共查询到19条相似文献，搜索用时 395 毫秒
1.
通过双螺杆挤出、注塑方法制备了木粉(WF)、乙酰化木粉(AWF)与低密度聚乙烯(LDPE)、聚乳酸(PLA)的共混材料。采用吸水率测定、接触角测量、旋转流变仪、拉伸测试和扫描电镜(SEM)分别表征了共混材料的疏水、流变性能、力学性能和微观形貌结构。结果表明:由AWF制备的共混材料相比同质量比例的由WF制备的共混材料具有更好的疏水性能,吸水率发生了大幅度降低。随着材料中AWF含量的减少,共混材料的吸水率逐渐降低,接触角逐渐增大。流变测试表明AWF/LDPE共混材料在黏度和储能模量方面都低于WF/LDPE共混材料,AWF/LDPE共混材料的黏度和储能模量也随着AWF含量的减小而减小。力学性能测试显示由AWF制备得到的复合材料相比于由WF制备的复合材料的拉伸强度有所下降,断裂伸长率却有较大幅度的提升。SEM分析表明AWF与塑料基体的相容性得到了改善,两相之间共混分散结合更加紧密。 相似文献
2.
【目的】研究等温结晶处理对木纤维/聚乳酸复合材料结晶、物理和力学性能的影响,为提高聚乳酸复合材料的加工和使用性能提供依据。【方法】采用热压成型方式制备纯聚乳酸板材和杨木纤维(WF)/聚乳酸(PLA)复合材料,在冷却过程中将材料置于不同温度(90、100、110、120和130℃)下进行等温结晶处理,通过示差扫描量热仪(DSC)分析PLA及其复合材料的结晶度和熔融特性,利用偏光显微镜(POM)观察等温结晶处理条件下PLA的结晶过程,结合结晶形态分析等温结晶处理对PLA结晶性能的影响。基于扫描电镜(SEM)和凝胶色谱仪(GPC)等测试手段表征材料的微观结构和分子质量,分析其对材料物理力学性能的影响。【结果】等温结晶处理后,纯PLA板和WF/PLA复合材料的结晶度分别由4.6%和15.1%提高至24.8%和40.5%;经90、100和110℃等温结晶处理后,WF/PLA复合材料的冲击断面与未处理WF/PLA复合材料相比,明显有长纤维从PLA基体中拔出,等温结晶处理弱化了WF与PLA界面结合;等温结晶处理后,PLA分子质量有所下降;POM测试显示,晶体尺寸随着结晶温度升高而增大;与未处理材对比,等温结晶处理后纯PLA板的弯曲性能和拉伸强度均得到提高,WF/PLA复合材料的弯曲弹性模量增加,但弯曲强度和拉伸强度在多数处理条件下都有所降低。【结论】等温结晶处理后,纯PLA板和WF/PLA复合材料的结晶度均提高,且木纤维促进晶核生成,WF/PLA复合材料的结晶度增加更多;等温结晶温度低,晶体尺寸变小,等温结晶温度高,晶体尺寸变大;等温结晶处理后,纯PLA板的抗弯强度和拉伸强度得到提高,WF/PLA复合材料的力学性能变化规律不明显。等温结晶处理对纯PLA板和WF/PLA复合材料力学性能影响不同,可能与等温结晶处理后弱化WF与PLA界面结合有关。 相似文献
3.
采用锥形量热仪(CONE)、极限氧指数(LOI)、热重分析(TGA)和力学试验等研究手段,分析聚磷酸铵(APP)、磷酸脒基脲(GUP)及二者复配(GUP/APP)对木粉/高密度聚乙烯(WF/HDPE)复合材料燃烧性能、热降解行为以及力学性能的影响.CONE研究结果表明:APP可显著降低WF/HDPE复合材料的热释放,但同时也使得复合材料的烟释放增加;将GUP与APP按适当比例复配不仅可以有效抑制复合材料的热释放,而且可以降低烟释放速率,表现出较好的协同阻燃和抑烟作用.TGA结果表明:GUP与APP复配使得WF/HDPE复合材料的初始热分解温度降低,残炭产率提高.此外,GUP和APP复配阻燃WF/HDPE复合材料具有较高的氧指数和较小的力学性能损失. 相似文献
4.
