Effects of PMDI Modified on Physico-Mechanical Properties of Silvergrass Reinforced High Density Polyethylene Composites

2013 ◽  
Vol 750-752 ◽  
pp. 38-42
Author(s):  
Wang Wang Yu ◽  
Juan Li ◽  
Yun Ping Cao

In this study, the silvergrass (SV) was used to reinforce HDPE composites. The effects of polymeric methylene diphenyl diisocyanate (PMDI) content, slivergrass fibers content on the mechanical, water absortion of wood plastic composites (WPCs) were investigated. It was found that the mechanical properties of the SV reinforced HDPE composites can be improved by PMDI treatment. The highest tensile strength and flexural strength of the composites can be reached with 50% SV contents at the SV: PMDI=6:1. It has been proved that the hydroxyl groups of SV fibers which can react with the-NCO by FTIR. It also can be concluded that the water absorption of PMDI treated WPCs was lower than untreated ones.

2010 ◽  
Vol 150-151 ◽  
pp. 379-385
Author(s):  
Qun Lü ◽  
Qing Feng Zhang ◽  
Hai Ke Feng ◽  
Guo Qiao Lai

The wood-plastic composites (WPC) were prepared via compress molding by using the blends of high density polyethylene (HDPE) and modified polyethylene (MAPE) as the matrix and wood flour (WF) as filler. The effect of MAPE content in the matrix on the mechanical properties of the matrix and WPC was investigated. It was shown that the change of MAPE content in the matrix had no influence on the tensile strength of the matrix, but markedly reduced the impact strength of the matrix. Additionally, it had significant influence on the strength of WPC. When the content of wood flour and the content of the matrix remained fixed, with increasing the content of MAPE in the matrix, the tensile strength and the flexural strength of WPC tended to increase rapidly initially and then become steady. Moreover, with the increasing of MAPE concentration, the impact strength of WPC decreased when the low content of wood flour (30%) was filled, but increased at high wood flour loading (70%).


2018 ◽  
Vol 773 ◽  
pp. 94-99 ◽  
Author(s):  
Venitalitya Augustia ◽  
Achmad Chafidz ◽  
Lucky Setyaningsih ◽  
Muhammad Rizal ◽  
Mujtahid Kaavessina ◽  
...  

The trend of using natural fibers as green filler in the fabrication of polymer composites is increasing. One of these natural fibers is date palm fiber (DPF). Date palm fiber is considered as agricultural waste in certain areas, such as Middle East countries. Therefore, the utilization of this fiber in the composites fabrication is an interesting topic of research. In the current study, composites were prepared by melt blending DPF with high density polyethylene (HDPE). Five different DPF loadings were studied (i.e. 0, 5, 10, 20, 30 wt%). The effect of the DPF loadings on the mechanical properties and water absorption behavior of the composites were investigated. The tensile test result showed that tensile strengths of all the composites samples were all higher than the neat HDPE with the maximum improvement was achieved at the DPF loading of 5 wt% (i.e. DFC-5), which was about 19.23 MPa (138% higher than the neat HDPE). Whereas, the flexural test result showed that the flexural strength of the composites slightly increased compared to that of the neat HDPE only until 5 wt% DPF loading (i.e. DFC-5). Afterward, the flexural strength of the DFC-10 was equal to that of the neat HDPE, and decreasing with further increase of DPF loadings. Additionally, the water absorption test result showed that the water absorption rate and uptake of water (at equilibrium) increased with the increase of DPF loading.


BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 789-804
Author(s):  
Qiang Jin ◽  
Lin Zhu ◽  
Jiedeerbieke Madiniyeti ◽  
Chunxia He ◽  
Li Li

Hydration-active steel slag and slag micropowder were used as inorganic fillers with silane coupling agent (KH550) to prepare wheat straw/polyvinyl chloride wood-plastic composites (WPCs) by extrusion molding. A 35-day immersion and a pre-immersion test were carried out to analyze the influence of steel slag and slag micropowder on the physical and mechanical properties of the WPCs under wet conditions. Results showed the following: (1) KH-550 exhibited a good surface modification effect on the activated steel slag and slag micropowder, (2) an increase in the activated steel slag and slag micropowder content could effectively reduce the percent water absorption of the WPCs by 20% to 25% and the expansion by 20% to 24%, respectively, compared with the control group, but had a limited effect on the tensile strength retention, and (3) pre-immersion could effectively induce the synergistic reinforcement effect of the active fillers, resulting in reaching the saturated water absorption within 20 days. The water absorption and tensile strength were respectively 18% to 25% lower and 1.5% to 3% higher than those of the composites without pre-immersion. The results of this study could provide experimental data and theoretical references for the influence of hydration-active inorganic fillers on WPC properties.


2021 ◽  
Vol 11 (15) ◽  
pp. 6838
Author(s):  
Qinghan Yu ◽  
Yang Wang ◽  
Haoran Ye ◽  
Yequan Sheng ◽  
Yang Shi ◽  
...  

This study evaluated the mechanical and hydrophobic properties of wood plastic composites (WPC) prepared by the hot molding approach incorporating five different recycled plastics and poplar flour. The WPC showed excellent tensile strength (36.9 MPa) and flexural strength (44.7 MPa) associated with good hydrophobicity, and the excellent properties of WPC could be due to the application of hot pressing which improved the amount of hydroxyl groups and reduced the crystallinity of WPC. The WPC also revealed a strong and hydrostable structure and negligible emission of formaldehyde during the preparation process. Overall, the WPC could be used to substitute traditional wood-based panels as potential furniture material, hence achieving sustainable utilization of plastic wastes.


