Effect of potassium persulfate on graft copolymerization and mechanical properties of cassava starch/natural rubber foams

2010 ◽  
Vol 116 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Varaporn Tanrattanakul ◽  
Wannapa Chumeka
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Cassava Starch ◽  
Potassium Persulfate

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.

Influence of Reaction Conditions on the Properties of Nano-matrix Structure Formed by Graft-Copolymerization of Acrylonitrile onto Natural Rubber

2013 ◽  
Vol 844 ◽  
pp. 365-368 ◽  
Author(s):  
Kontapond Prukkaewkanjana ◽  
Seiichi Kawahara ◽  
Jitladda Sakdapipanich
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Matrix Structure ◽  
Oil Resistance ◽  
Wide Range ◽  
Initial Monomer

Natural rubber (NR) is one of the most important agriculture products of Thailand, which is an important material with unique and special characteristics used in wide range of applications such as mechanical properties, excellent strength, and elasticity. However, it is inferior in oil resistance due to the presence of hydrogen and carbon in its structure. This inherent drawback of NR has limited its application in industry. In order to expand the use of NR, this research is interested to improve the oil resistance of NR without loss of outstanding properties by grafting NR with acrylonitrile (AN) monomer to form the nano-matrix structure. The influences of the initial monomer concentration and initial initiator concentration were investigated. These effects on structure, mechanical properties and oil resistance properties were studied by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, tensile machine, and swelling in toluene, respectively. It was found that the tensile strength and oil resistance properties of graft copolymerization of AN onto NR increased with increasing the percentage grafting efficiency of acrylonitrile monomer.

Preparation and Properties of Sponge Rubber Based on Natural Rubber and Cassava Starch

2014 ◽  
Vol 931-932 ◽  
pp. 68-72
Author(s):  
Komsun Temna ◽  
Nitinart Saetung ◽  
Anuwat Saetung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Cassava Starch ◽  
Interfacial Interaction ◽  
Morphological Properties ◽  
Elongation At Break ◽  
Cure Time ◽  
The Difference ◽  
Cure Characteristic

In this work, the sponge rubbers based on cassava starch masterbatch in latex phase with the difference technique (non-gelatinized and gelatinized cassava starch) were preformed. The cassava starch contents from 0 to 70 phr were also studied. The cure characteristic, mechanical and morphological properties were investigated. It was found that the scorch time and cure time were increased with an increasing of cassava starch contents in both techniques. The mechanical properties i.e., tensile strength, elongation at break and tear strength were decreased with an increasing of cassava starch contents, except 500% modulus. However, the sponge based on gelatinized technique gave the better mechanical properties than that of non-gelatinized cassava starch. The SEM micrographs of sponge NR from gelatinized technique were also able to confirm a good interfacial interaction between hydrophilic cassava starch and hydrophobic 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.

A Study on the Graft-Copolymerization of 2-Acryloyloxyethyl Acid Phosphate onto Natural Rubber

2013 ◽  
Vol 844 ◽  
pp. 377-380
Author(s):  
Chadchai Sorarutayangkoor ◽  
Jirapong Boonyasiri ◽  
Jitladda Sakdapipanich
Keyword(s):  
Mechanical Properties ◽  
Fourier Transform ◽  
Reaction Time ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Agricultural Product ◽  
Acid Phosphate ◽  
Ft Ir ◽  
Heat Build Up

Nowadays, natural rubber (NR) is one of the most important agricultural product of Thailand, which is an important substance with special characteristics such as mechanical properties, excellent strength, and low heat build-up. However, NR is non-polarity that limited its application in industry. To expand the use of NR, this research is interested to improve the polarity of NR by grafting NR with 2-acryloyloxyethyl acid phosphate (P-1A(N)) monomer. The influences of the monomer concentration, dry rubber concentration (DRC) and reaction time were investigated. The best condition of the graft co-polymerization was 10% DRC, 20 phr of monomer and 3h of reaction time. NR was successfully grafted with P-1A(N) monomer by using this condition. It can be confirmed by Fourier Transform Infrared spectroscopy (FT-IR).

scholarly journals Pengaruh Rasio Karet Alam Terdeproteinisasi dengan Monomer Vinil terhadap Karakteristik Karet Alam Termoplastik

2016 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Santi Puspitasari ◽  
Emil Budianto ◽  
Dadi Rusadi Maspanger
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Graft Copolymerization ◽  
Plastic Material ◽  
Natural Rubber Latex ◽  
Physical And Mechanical Properties ◽  
Vinyl Monomer ◽  
Thermoplastic Natural Rubber ◽  
Time And Energy

<em>Chemical modification of natural rubber latex by emulsion graft copolymerization with thermoplastic monomer produces thermoplastic natural rubber (TPNR). Ratio composition of natural rubber to thermoplastic monomer determines the TPNR properties. TPNR has good mechanical properties of natural rubber and high processability of plastic material thus enhancing its application in industry. The research, which was conducted at research laboratory of Indonesian Rubber Research Institute, from June to December 2014, aimed to study the effect of the ratio of deproteinized natural rubber (DPNR) latex to vinyl monomer (VM: methyl methacrylate and styrene) on physical and mechanical properties of TPNR produced from batch graft copolymerization. Batch graft copolymerization was conducted at certain ratios of DPNR latex with methyl methacrylate and styrene </em><em>(70:30; 60:40; and 50:50) at (65°C, 5 hours), and subsequently at (70°C, 1 hour)</em>.<em> The result showed that batch technique tend to cause the formation of homopolymer vinyl which also affected the TPNR properties. Visually, the TPNR had white color, hard and brittle texture yet easier to process as shown by low time and energy consumption during compounding. The ratio of DPNR to VM at 70:30 was regarded as the optimum ratio for its balanced properties between elastomeric material of DPNR and thermoplastic material of VM.</em>

Effect of Compatilizers on Morphology and Properties of Natural Rubber/Polyvinyl Alcohol (NR/PVA) Blends

2014 ◽  
Vol 960-961 ◽  
pp. 262-269
Author(s):  
Ke Chen ◽  
Rui Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Elongation At Break ◽  
Latex Compounding ◽  
Thermal Stability Of

The natural rubber/polyvinyl alcohol (NR/PVA) blends containing various compatilizers grafted from NR were prepared using latex compounding techniques. The effects of various compatilizers on the morphology, mechanical properties and thermal behaviors were studied. The interface compatible performance of the blends were greatly improved with the presence of the compatilizers, and the phase dispertion of the blends achieved the best effect under the action of epoxidized natural rubber (ENR). The onset temperature of the thermal decomposition of ENR and graft copolymerization of methyl methacrylate (MMA) onto NR (NR-g-PMMA) increased obviously, but the maleic anhydride grafted onto NR (NR-g-MAH) drop obviously comparing to that of NR. The thermal stability of the blends were inferior to NR. With the presence of ENR, the tensile strength and elongation at break obtained great value which was ascribed the presence of the best phase dispertion, while the tear strength and shore A hardness obtained great value due to the addition of MAH-g-NR.

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