scholarly journals Graft Copolymerization of Methyl Methacrylate and Vinyltriethoxysilane onto Natural Rubber

2021 ◽  
Vol 31 (4) ◽  
pp. 55-60
Keyword(s):  
Nmr Spectroscopy ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Tensile Property ◽  
Graft Copolymer ◽  
Graft Copolymerization ◽  
Silica Particles ◽  
Grafting Efficiency

Preparation and characterization of natural rubber grafted with methyl methacrylate (MMA) and vinytriethoxysilane (VTES) were performed in the present work. Graft copolymerization of methyl methacryate was carried out in latex stage, and VTES was added during the graft copolymerization of MMA. FTIR and NMR spectroscopy were used to investigate the structure of graft copolymer and determination of conversion and grafting efficiency of MMA. It confirmed that the poly(methyl methacrylate) (PMMA) and silica particles (PVTES) were successfully formed in NR-graft-PMMA-PVTES graft copolymer. Conversions of MMA were about 90-100%; however, MMA grafting efficiency decreased as the MMA concentrations increased. Tensile property of NR-graft-PMMA-PVTES was found to improve compared with that of pure NR.

scholarly journals Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Thi Nhan Nguyen ◽  
Hieu Nguyen Duy ◽  
Dung Tran Anh ◽  
Thuong Nghiem Thi ◽  
Thu Ha Nguyen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Graft Copolymer ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Thermal And Mechanical Properties ◽  
H Nmr ◽  
Tert Butyl Hydroperoxide ◽  
Deproteinized Natural Rubber

In this study, we investigated the improvement of the thermal and mechanical properties of Vietnam deproteinized natural rubber (DPNR) via graft copolymerization of methyl methacrylate (MMA). The graft copolymerization was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) and tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds and initiator concentration of 6.6×10−5 mol/g-rubber, the highest grafting efficiency and conversion were achieved at MMA of 15 wt.% per kg of rubber, 68% and 90%, respectively. The structure of grafted copolymers was characterized by 1H NMR, FTIR-ATR, and GPC, and thermal properties were investigated through DSC and TGA measurements. These showed that graft copolymers were more stable and rigid than DPNR. Storage modulus (G′) of graft copolymer was found to double that of DPNR, which contributed to the formation of graft copolymer. After sulfur vulcanization, the mechanical properties of DPNR-graft-PMMA, such as tensile strength, tear strength, and hardness, were improved significantly. Curing behaviors of the graft copolymers were found to be remarkably better than virgin DPNR.

Graft Copolymerization of Methyl Methacrylate onto Natural Rubber by Microwave Irradiation

2010 ◽  
Vol 93-94 ◽  
pp. 39-42
Author(s):  
Sirichai Piyaauksornsak ◽  
Boonchoat Paosawatyanyong ◽  
Napida Hinchiranan
Keyword(s):  
Energy Consumption ◽  
Reaction Time ◽  
Nmr Spectroscopy ◽  
Microwave Irradiation ◽  
Chemical Modification ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
1H Nmr Spectroscopy ◽  
Graft Copolymerization ◽  
Initiation System

The graft copolymerization is one chemical modification methods to improve natural rubber (NR)’s properties via both solution and latex phases. To enhance the polarity of NR, methyl methacrylate (MMA) was applied for graft copolymerization of NR in the presence of thermal or redox initiators. However, the conventional graft copolymerization generally spends long reaction time (ca. 6-8 h). Due to less energy consumption with faster heating rate, the microwave irradiation was used to induce graft copolmerization of MMA onto NR latex using redox initiation system. By comparing with the conventional grafting method at the same grafting properties, the graft copolymerization of MMA onto NR induced by microwave at 100 W spent the shorter reaction time ca. 15 min; whilst, the conventional method required the longer reaction time as 7 h. The influence of microwave power on the grafting properties was investigated. The structure of graft product was also analyzed by using FTIR and 1H NMR spectroscopy.

