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Effects of Reinforcement Combinations of Calcium Carbonate Nanofiller on the Mechanical and Creep Properties of Polypropylene  [PDF]
Chris Chukwutoo Ihueze, Chinedum Ogonna Mgbemena
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2010, DOI: 10.4236/jmmce.2010.910065
Abstract: This paper investigated the effects of calcium cabonate nanofiller on the mechanical behavior of homo polypropylene by conducting tensile and creep tests. The Young’s Modulus of the nanocomposite showed some improvement with the incorporation of the calcium carbonate nano-filler while the tensile strength deteriorated. The stearic acid coated fillers showed the highest improvement in the above tensile properties at low volume fractions not exceeding 0.10 while the deformation rate increases with the inclusion of the nanofiller. The creep parameters evaluated include optimum elastic modulus estimated as 2GPa at 10% volume fraction, creep rate at ambient as 0.004-0.043hr-1, and creep limit at ambient as 60-113MPa as opposed to the tensile strength of PPC predicted as 45MPa for treated and 37.5MPa for untreated, all as against 123MPa for neat and unreinforced PP, though at 0.05 volume fraction the tensile strength was evaluated as 140MPa and 133.3MPa for coated and uncoated PPC respectively.
The Effect of Water Absorption on Mechanical Properties of Wood Flour/Wheat Husk Polypropylene Hybrid Composites  [PDF]
Pradeep Upadhyaya, Manoj Garg, Vijai Kumar, Ajay K. Nema
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.35047
Abstract: The main objectives of this research were to study the effect of water absorption on mechanical properties of hybrid fiber reinforcement for polypropylene composites. The poor resistance towards water absorption is one of the draw- backs of natural fibers. Hybrid filler-polypropylene composites are subjected to water immersion tests in order to study the effects of water absorption on the mechanical properties. Composites specimens containing 30 phr and 40 phr fiber weight were prepared by melt blending process. Water absorption tests were conducted by immersion specimens in distilled water at room temperature for different time durations (24, 48, 72, 96, 120, 144, 168, 192 hours). The tensile, flexural and impact properties were investigated before and after water absorption. The percentage of moisture uptake increased as the increasing order of the filler loading due to the high cellulose content. The phase morphology of wood flour/wheat husk polypropylene hybrid composites were investigated by SEM, the dynamic mechanical properties of the composite are analyzed by DMA & wheat, wood filler interaction are analyzed by FT-IR.
Properties of bamboo flour/HDPE composites modified by bauxite

- , 2015, DOI: 10.13801/j.cnki.fhclxb.20141105.005
Abstract: 为制备高性能的木塑复合材料, 扩展其应用领域, 采用A-171硅烷偶联剂对竹粉进行表面改性, 并添加一定量的铝矾土, 经热压成型制备了竹粉/高密度聚乙烯(HDPE)复合材料。分析了铝矾土用量对竹粉/HDPE复合材料力学性能、耐热性和摩擦性能的影响。采用XRD分析了铝矾土的结晶特性, 利用SEM和EDS分析了竹粉/HDPE复合材料的断面形貌和表面元素分布情况。结果表明:加入适量铝矾土后, 竹粉/HDPE复合材料的力学强度、耐热性及耐磨性能得以改善。铝矾土在竹粉/HDPE复合材料基体中分布均匀, 可有效承担载荷, 同时提高了竹粉/HDPE复合材料的结晶性能, 降低了竹粉/HDPE复合材料在外在应力下引起的变形和破坏;但铝矾土用量过高, 分布不均匀, 容易形成团聚现象, 导致竹粉/HDPE复合材料的力学强度和耐磨性降低, 线性热膨胀系数增大。 