scholarly journals Selectively Etched Halloysite Nanotubes as Performance Booster of Epoxidized Natural Rubber Composites

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3536
Author(s):  
Indra Surya ◽  
Kamaruddin Waesateh ◽  
Abdulhakim Masa ◽  
Nabil Hayeemasae
Keyword(s):  
Natural Rubber ◽  
Treatment Time ◽  
Halloysite Nanotubes ◽  
Epoxidized Natural Rubber ◽  
Degree Of Crystallinity ◽  
X Ray Scattering ◽  
Natural Rubber Composites ◽  
Matrix Interactions ◽  
Strain Induced Crystallization ◽  
The Degree Of Crystallinity

Halloysite Nanotubes (HNT) are chemically similar to clay, which makes them incompatible with non-polar rubbers such as natural rubber (NR). Modification of NR into a polar rubber is of interest. In this work, Epoxidized Natural Rubber (ENR) was prepared in order to obtain a composite that could assure filler–matrix compatibility. However, the performance of this composite was still not satisfactory, so an alternative to the basic HNT filler was pursued. The surface area of HNT was further increased by etching with acid; the specific surface increased with treatment time. The FTIR spectra confirmed selective etching on the Al–OH surface of HNT with reduction in peak intensity in the regions 3750–3600 cm−1 and 825–725 cm−1, indicating decrease in Al–OH structures. The use of acid-treated HNT improved modulus, tensile strength, and tear strength of the filled composites. This was attributed to the filler–matrix interactions of acid-treated HNT with ENR. Further evidence was found from the Payne effect being reduced to 44.2% through acid treatment of the filler. As for the strain-induced crystallization (SIC) in the composites, the stress–strain curves correlated well with the degree of crystallinity observed from synchrotron wide-angle X-ray scattering.

scholarly journals Potency of Urea-Treated Halloysite Nanotubes for the Simultaneous Boosting of Mechanical Properties and Crystallization of Epoxidized Natural Rubber Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3068
Author(s):  
Indra Surya ◽  
Kamaruddin Waesateh ◽  
Sitisaiyidah Saiwari ◽  
Hanafi Ismail ◽  
Nadras Othman ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Halloysite Nanotubes ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Payne Effect ◽  
X Ray Scattering ◽  
Natural Rubber Composites ◽  
Interfacial Contact ◽  
The Matrix ◽  
Strain Induced Crystallization

Halloysite nanotubes (HNTs) are naturally occurring tubular clay made of aluminosilicate sheets rolled several times. HNT has been used to reinforce many rubbers. However, the narrow diameter of this configuration causes HNT to have poor interfacial contact with the rubber matrix. Therefore, increasing the distance between layers could improve interfacial contact with the matrix. In this work, Epoxidized Natural Rubber (ENR)/HNT was the focus. The HNT layer distance was successfully increased by a urea-mechanochemical process. Attachment of urea onto HNT was verified by FTIR, where new peaks appeared around 3505 cm−1 and 3396 cm−1, corresponding to urea’s functionalities. The intercalation of urea to the distance gallery of HNT was revealed by XRD. It was also found that the use of urea-treated HNT improved the modulus, tensile strength, and tear strength of the composites. This was clearly responsible for interactions between ENR and urea-treated HNT. It was further verified by observing the Payne effect. The value of the Payne effect was found to be reduced at 62.38% after using urea for treatment. As for the strain-induced crystallization (SIC) of the composites, the stress–strain curves correlated well with the results from synchrotron wide-angle X-ray scattering.

Cogon Grass Fiber-Epoxidized Natural Rubber Composites

2013 ◽  
Vol 747 ◽  
pp. 375-378 ◽  
Author(s):  
Chaiwat Ruksakulpiwat ◽  
Wasaphon Wanasut ◽  
Apikiat Singkum ◽  
Ruksakulpiwat Yupaporn
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Acid Treatment ◽  
Treatment Time ◽  
Treatment Method ◽  
Epoxidized Natural Rubber ◽  
Rubber Composites ◽  
Elongation At Break ◽  
Natural Rubber Composites

This research shows a great potential of cogon grass fiber to be used as a reinforcement in epoxidized natural rubber composites. The thermal and mechanical properties of cogon grass fiber-epoxidized natural rubber composites were studied. The chemical treatment of cogon grass fiber to be used as a reinforcing filler was revealed. Effects of fiber treatment method and treatment time of cogon grass fiber on thermal properties of the fibers and their composites were elucidated. The addition of cogon grass fiber into epoxidized natural rubber (ENR) improved the mechanical properties of the composites.The result indicated that alkaline treatment followed by acid treatment of cogon grass fiber led to an increase in thermal decomposition temperature and mechanical properties of the composites more than that without acid treatment. With increasing the amount of fiber, tensile strength of ENR composites were significantly increased while elongation at break was insignificantly changed. ENR with the addition of 4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate as coupling agent (ENRC) was shown to have higher tensile strength, modulus at 200% elongation and elongation at break than ENR. Improved mechanical properties were also obtained in ENRC composites compared to those of ENR composites.

