Enhancing the mechanical and water resistance performances of bamboo particle reinforced polypropylene composite through cell separation

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dan Ren ◽  
Xuexia Zhang ◽  
Zixuan Yu ◽  
Hankun Wang ◽  
Yan Yu

AbstractIt is frequently observed that bamboo particle composites (BPCs) do not show higher mechanical performances than the corresponding wood particles composites (WPCs), although bulk bamboo is much stronger than wood in mechanical performances. Herein this phenomenon was demonstrated from the cell compositions in the applied bamboo particles. To address that, a simple method to physically separate bamboo fibers (BFs) and bamboo parenchyma cells (BPs) from a bamboo particle mixture was developed. Polypropylene (PP) composites with pure BFs, BPs, a mixture of BFs and BPs (BFs + BPs), wood particles (WPs) as fillers were prepared. The flexural and dynamic mechanical properties, water absorption, and thermal properties were determined. The BF/PP composites showed the best mechanical performances (MOR at 35 MPa, MOE at 2.4 GPa), followed by WP/PP, (BF + BP)/PP, and BP/PP. They also exhibited the lowest water absorption and thickness swelling. Little difference was found for the thermal decomposition properties. However, a lower activation energy of BF/PP compared with BP/PP implied an uneven dispersion of BFs and weaker interfacial interaction between BF and PP. The results suggest that the mechanical performances and water resistance of bamboo particle/polymer composites can be significantly improved through cell separation. However, interface modification should be applied if higher performances of BF/PP composites are required.

2013 ◽  
Vol 853 ◽  
pp. 40-45 ◽  
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen ◽  
Cheng Ho Chen

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the water absorption rate, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The water absorption of the nanocomposite specimens is then compared with that of pure glass fiber/epoxy composite specimens when tested in water. The results show that the addition of 2 wt.% SiO2 reduces the water absorption from 0.0704% to 0.0573%. The storage modulus with adding 2wt.% silica nanocomposite compared to the neat composite raises up 13.82%. Following the water absorption test, the mechanical properties of the samples are not obvious change. Therefore, the experimental results indicate that 2wt.% SiO2 addition is beneficial to the water resistance and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1128
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.


2020 ◽  
Vol 14 (1) ◽  
pp. 247-261
Author(s):  
Zineb Kerrida ◽  
Hichem Berkak ◽  
Zoubir Makhloufi ◽  
Madani Bederina ◽  
Ahmida Ferhat

Introduction: In the Polymer Concrete (PC) composites, aggregates are the most important constituent, which considerably affect their performance. The purpose of this experimental study is to examine the effect of Gravel-to-Sand (G/S) ratio on the physico-mechanical, thermal and microstructural properties of epoxy micro-polymer concrete made up of local aggregates. Materials & Methods: The Micro Epoxy Polymer Concrete (MEPC) studied consists of epoxy resin as a binder and a mixture of two types of sands (alluvial (0/0.63 mm) and dune (0/4 mm) sands), as well as crushed limestone gravel (3/8 mm). Six compositions were prepared with two epoxy resin contents (10% and 14% of the total weight of mixture) and three G/S ratios (0.25, 0.50 and 0.75). The studied properties are density, water absorption, compressive and flexural strengths, thermal conductivity, thermal diffusivity, specific heat and macrostructure. Results & Discussion: The obtained results show that the G/S ratio, as well as the epoxy resin content, has a significant influence on the properties of MEPC. In addition, 14% epoxy resin and the G/S ratio of 0.75 can be considered as optimal values, which lead to very interesting physico-mechanical performances (denser and less porous material, more resistant with almost similar thermal conductivity). Moreover, the density, the water absorption and the optical microscopic observation confirm that mixes containing 14% epoxy are more impermeable, compact and homogeneous than those containing 10% epoxy. Conclusion: Finally, it should be noted that the incorporation of aggregates being relatively coarse decreases the grains’ specific surface and reduces the porosity of the granular mix, which enable the epoxy product to completely cover the surface of mineral grains. A perfect covering of aggregate grains with a bender improves the adhesion between the aggregates and the polymer matrix.


2021 ◽  
pp. 50-58
Author(s):  
V.A. Kuznetsova ◽  
◽  
V.G. Zheleznyak ◽  
S.L. Lonskii ◽  
N.A. Kovrizhkina ◽  
...  