For preparing high-performance wood plastic composites and broading the application fields, the surface of bamboo flour was modified by A-171 silane coupling agent and an amount of bauxite was added into it. The bamboo flour/high density polyethylene (HDPE) composites were prepared by hot pressing technology. The influence of bauxite content on mechanical properties, heat resistance and tribological behavior of the bamboo flour/HDPE composites were investigated. The crystallization characteristics of bauxite were observed using XRD and their morphology of fracture surface and distribution of elements on the surface were analyzed by SEM and EDS. The results show that the mechanical strength, heat resistance and the wear resistance of bamboo flour/HDPE composites are improved by adding the appropriate content of bauxite. Bauxite can be evenly distributed in bamboo flour/HDPE composite matrix and bear the load effectively, and the crystallization properties of bamboo flour/HDPE composites are improved. The deformation and failure of bamboo flour/HDPE composites under exterior stress were reduced. However, when the content of bauxite is too high, the mechanical strength and the wear resistance decrease, and the coefficient of linear thermal expansion of bamboo flour/HDPE composites increases, because that the bauxite is unevenly distributed and formes agglomeration easily. 四川省教育厅重点项目(10ZA042)
Improve toughness of wood flour/HDPE composites with elastomers

- , 2016, DOI: 10.13801/j.cnki.fhclxb.20151223.003
Abstract: 为提高木塑复合材料的韧性,在木粉/高密度聚乙烯(WF/HDPE)复合材料制备过程中引入了3种弹性体:聚烯烃弹性体(POE)、弹性体改性聚乙烯(BPB)和接枝改性的聚烯烃弹性体(A669)。通过对WF/HDPE复合材料冲击强度和抗弯弹性模量的测试,确定出既能有效提高WF/HDPE复合材料韧性又能维持材料刚性的增韧剂种类及其用量,并通过结晶行为、热力学性能及界面结合分析等探讨了其增韧原理。通过对比可知, A669的增韧效果最为明显,质量分数为4%时冲击强度达到15.31 kJ/m2,相对于无添加配方提高了52.34%且抗弯弹性模量只下降6.09%。XRD和DSC分析结果表明:A669的添加阻碍了WF/HDPE复合材料的结晶行为,使其在略低的温度下才可以结晶,且结晶度下降,晶粒尺寸增大,衍射角所对应的衍射面增大,因此吸收和损耗了更多的能量;A669的添加还降低了WF/HDPE复合材料的玻璃态转变温度。DMA和SEM分析结果显示:A669的添加使WF/HDPE复合材料呈现出显著的黏性特征,断裂面的HDPE塑料基质出现拉丝现象,从而达到提高材料韧性的效果。转矩流变测试表明A669的添加使WF/HDPE复合材料的扭矩略有降低,对加工没有不利影响。适当添加A669可以使木塑复合材料同时具备良好的韧性和刚性,对扩大其在建筑模板等领域的应用具有重要意义。 Three kinds of elastomers, polyolefin elastomer (POE), elastomer modified polyethylene (BPB) and graft modified polyolefin elastomer (A669) were introduced to preparation process of wood flour/high density polyethylene (WF/HDPE) composite to improve the toughness of wood-plastic composites. The kinds and contents of toughening agent at which can simultaneously improve the toughness and maintain the rigidity of WF/HDPE composites were determined by the impact strength and flexural elastic modulus test of WF/HDPE composites. The toughening principles were analyzed by the aid of the crystallization behavior, thermal dynamic property and interface bonding analysis. Through comparison, it shows that A669 is the most effective one; when adding mass fraction is 4%, the impact strength is 15.31 kJ/m2, increases by 52.34% comparing to the composite without A669, while the flexural elastic modulus just decreases by 6.09%. XRD and DSC analysis results show that, adding A669 hinders the crystallization behavior of WF/HDPE composites, which decreases the crystallization temperature and the crystallinity, while increases the grain size and the size of the diffraction surface corresponding to the diffraction angle. Thus more energy is absorbed and lost, and the glass transition temperature of WF/HDPE composite decreases. The DMA and SEM analysis results show that, the WF/HDPE composites with A669 present more viscosity characteristic, and the wiredrawing phenomenon of plastic matrix appears on the fracture surface, improving the toughness of the material. The torque rheometer test shows that, the balance torque of WF/HDPE composites does not change significantly, which indicates that A669 will not adversely affect the processing. Therefore, A669 can provide wood-plastic composite with both good toughness and stiffness under an appropriate use level. The results of present study will greatly promote the application of wood-plastic composite in building templates etc.
