Effect of Physical and Chemical Surface Treatment on the Thermal Stability of Hemp Fibers as Reinforcement in Composite Structures

2011 ◽  
Vol 71-78 ◽  
pp. 616-620 ◽  
Author(s):  
Na Lu ◽  
Shubhashini Oza

Hemp fiber is an excellent sustainable and renewable alternative to glass fiber as a reinforcing component in composite system, owing to its unique features of fast growth, high mechanical strength, low density, low cost, biodegradable, and low energy consumption. In this study a systematic investigation of physical and chemical treatment on hemp fiber was conducted, and their effects on thermal stability of hemp fiber were analyzed. Oxygen plasma treatment was used as physical modification approach, 5 wt% sodium hydroxide solution was used for chemical modification. Surface chemical composition and thermal stability were characterized by Fourier transform infrared spectroscopy and thermo gravimetric analysis. The results indicated that 5 wt% of NaOH with 16 hours treatment time increased hemp fiber thermal stability, while the plasma treatment had no impact on thermal stability of hemp fiber.

2011 ◽  
Vol 415-417 ◽  
pp. 666-670 ◽  
Author(s):  
Na Lu ◽  
Shubhashini Oza ◽  
Ian Ferguson

Natural fiber reinforced composites are being used as reinforcement material in composite system due to their positive environmental benefits. Added to that, natural fibers offer advantages such as low density, low cost, good toughness, high specific strength, relatively non-abrasive and wide availability. However, the low thermal stability of natural fibers is one of the major challenges to increase their use as reinforcing component. In this study, a thorough investigation has been done to compare the effect of two chemical treatment methods on the thermal stability of hemp fibers. 5wt% sodium hydroxide and 5wt% triethoxyvinylsilane was used for the treatment of hemp fibers. Fourier transform infrared spectroscopy, scanning electron microscopy and thermo gravimetric analysis were used for characterization of untreated and treated fiber. The results indicated that 24 hours alkali treatment and 3 hours silane treatment time enhanced the thermal stability of the hemp fiber. However, alkali treatment shows better improvement compared to silane treatment.


2016 ◽  
Vol 857 ◽  
pp. 191-195 ◽  
Author(s):  
A. Nadiatul Husna ◽  
Bee Ying Lim ◽  
H. Salmah ◽  
Chun Hong Voon

Palm kernel shells (PKS) filled recycled high density polyethylene (rHDPE) biocomposites were produced using melt mixing. The biocomposites were prepared on Brabender Plasticorder at temperature of 185 °C and rotor speed of 50 rpm by varying filler loading (0 to 40 phr). In this study, the effect of PKS loading on rheological properties and thermal stability of rHDPE/PKS were investigated. Rheological study of the biocomposites was carried out by means of capillary rheometer under temperature of 190 °C, 200 °C and 210 °C. Thermal properties of biocomposites were studied by using thermo gravimetric analysis (TGA). The rheological results showed that the flowability of the composite increased with increasing temperature. Meanwhile, the result of TGA showed that at higher PKS loading, rHDPE/PKS biocomposites had lower total weight loss. The thermal stability of the biocomposites was reduced due to the addition of filler loading.


2011 ◽  
Vol 374-377 ◽  
pp. 1426-1429
Author(s):  
Xiao Meng Guo ◽  
Jian Qiang Li ◽  
Xian Sen Zeng ◽  
De Dao Hong

In this study, the thermal properties of a kind of new geotextile materials, so called controlled permeable formwork (CPF), were studied. Thermo-gravimetric analysis showed that the weight of CPF didn’t change much between 0~350 °C. Dynamic mechanical analysis showed that the storage modulus of CPF reduced from 25 MPa to around 10 MPa when the temperature rose to above 100 °C. The strength of sample decreased slightly with the increase of the temperature. The breaking elongation changed slightly with a maximum at 80 °C. The CPF showed excellent thermal stability and was suitable for general use in construction work.


2011 ◽  
Vol 45 (25) ◽  
pp. 2595-2601 ◽  
Author(s):  
Tsuyoshi Saotome ◽  
Ken Kokubo ◽  
Shogo Shirakawa ◽  
Takumi Oshima ◽  
H. Thomas Hahn