Adhesion, physicomechanical properties, and also kinetics of water absorption of priming coatings on basis the E-41 epoxy resin modified by liquid Thiokol 1 and by Laproxide AF, and also their phase structure are investigated. As hardeners of primer compositions organic silicon ammine ASOT-2 and low-molecular polyamide PO-200 has been used. It is shown that use of the reactive modifier Laproxide AF and hardener ASOT-2 in the epoxy and thiokol film-formers allows to receive priming coating with uniform finely divided phase structure with low porosity and high water resistance.


2021 ◽  
Vol 889 ◽  
pp. 79-84
Author(s):  
Supattra Klayya ◽  
Thawan Chotimarnon ◽  
Nattaya Tawichai ◽  
Uraiwan Intatha ◽  
Nattakan Soykeabkaew

A molded pulp is increasingly used as eco-packaging, but it has poor water resistance. Therefore, surface coating is common to perform on pulp or paper packaging to overcome this shortcoming. In this study, the bagasse (BG) molded pulp sheets were mono-and bilayer coated with nanofibrillated cellulose (NFC), modified NFC (mNFC), and shellac (S) by using a spin coating technique. Surface morphology, surface wettability, water absorption, and mechanical properties of the coated sheet samples were evaluated and compared to the uncoated sample. It was found that mNFC could effectively provide an even and complete coverage coating layer on the BG-based sheet (BG/mNFC), thanks to the partially substituted ester groups. On the contrary, NFC could not be coated evenly on the BG-based sheet surface (BG/NFC) due to its tendency towards agglomeration. The homogeneity of surface obtained from the first layer coating by NFC or mNFC affected the surface quality of the second layer coating by shellac. As a result, the BG/mNFC/S bilayer coated sample showed the smoothest surface and also the highest water resistance confirmed by SEM, contact angle measurement, and water absorption results. Furthermore, the tensile properties of both bilayer coated samples (BG/NFC/S and BG/mNFC/S) were significantly improved (p<0.05) as compared to the uncoated BG sample. This results suggested that the current bilayer coating system is very promising for advancing the performance of molded pulps in novel packaging uses.


2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940019 ◽  
Author(s):  
Chang-Mou Wu ◽  
Ri-Ichi Murakami ◽  
Syuan-Guang Lai ◽  
Po-Chun Lin ◽  
Pankaj Koinkar ◽  
...  

In this study, surface modifications and manufacturing processes for polyethylene terephthalate (PET)/polypropylene (PP) composites were developed. When non-polar PP resin is combined with polar polyester fiber, its compatibility and wettability are the key technologies. Maleic anhydride-grafted PP (MAPP) was blended with PP to improve the polarity of the PP resin and react with PET fibers. In addition, a primer was applied to the PET fabric to improve the bonding and reactivity of PET fiber and MAPP. PET/PP composites that imitated the texture and appearance of carbon fabric were prepared by thin film stacking method. The effect of MAPP and primer on interfacial bonding was evaluated by single-fiber pullout test. The mechanical properties of the PET/PP composites such as impact, and open-hole tensile strength (OHT), were studied.


2020 ◽  
Vol 15 ◽  
pp. 155892502095819
Author(s):  
Qianting Wang ◽  
Yu Zhang ◽  
Weikang Liang ◽  
Jianjie Wang ◽  
Youxin Chen

In this work, the surface of the bamboo fibers (BF) was treated with three kinds of silane coupling agents terminated with amino functional groups (KH550), epoxy functional groups (KH560), and methyl functional groups (KH570) to improve fiber–matrix adhesion. The effects of silane treatment on the mechanical properties and thermal behavior of BF/polypropylene (PP) composites were investigated. Mechanical test results showed that the order of modification effectiveness was KH570 > KH550 > KH560. KH570 treated fiber composite exhibited the best mechanical properties. The tensile strength and flexural strength of 5 wt% KH570 treatment reached to 36.1 and 54.7 MPa, which were 15.4% and 23.6% higher than those of UBF/PP composites. Simultaneously, the thermal stability increased from 467.0°C (UBF) to 470.6°C (KH-570 treated BF). An increase in crystallization temperature (1.7°C) and a decrease in crystallinity (5.8%) occurred upon the addition of 5% KH570 silanes treated bamboo fibers.


Sign in / Sign up

Export Citation Format

Share Document