Effect of wood filler treatment and EBAGMA compatibilizer on morphology and mechanical properties of low density polyethylene/olive husk flour composites
eXPRESS Polymer Letters , 2007, DOI: 10.3144/expresspolymlett.2007.65
Abstract: This paper deals with plastic-wood composites based on low density polyethylene (LDPE) and olive husk flour (OHF). The problem of incompatibility between the hydrophilic wood filler and the LDPE hydrophobic matrix was treated by two methods: a chemical modification of the olive husk flour with maleic anhydride to esterify the free hydroxyl groups of the wood components and the use of a compatibilizer agent, i.e. an ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) terpolymer. The changes in the structure, the morphology, and the properties resulting from these treatments were followed by various techniques, especially FTIR spectroscopy, scanning electron microscopy (SEM), tensile measurements and water absorption. The experimental results indicated that both methods, i.e. the chemical treatment of the olive husk flour with maleic anhydride and the inclusion of EBAGMA terpolymer, improved the interactions between the two composite components and promoted better dispersion of the filler in the matrix. Moreover, ultimate tensile properties were also increased. However, the use of EBAGMA terpolymer as compatibilizer produced better enhancement of the properties of LDPE/OHF composites compared to those treated with maleic anhydride.
The Influence of Fiber Length and Concentration on the Physical Properties of Wheat Husk Fibers Rubber Composites  [PDF]
Maged S. Sobhy,M. T. Tammam
International Journal of Polymer Science , 2010, DOI: 10.1155/2010/528173
Abstract: Ethylene-propylene-diene terpolymer (EPDM)/wheat husk fibers (WHFs) composites were prepared using a laboratory size two-roll mill. Cure characteristics and some physical properties such as swelling, mechanical, and thermal properties of the vulcanizates were studied. The adhesion status between the WHF and rubber matrix is lacked in general, but it started to reinforce the matrix at higher WHF contents where a higher restriction to molecular motion of the macromolecules with uniformed stress distribution of the fibers is produced. From the TGA analysis, a thermally stable property is exhibited, which in turn partially enhanced the reinforcement of the WHF-EPDM composites due to the natural adhesion during vulcanization. 1. Introduction Natural fibers are subdivided based on their origins, coming from plants, animals, or minerals. Natural Plant-fibers are grouped into four types: seed hairs (cotton, kapok), bast-fibers (flax, hemp, jute, ramie), leaf-fibers (sisal, henequen, coir, abaca), and wood flour (wheat husk, rice husk) [1–5]. It is well known that wheat husk fibers were employed in Egypt [1] for a very long time ago for buildings as construction materials mixed with clay. Generally, the different types of natural fibers are used to reinforce plastics (thermosets as well as thermoplastics) and reach the mechanical properties of glass-fiber composites, and they are already applied, for example, in automobile and furniture industries due to their relative high strength and stiffness and low density [5]. Composites can be tailored to have the desired properties by incorporating particulate fillers into a polymer matrix to suit different applications [6]. For economic and environmental reasons [7, 8], there is an increasing use of polymer composites filled with lignocellulosic materials such as wood flour, rice husk, wheat husk, jute, and sisal [9–12]. The main disadvantage encountered during the incorporation of natural lignocellulosic materials into polymers is the lack of good interfacial adhesion between the two components, especially in the case of rubbers, due to the incompatibility of hydrophilic natural fibers that are to be used as reinforcement with hydrophobic polymer matrix [13, 14]. Furthermore, these composites are often associated with agglomeration as a result of insufficient dispersion, caused by the tendency of fillers to also form hydrogen bonds with each other during processing [13–15]. Moreover, the polar hydroxyl groups on the surface of the lignocellulosic materials have difficulty in forming a well-bonded interface with a
Comparison of properties between rice husk/high density polyethylene and rice husk biochar/high density polyethylene composites

- , 2018, DOI: 10.13801/j.cnki.fhclxb.20180227.002