Novel nanocomposite films of polycarbonate (PC) with fullerene derivatives, such as pristine fullerene C60 and polyhydroxylated-fullerenes, C60(OH)12 and C60(OH)36, were prepared. The optical, thermal, and mechanical properties of the composites were measured. Nanocomposite films of poly (vinyl alcohol) (PVA) with C60(OH)36 were prepared as a reference to show how improved dispersion of the nanofiller affects the overall transparency of the composites. Ultraviolet-visible spectroscopy showed that the addition of hydroxylated fullerenes did not affect visible light transmittance of the films significantly in the range of 400–800 nm. Differential scanning calorimetry (DSC) and thermo–gravimetric analysis (TGA) measurements showed the increased thermal stability of PC/C60(OH)12 film as compared to pristine PC film. This phenomenon was explained by the rigid polymer interphase regions formed around C60(OH)12 due to the plausible hydrogen bonding and hydrophobic interaction. On the other hand, the lower thermal stability of PC–C60(OH)36 was assumed to be caused by large agglomeration of the C60(OH)36 particles and the partial hydrolysis of the polycarbonate matrix. Tensile testing of the composites showed reduction in elongation at break and yield tensile strength. These results may be caused by the particle agglomerations which act as the initiation points for cracks.


2014 ◽  
Vol 6 (2) ◽  
pp. 1122-1134 ◽  
Author(s):  
Mokhtar Hemdan Abd El-Salam

Due to the light weight, high specific strength and non hazardous nature of bamboo fiber, it is preferred over synthetic fibers in composite materials for a wide range of applications such as automotive industry and including household sectors. As was noticed, little attention has been given to the effect of bamboo powder on the mechanical properties of rubber composites. Hence, an attempt has been made in this paper to the study the effect of loading and particle size of bamboo powder on the mechanical properties of EPDM composites. Thermo-gravimetric analysis (TGA) was carried out to study the thermal stability of composites. Results indicated that the thermal stability of EPDM was further improved with increasing in bamboo loading and decreasing in particle size. The stress- strain curves of the composites were studied and fitted according toOgden’s model. Mechanical parameters for the studied composites were improved with increasing bamboo loading. Besides, properties such as rupture stress, and internal friction were found to be maximum for composites containing certain content of bamboo powder, depending upon its particle size. Moreover, composites containing the smallest particle size of powder, at all levels of bamboo loading, showed mechanical properties superior to all other composites. From the dynamic mechanical measurements, the dynamic modulus, internal friction, and thermal diffusivity were calculated. The observed variations were explained in view of the role played by both the loading level and the particle size of bamboo powder. These findings were supported by scanning electron microscopy (SEM) micrographs.


2014 ◽  
Vol 591 ◽  
pp. 132-136
Author(s):  
S. Manoharan ◽  
G. Ramadoss ◽  
B. Suresha

In this work, enhancement of viscoelastic behaviour and thermal stability of hybrid friction composites has been synergistically investigated. Five different friction composites were fabricated by varying weight % of basalt fiber against BaSO4 content. Dynamic mechanical analysis (DMA) was carried out to assess the temperature dependent viscoelastic behaviour of composites. Basalt fibre addition improves dynamic modulus such as storage modulus (E'), loss modulus (E") and lowers the damping factor (tan δ) values. Thermal degradation behaviour and presence of volatile elements in the composites was studied using thermo gravimetric analysis (TGA). Higher amount of BaSO4 resulted in higher thermal stability and lower % of weight loss. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis were employed to characterize the composites.


1994 ◽  
Vol 346 ◽  
Author(s):  
S. J. Kramer ◽  
J. D. Mackenzie

ABSTRACTThermal stability of a novel rubbery ORMOSIL of condensed tetraethoxysilane (TEOS) and polydimethylsiloxane (PDMS) was investigated along with methods by which to improve this stability. Based upon literature review of siloxane systems, modifications of the base ORMOSIL system was made which included substitution of polydimethyldiphenylsiloxane (PDMDPS) for PDMS, adding antioxidant, and adding iron compounds. Relative enhancement was investigated in terms of resilience measurements, and was also analyzed with thermo-gravimetric analysis (TGA) and differential thermal anaysis (DTA).


2010 ◽  
Vol 139-141 ◽  
pp. 129-132
Author(s):  
Dong Fang Li ◽  
Li Li ◽  
Jian Zhang Li

Wood plastic composite (WPC) is very useful new material in the modern society. Improving the interfacial bond strength between wood and plastic is the foundation of improving the properties of WPC. Ethylene vinyl acetate (EVA) was used as the coupling agent of WPC in this study. Thermo-gravimetric analysis (TGA) was employed to study the thermal stability of wood flour modified by EVA. The modulus of rupture (MOR), the modulus of elasticity (MOE), and the tensile strength of WPC were investigated to understand the effects of the vinyl acetate (VA) content and the melt index of EVA on WPC. The results show that EVA could improve the thermal stability of wood flour and the mechanical properties of WPC. The mechanical properties of WPC are increasing with VA content raise and melt index reducing.


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