scholarly journals Enhanced mechanical properties, water resistance, thermal stability, and biodegradation of the starch-sisal fibre composites with various fillers

2021 ◽  
Vol 198 ◽  
pp. 109373
Author(s):  
Maocheng Ji ◽  
Fangyi Li ◽  
Jianyong Li ◽  
Jianfeng Li ◽  
Chuanwei Zhang ◽  
...  
Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3236
Author(s):  
Peng Yin ◽  
Wen Zhou ◽  
Xin Zhang ◽  
Bin Guo ◽  
Panxin Li

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7°.


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Qun Wang ◽  
Lu Qi

AbstractA group of films mainly composed of sericin and poly(vinyl alcohol) (PVA), using boric acid (BA) as a modifier, were prepared by a technique of solution casting. In this work, the effect of BA and sericin on the mechanical properties and water resistance of the films was analyzed, the interior morphology of the films were described by a scanning electron microscopy (SEM), the thermal stability of the films was characterized by differential scanning calorimetry (DSC), and the reaction mechanism was proposed according to the previous literature and the test of Fourier transform infrared spectrum (FTIR). Results indicated that, the properties of the membrane were the functions of the blend ratio of sercin to PVA and the content of BA. The use of BA increased the tensile strength, improved the water resistance and the thermal stability, and varied the interior morphology of the films. The content of sericin greatly influenced the combination of properties of the films, especially the mechanical properties, interior morphology, thermal stability, and water resistance reducing with the increasing of sericin content. The films have potential to be used in materials, such as skin-care coatings for beauty, percutaneous drug delivery systems for exterior intact skin, due to the characteristics of the components and the good mechanical properties of the films.


2014 ◽  
Vol 941-944 ◽  
pp. 294-300 ◽  
Author(s):  
Xue Mei Pan ◽  
Min Wu ◽  
Si Dong Li ◽  
Lin Fang ◽  
Zhi Feng Wang ◽  
...  

The porous starch was modified by xanthates, and the starch/natural rubber composite was prepared by blending the modified starch with natural rubber latex. The morphology, thermal stability, swelling behavior and mechanical properties of the composite were investigated. Morphology studies by SEM showed that the modified porous starch were homogeneously dispersed in NR matrix. The composite has higher solvent resistance and lower water resistance after adding modified porous starch. The mechanical properties of composite are improved significanly with the increase of modified porous starch.


2020 ◽  
Vol 12 (11) ◽  
pp. 4411
Author(s):  
Yao-Tang Hsu ◽  
Wen-Hsin Wang ◽  
Wei-Hsi Hung

According to Taiwan’s Ministry of the Interior, from 2017 to 2019, more than 12% of house-purchase disputes were due to water leakage caused by frequent tropical rains, which have long troubled engineers. The thermal stability resistance, water resistance, and ultraviolet resistance of existing polyurethane formulations have been limited by environmental aging. Thus, the lifespan of commercial PU-coated resins (typical PU) for the waterproofing of roof surfaces is merely two to three years. Accordingly, this study proposed the introduction of siloxane and imide groups to produce waterborne poly(urethane-siloxane-imide) (Si-imide-WPU) copolymers to improve the resistance of environmental aging in typical PU. The waterproof coating resin made of Si-imide-WPU copolymers was environmentally friendly, safe to use, and free of organic solvents. The results showed that the optimal Si-imide-WPU-2 sample in the study made improvements on the defects of polyurethane (PU) including its thermal properties, mechanical properties, environmental resistance, and lifespan which could be extended up to 5.4 years. Consequently, the studied Si-imide-WPU copolymers could reduce material waste while enhancing the sustainability and efficiency of the architecture.


Author(s):  
Mohammad ZR Khan ◽  
Sunil Kumar Srivastava ◽  
MK Gupta

The present work aims to enhance the mechanical properties, thermal stability, and water resistance behavior of hybrid Pinus/Shorea robusta wood particles reinforced epoxy composites employing the chemical pre-treatments. The hybrid wood composites were prepared by hand lay-up method keeping a constant of 25 wt% of wood particles concentration with equal proportions of Pinus and Shorea robusta wood particles. The performance of the hybrid wood composite was improved by improving the interfacial bonding between wood particles and epoxy resin by chemical pre-treatments of the wood particles using silane (APTES) with varying concentrations of 2, 4, and 6 wt% and alkali (NaOH) with varying concentrations of 5%, 10%, and 15%. The mechanical properties (namely, tensile, flexural, impact, and microhardness) and water absorption properties (namely, maximum water uptake and sorption, diffusion, and permeability coefficients) of the prepared hybrid wood composites were measured. The investigations include the study of thermal degradation and crystalline behavior using thermogravimetric analysis and X-ray diffraction analysis, respectively. It was observed that the mechanical properties, thermal stability, and water resistance and crystalline behavior of the hybrid wood composites were significantly enhanced after these pre-treatments. Further, it was concluded that silane pre-treated hybrid composite with 6 wt% concentration provided the best performance than untreated as well as alkali pre-treated wood composites.


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