Abstract: 采用挤出法制备稻壳/高密度聚乙烯(HDPE)和稻壳炭/HDPE复合材料。利用SEM、XRD对稻壳/HDPE和稻壳炭/HDPE复合材料进行表征,并对其力学性能和抗蠕变性能进行测试对比。结果表明,稻壳和HDPE之间的结合方式与稻壳炭和HDPE之间的结合方式存在根本性的差异,稻壳/HDPE复合材料表现为稻壳被HDPE所包裹,稻壳炭/HDPE复合材料表现为HDPE嵌入稻壳炭的孔隙中;稻壳和稻壳炭的加入都会影响HDPE基复合材料的结晶峰强度,但不会对其微晶结构产生影响;无论是抗弯强度、拉伸强度还是抗蠕变强度,稻壳炭/HDPE复合材料都远远强于稻壳/HDPE复合材料。 The extrusion method was applied to prepare rice husk/high density polyethylene (HDPE) and rice husk biochar/HDPE composites. The morphological properties of the rice husk/HDPE and rice husk biochar/HDPE composites were evaluated by SEM and XRD analysis, the mechanical properties and creep resistance of composites were also observed and compared. The results show that the combination of rice husk/HDPE composites is so different from rice husk biochar/HDPE composites:rice husk/HDPE composites show that the husk is covered by HDPE, rice husk biochar/HDPE composites show HDPE is embedded in the pores of rice husk biochar; The XRD shows that both rice husk and rice husk biocar can affect the intensity of the peaks of the composites but have little effect on the crystallite structure; And whether it is bending, tensile or creep resistance, rice husk biochar/HDPE composites are much stronger than those of rice husk/HDPE composites. 2016年山东省重点研发计划(重大关键技术)(2016ZDJS11A01);山东省泰山学者特聘专家;山东省高等学校优势学科人才团队培育计划

WANG Hui-min,YI Xiao-su,

高分子学报 , 1992,
Abstract: The mechanical property and microscopic morophology of self-reinforced HDPE were investigated. The tensile strength and modulus of self-reinforced HDPE, compared with those of normal HDPE, were enhanced appreciably. The morphological structure was changed as a result of self-reinforcement. The shish-kebab and the fibrous structure in self-reinforced HDPE were given credit for its excellent property.
Kantima Chaochanchaikul,Krishnan Jayaraman,Vichai Rosarpitak,Narongrit Sombatsompop
BioResources , 2011,
Abstract: The aim of this work was to examine the influence the lignin component of wood on the photodegradation of high-density polyethylene (HDPE) in wood/HDPE (WPE) composites. The neat HDPE and wood/HDPE composites were prepared using a twin screw extruder followed by an injection moulder. The lignin content was varied from 0 to 29 %wt. of wood by the addition of delignified wood pulp into wood flour. The results suggested that the photodegradation of HDPE in WPE composites was accelerated by the presence of lignin; the chromophoric groups in the lignin enhanced UV adsorption onto the WPE composite surface. The carbonyl and vinyl indices, color, percentage crystallinity, and the melting temperature increased when the lignin contents were increased. The color fading in WPE composites resulted from photobleaching of lignin. In addition, the presence of lignin led to the development ofl cracks in WPE composites, especially at high lignin contents. For the effect of UV weathering time, the carbonyl and vinyl indices, discoloration, and percentage crystallinity increased as a function of UV weathering times, whereas the melting temperature of HDPE in both neat HDPE and WPE composites and water absorption of specimens decreased; the wood index in WPE composites increased during the initial UV weathering times and then decreased at 720 h weathering time.
Studies on the properties of rice-husk-filled-PP composites: effect of maleated PP
Rosa, Simone Maria Leal;Santos, Evelise Fonseca;Ferreira, Carlos Arthur;Nachtigall, S?nia Marlí Bohrz;
Materials Research , 2009, DOI: 10.1590/S1516-14392009000300014
Abstract: rice husk is a by-product of rice milling process that usually finds inadequate final disposal (burning, land filling). thermoplastics composites filled with rice husk flour are materials that offer an alternative for using this agricultural resource viewing the production of low dense materials with some specific properties. in this work composites of polypropylene (pp) and rice husk flour (rhf) were prepared by melt extrusion. maleic anhydride-modified pp (mapp) was added as a coupling agent. it was verified that tensile strength decreased with filler loading. the presence of mapp improved this property showing a strong dependence on the mapp/rhf ratio (mapp/rhf = 0.03 produced the best results). the density of the composites slightly increased with filler and coupling agent in comparison to pure pp. the presence of mapp diminished more than 20% water uptake in highly-loaded composites.
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