipanich & Rojruthai, 2012). As a result of proteins and lipids containing in latex, the surface of rubber particles has a negative charge and causes the latex stability.…”

Section: Biochemistry Of Latexmentioning

confidence: 99%

“…There are the transformation of rubber structure, the modification of carbon-carbon double bond and the grafting with different polymer chain. The NR structure is transformed through the addition of acidic reagents, thermal treatment and degradation (Riyajan & Sakdapipanich, 2006;Van Veersen & Technology, 1951) The double bond modification refers to halogenation, hydrogenation and epoxidation reactions (Roberts, 1988) Another modification of NR is grafted with various polymer types such as maleic anhydride (maleinization) and vinyl monomers (graft copolymerization) (Bacon, Farmer, & Technology, 1939). Each technique causes different properties of NR, for instance, the hydrogenation reaction enhanced thermal stability of NR.…”

Section: Chemical Modificationmentioning

confidence: 99%

Application of reduced graphene oxide/ natural rubber composite for petroleum removal in sea water

Songsaeng

View full text Add to dashboard Cite

In this study, the natural rubber (NR) composite foam was prepared to enhance oil adsorption performance of NR foam. The reduced graphene oxide (rGO) was synthesized from graphite waste by oxidation and reduction processes. In the oxidation step, different oxidation conditions (thermal-sonication and stirring-sonication) were studied in order to achieve the highest interlayer spacing in graphite structure. Then, the reduction was carried out using L-ascorbic acid (L-AA) as a reducing agent. Furthermore, morphology and surface properties of the synthesized rGO were investigated. To prepare the NR composite foams, NR latex was mixed with various contents of rGO (0.25, 0.5, 1.0 and 1.5 parts by weight per hundred part of rubber: phr). The results showed that the amount of rGO affected the morphology and the oil adsorption capacity of �NR composite foams. The optimum amount of rGO in the NR composites foam which exhibited the highest oil adsorption performance was 0.5 phr. The oil adsorption capacity of NG-0.5 for gasohol, kerosene, crude oil, diesel and fuel was 21.50, 19.31, 17.04, 16.53 and 10.09 g g-1, respectively. In addition, the effect of temperature and turbulence on the oil adsorption capacity of the NR composite foams was determined. Three kinetic models, i.e. pseudo-first-order, pseudo-second-order and Elovich equation, were examined. The pseudo-second-order presented the better fit with the experimental data. The Langmuir isotherm was an appropriated model to predict the oil adsorption behavior of the NR composite foams. Finally, reusability feature of the NR composite foams was also studied through fifteen oil adsorption-desorption cycles. The result showed that the NR composite foams could be reused in many times.

show abstract

Exploring temperature effects on compatibility in PS‐b‐PI‐b‐PS block copolymer‐based blends through experimental and molecular dynamics simulation approaches

Lazim,

Shamsudin,

Mazlan

et al. 2024

Polymer Engineering & Sci

View full text Add to dashboard Cite

The poly(styrene‐block‐isoprene‐block‐styrene) (PS‐b‐PI‐b‐PS) block copolymer is known for its self‐assembly characteristics and dual structure that combines rubber and thermoplastic materials. Conventionally, blends of block copolymers are fabricated using the melt blending method, a process that requires high temperatures. This study introduces an energy‐efficient solution blending method to enhance the compatibility between PS‐b‐PI‐b‐PS and natural rubber (NR) latex. NR latex was blended with PS‐b‐PI‐b‐PS in toluene at temperatures of 80, 100, 120, and 150°C and cast to form films. The solution‐blended film prepared at a moderate temperature of 120°C exhibited a maximum tensile strength of 9.48 MPa and was thermally degraded at higher temperature (382°C) than those produced by melt blending. The solution blending method also reduced the surface roughness and the particle size to between 7 and 500 nm and improved the interfacial adhesion in SB‐120°C blend compared to MB‐180°C blend. Molecular dynamics simulations indicated that the improved mechanical performance of the blend was primarily due to enhanced intramolecular bonding, with a maximized bond energy of 20,133 kcal/mol. This work demonstrates an energy‐efficient method with lower processing temperature for preparing polymer blends with improved compatibility suitable for various nanotechnology and engineering applications.Highlights Solution blending method improves the compatibility. Tensile strength and interfacial adhesion of the polymer blend improved. Solution blending reduces the particle size and surface roughness. Simulation shows an increase in intramolecular bond energy.

show abstract

Molecular Structure of Natural Rubber and Its Characteristics Based on Recent Evidence

Cited by 11 publications

References 27 publications

Development and characterization of bacterial cellulose/natural rubber composite films

Development and characterization of bacterial cellulose/natural rubber composite films

Application of reduced graphene oxide/ natural rubber composite for petroleum removal in sea water

Exploring temperature effects on compatibility in PS‐b‐PI‐b‐PS block copolymer‐based blends through experimental and molecular dynamics simulation approaches

Contact Info

Product

Resources

About