2014 ◽  
Vol 1004-1005 ◽  
pp. 497-500
Author(s):  
Wang Wang Yu ◽  
Dong Xue

In this study, silvergrass (SV) reinforced high density polyethylene (HDPE) composites were prepared. The effects of slivergrass fibers (SV) content on the mechanical properties, crystalline properties of wood plastic composites (WPCs) before and after water absorption were investigated. It was found that compared with the untreated WPCs after immersed into water, the tensile strength of PMDI treated composites were higher. Silvergrass can be the nucleating agent with treated by PMDI. The Xc of PMDI treated WPCs after immersed into water was also increased. However, this improved Xc has negative effect on mechanical properties.


2017 ◽  
Vol 267 ◽  
pp. 76-81 ◽  
Author(s):  
Janis Kajaks ◽  
Karlis Kalnins ◽  
Anita Zagorska ◽  
Juris Matvejs

One type of birch wood plywood by-product: plywood sanding dust (PSD) and recycled high density polyethylene (rHDPE) composites physical mechanical properties (tensile, flexural strength and modulus, impact strength and microhardness), water resistance and fluidity of the composite melts, were evaluated. These studies showed the possibility of the usage of presented by-product as an excellent reinforcement for recycled high density polyethylene matrix. It was observed that the modulus of the tensile for unmodified rHDPE+PSD composites increased up to 2.3 times, the modulus of flexural till 4 times, but the microhardness only 1.4 times. Optimal content of the PSD in recycled high density polyethylene composites could be 50 wt. %. As a coupling agent, the maleated polyethylene (MAPE) for modifying of the rHDPE+50 wt. % PSD composite was used. Due to the MAPE additives, the improvement (30-50 %) of the investigated exploitation properties was observed, but in comparison with unmodified composites the resistance of water increased up to 3.0 times. Optimal content of MAPE in rHDPE+50 wt. % PSD composition could be 3 wt.%.


2013 ◽  
Vol 423-426 ◽  
pp. 53-57
Author(s):  
Wang Wang Yu ◽  
Cai Hong Li ◽  
Juan Li ◽  
Jian Peng Zhang ◽  
Chang Wei Wang

In this study, silvergrass (SV) reinforced high density polyethylene (HDPE) composites (WPCs) were prepared by injection molding. The effects of maleated polyethylene (MAPE), slivergrass fibers content on the mechanical, Differential scanning calorimeter, morphologies of WPCs were investigated. It was found that the mechanical properties of the SV reinforced HDPE composites can be improved by MAPE treatment. The highest tensile strength and flexural strength of the composites can be reached with 40% and 50% SV contents at the fixed 8% MAPE respectively. The SV can be the nucleating agent with the addition of MAPE. SEM images of tensile fracture surfaces of treated composites demonstrated better fiber-matrix adhesion.


2020 ◽  
Vol 39 (23-24) ◽  
pp. 880-889
Author(s):  
Can Hu ◽  
Yueyun Zhou ◽  
Ting Zhang ◽  
Taijun Jiang ◽  
Guangsheng Zeng

Demand for natural fibers reinforced composites is growing as an alternative to synthetic fiber reinforced plastic composites. However, poor compatibility between natural fiber and matrix has limited its development. Therefore, it is necessary to improve their interfacial adhesion to improve the comprehensive properties of composites. In this work, sisal fibers were subjected to an alkali/polyvinyl alcohol coating treatment by an ultrasonic impregnation method, and the sisal/high-density polyethylene composite was prepared by a twin-screw extruder. The Fourier transform infrared spectroscopy was used to characterize the modification effect of sisal fiber. The surface morphology of sisal fiber and the interfacial morphology of sisal/high-density polyethylene composites were observed. The mechanical properties and water absorption of sisal/ high-density polyethylene composites were also studied. The results show that alkali/polyvinyl alcohol coating compound treatment can effectively improve the interfacial adhesion between sisal fiber and high-density polyethylene, improve the mechanical properties of composite, and reduce water absorption. Alkali/polyvinyl alcohol coating compound treatment is a very environment-friendly, cost-effective fiber modification method when compared with traditional modification methods. It is helpful for the development and application of natural fibers reinforced composites.


2017 ◽  
Vol 52 (9) ◽  
pp. 1215-1226 ◽  
Author(s):  
Ahmed Abd El-Fattah ◽  
Eman Abd ElKader

Wood plastic composites based on recycled high-density polyethylene (r-HDPE)/wood flour with the addition of organically modified clays were prepared by melt mixing and compression molding. The effect of two different types and contents of clays, bentonite and layered double hydroxide – on the mechanical, thermal, and water absorption properties of the wood plastic composites – was examined to identify the most effective clay type for wood plastic composites. It was found that incorporation of 2 wt% modified bentonite (mBNT) clay was the most effective in the composite formulation; it has significantly enhanced the properties of the wood plastic composites. The scanning electron micrographs of the fractured surfaces showed improved interfacial adhesion of the composite components. The tensile strength of wood plastic composites was increased by 9.7% when 2 wt% mBNT clay was incorporated in the composite formulation; however, the tensile strength slightly decreased as the clay content was further increased. The izod impact strength was lowered about 10.5% by 2 wt% mBNT clay. Moreover, the addition of 2 wt% mBNT clay enhanced the water resistance of the wood plastic composites by 27.5% after immersion in water for five days. On the other hand, the modified layered double hydroxide (mLDH) clay did not cause any remarkable improvement in the properties of the wood plastic composites. The tensile strength showed a decreasing trend with an increase in mLDH content. However, both clays did not improve the thermal stability of wood plastic composites. In addition, there are no noticeable changes in the values of melting temperature by increasing the content of clays. The experimental results indicated that the properties of the wood plastic composites were significantly improved when combined with the appropriate clay type and content. However, the interaction between wood flour and the intercalated clay particles as well as the processing conditions will need further study.


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