Modified palm stearin compatibilized natural rubber/halloysite nanotubes composites: Reinforcement versus strain-induced crystallization

2020 ◽  
pp. 009524432092857
Author(s):  
Nureeyah Jehsoh ◽  
Indra Surya ◽  
Kannika Sahakaro ◽  
Hanafi Ismail ◽  
Nabil Hayeemasae
Keyword(s):  
Natural Rubber ◽  
Palm Stearin ◽  
Halloysite Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Strain Induced Crystallization ◽  
Diffraction Patterns ◽  
The Relationship ◽  
Induced Crystallization

Natural rubber (NR) is known as hydrophobic material and is incompatible with hydrophilic filler such as halloysite nanotubes (HNTs). To overcome this obstacle, the compatibilizer is a material of choice to incorporate in such compound. In this study, bio-based compatibilizer was used which was prepared by modification of palm stearin. The presence of special functionalities of modified palm stearin (MPS) was confirmed by Fourier transform infrared (FTIR) analysis. It was then varied from 0.5 phr to 2 phr to the NR matrix. Here, the properties were evaluated through the mechanical properties with special attention to the relationship between their reinforcement and crystallization behavior after stretching. It was found that the addition of MPS significantly enhanced the modulus, tensile strength, and tear strength of the composites. This clearly corresponded to interaction between NR and HNT promoted by MPS. The FTIR spectrum, X-ray diffraction patterns, and scanning electron microscopy images were also utilized to verify the behavior of MPS in the NR/HNT composites. As for the crystallization of the composites, the results obtained from stress–strain curves are in very good agreement to the outputs observed by the synchrotron wide-angle X-ray scattering. This corresponding interaction of MPS has greatly influenced on assisting the strain-induced crystallization of composites.

scholarly journals Impact of environmental agents on non-woven polylactide/natural rubber agrofiber

2021 ◽  
Vol 285 ◽  
pp. 07034
Author(s):  
Yulia Tertyshnaya ◽  
Maksim Zakharov ◽  
Alina Ivanitskikh ◽  
Anatoliy Popov
Keyword(s):  
Natural Rubber ◽  
Uv Irradiation ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
Distilled Water ◽  
Fibrous Materials ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Environmental Agents ◽  
The Degree Of Crystallinity

In the work an eco-friendly non-woven fiber made of polylactide and natural rubber with a rubber content from 0 to 15 wt.% was obtained by electrospinning. The influence of distilled water and UV irradiation on the agrofibers has been investigated. The water sorption test showed that the addition of natural rubber into the polylactide matrix does not significantly affect the degree of water absorption of the fibrous materials, which is in the range of 49-50.6%. Thermal characteristics after 180 days of degradation in distilled water at 22±2 oC and UV irradiation at a wavelength of 365 nm during 100 hours were determined using the differential scanning calorimetry. Changes in the values for glass transition and melting temperatures, and the degree of crystallinity were determined.

The Effect of Epoxidation on Strain‐Induced Crystallization of Epoxidized Natural Rubber

2019 ◽  
Vol 40 (14) ◽  
pp. 1900042 ◽  
Author(s):  
Xi Zhang ◽  
Kaijing Niu ◽  
Weixiao Song ◽  
Shouke Yan ◽  
Xiuying Zhao ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Graphene networks and their influence on free-volume properties of graphene–epoxidized natural rubber composites with a segregated structure: rheological and positron annihilation studies

2015 ◽  
Vol 17 (18) ◽  
pp. 12175-12184 ◽  
Author(s):  
Canzhong He ◽  
Xiaodong She ◽  
Zheng Peng ◽  
Jieping Zhong ◽  
Shuangquan Liao ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Positron Annihilation ◽  
Free Volume ◽  
Epoxidized Natural Rubber ◽  
Interfacial Region ◽  
Rubber Composites ◽  
Natural Rubber Composites ◽  
Volume Properties ◽  
Geometric Confinement ◽  
Segregated Structure

The motion of ENR chains is retarded by the geometric confinement of “GE networks”, producing a high-density interfacial region in the vicinity of GE nanoplatelets.

The Degree of Crystallinity in Natural Rubber. IV. The Degree of Crystallization in Frozen Raw Rubber and Stretched Vulcanized Rubber

1950 ◽  
Vol 23 (2) ◽  
pp. 310-319 ◽  
Author(s):  
J. M. Goppel ◽  
J. J. Arlman
Keyword(s):  
Natural Rubber ◽  
Experimental Evidence ◽  
Theoretical Investigation ◽  
Degree Of Crystallinity ◽  
X Ray ◽  
Crystallization Point ◽  
Vulcanized Rubber ◽  
Degree Of Crystallization ◽  
The Degree Of Crystallinity

Abstract An improved x-ray technique has been worked out to determine the degree of crystallinity in natural rubber. Inaccuracies which sometimes occur in quantitative x-ray measurements were eliminated, and it has been shown that the amount of crystalline rubber, both in frozen samples of raw rubber and in stretched vulcanized rubber, could be determined fairly accurately. More experiments were carried out and the results are described. These results, which confirm the current views on the problem of crystallization, point to relatively low degress of crystallization, even in highly stretched rubber, and they agree with some other experimental evidence and with a recent theoretical investigation.

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