Graft copolymerization of methyl methacrylate and vinyltriethoxysilane binary monomers onto natural rubber

2021 ◽  
Vol 28 (7) ◽  
Author(s):  
Thuong Nghiem Thi ◽  
Ha Cao Hong ◽  
Yusof Nurul Hayati ◽  
Seiichi Kawahara
Keyword(s):  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Graft Copolymerization

scholarly journals Dynamic Mechanical Properties of Vietnam Modified Natural Rubber via Grafting with Styrene

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
T. A. Dung ◽  
N. T. Nhan ◽  
N. T. Thuong ◽  
D. Q. Viet ◽  
N. H. Tung ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Graft Copolymer ◽  
Graft Copolymerization ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Tert Butyl Hydroperoxide ◽  
Wide Range ◽  
Redox Initiator ◽  
Tetraethylene Pentamine

The dynamic mechanical behavior of modified deproteinized natural rubber (DPNR) prepared by graft copolymerization with various styrene contents was investigated at a wide range of temperatures. Graft copolymerization of styrene onto DPNR was performed in latex stage using tert-butyl hydroperoxide (TBHPO) and tetraethylene pentamine (TEPA) as redox initiator. The mechanical properties were measured by tensile test and the viscoelastic properties of the resulting graft copolymers at wide range of temperature and frequency were investigated. It was found that the tensile strength depends on the grafted polystyrene; meanwhile the dynamic mechanical properties of the modification of DPNR meaningfully improved with the increasing of both homopolystyrene and grafted polystyrene compared to DPNR. The dynamic mechanical properties of graft copolymer over a large time scale were studied by constructing the master curves. The value of bT has been used to prove the energetic and entropic elasticity of the graft copolymer.

Structural Characterization of Filled Vulcanizates Part 1. Determination of the Concentration of Chemical Crosslinks in Natural Rubber Vulcanizates Containing High Abrasion Furnace Black

1967 ◽  
Vol 40 (3) ◽  
pp. 866-882 ◽  
Author(s):  
M. Porter
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Volume Fraction ◽  
Exponential Relationship ◽  
Furnace Black ◽  
Simple Linear Relationship ◽  
Chemical Crosslinks ◽  
Natural Rubber Vulcanizates

Abstract The degree to which HAF black restricts the swelling of natural rubber vulcanizates in n-decane has been determined using a vulcanizing system in which the stoichiometry of crosslinking is unaffected by the carbon black. The dependence of the degree of restriction, as measured by the ratio of the volume fractions of rubber in the filled and unfilled vulcanizates swollen to equilibrium, on the concentration of carbon black follows an exponential relationship previously proposed by Lorenz and Parks. This is found to be equivalent to a simple linear relationship between the apparent and actual crosslink concentrations: napparent/nactual=1+Kϕ, where K is a constant characteristic of the filler and φ is its volume fraction in the vulcanizate. The relation has been used to determine actual crosslink concentrations in filled natural rubber vulcanizates. HAF black is found to cause increases of up to 25 per cent in the yield of polymer to polymer crosslinks in conventional sulfur vulcanizing systems, accompanied by changes in rate of cure and of crosslink reversion. All these are small compared with the effect of the filler on many physical properties.

Preparation and Characterization of Epoxidized-30% Poly(methyl methacrylate)-grafted Natural Rubber Polymer Electrolyte

2014 ◽  
Vol 28 ◽  
pp. 163-170 ◽  
Author(s):  
Khuzaimah Nazir ◽  
Siti Fadzilah Ayub ◽  
Ahmad Fairoz Aziz ◽  
Ab Malik Marwan Ali ◽  
Muhd Zu Azhan Yahya
Keyword(s):  
Ionic Conductivity ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Room Temperature ◽  
Ionic Conduction ◽  
Lithium Triflate ◽  
Poly Methyl Methacrylate ◽  
Order Of Magnitude ◽  
Cast Technique

In this study, a freestanding thin film composed of lithium triflate (LiTf) salt (30-40 wt.%) and epoxidized-30% poly (methyl methacrylate)-grafted natural rubber (EMG30) (50, 54.6, 62.3 mol %) were prepared by a solvent cast technique. The EMG30 were found to increase the ionic conductivity of EMG30-LiTf by one order of magnitude compared to MG30-LiTf. The highest ionic conductivity achieved was 5.584 x10-3Scm-1at room temperature when 40 wt.% of LiTf salts were introduced into 62.3 mol % EMG30. The ionic conduction mechanisms in EMG30-LiTf electrolytes obey Arrhenius rule in which the ion transport in these materials is thermally assisted.

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