GUO Chui-gen WANG Qing-wen MOE Key Laboratory of Bio-based Material Science Technology Northeast Forestry University Harbin P. R. China 《林业研究》2007,(3)
马来酸酐接枝苯乙烯-乙烯-丁烯-苯乙烯(MA-SEBS)用作聚丙烯/木纤维复合体系的界面相容剂及冲击改性剂,来提高其界面粘接及冲击强度。研究了MA-SEBS含量对PP/WF复合材料冲击断裂行为的影响,当MA-SEBS含量达到8%时,冲击性能达到了最大值,进一步增加到10%并未提高其断裂韧性,但动态热机械分析(DMA)表明复合材料刚性的提高,这归因于PP/WF界面的改善,当MA-SEBS超过8%,聚丙烯与木纤维分子间的相互作用增强。扫描电子显微镜(SEM)分析了样品的断裂表面,表明木纤维与聚丙烯表面强烈的界面粘结。图5表1参11。 相似文献
5.
以甲基丙烯酸甲酯(MMA)、丙烯酸正丁酯(BA)和α-甲基丙烯酸(α-MAA)为单体,通过种子乳液聚合制备了聚丙烯酸酯乳液共聚物(PMBM),研究了PMBM玻璃化温度(Tg)分别为80、60和40℃的S1、S2和S3及添加量对纤维素基脲醛树脂模塑料的收缩率、力学性能及热稳定性能等影响,并采用动态力学机械分析(DMA)和电镜扫描(SEM)研究了改性前后脲醛树脂模塑料动态力学性能和冲击断面的微观结构。结果表明,玻璃化温度为40℃的PMBM(S3)对脲醛树脂模塑料的增韧效果最好;当S3添加量为20%时,脲醛树脂模塑料韧性最好,其模塑料收缩率为0.23%,冲击强度为2.47 k J/m2,弯曲强度为75.16 MPa,其中冲击强度和弯曲强度分别比未改性的脲醛树脂模塑料提高了44.4%和39.0%;添加PMBM会降低脲醛树脂模塑料体系的热失重速率,模塑料耐低温性能得到提高。由DMA测试结果可知,S3对模塑料的增韧效果显著,且与脲醛树脂的相容性较好;此外,由SEM分析可知添加20%S3增韧的模塑料断面粗糙,断口光滑,趋于韧性断裂。 相似文献
6.
以淀粉和木粉为原料,甘油为增塑剂,通过挤出成型制备淀粉/木粉可生物降解复合材料,重点研究淀粉/木粉混合比例对复合材料性能的影响。采用扫描电镜（SEM）、X射线衍射仪（XRD）和热重分析（TGA）对复合材料进行表征,并对复合材料的力学性能和吸水性能进行测试。实验结果表明：木粉的加入破坏热塑性淀粉的连续性,使复合材料的结晶度增大。复合材料的拉伸强度、吸水率和吸水厚度膨胀率随着木粉比例增大逐渐增大,断裂伸长率却逐渐降低。TGA测试结果表明,随着木粉加入比例增大,复合材料的热分解起始温度逐渐降低,但热分解的终止温度逐渐升高,淀粉和木粉两相依赖性逐渐减弱。 相似文献
7.
【目的】通过木粉纤维增强生物塑料聚3-羟基丁酸酯-co-4-羟基丁酸酯(P34HB),为生物复合材料的理论研究和生物可降解塑料的广泛应用提供科学依据和理论支持。【方法】以毛白杨木粉和P34HB为原料,采用共混热压法制备P34HB/木粉生物复合材料,基于电子扫描显微镜(SEM)、差示扫描量热法(DSC)、热重分析(TGA)、傅里叶红外光谱(FTIR)、动态热机械分析(DMA)和力学性能分析等手段对其结构和性能进行表征。【结果】随着木粉含量增加,生物复合材料的拉伸强度、断裂伸长率和弯曲强度先增加后减小,冲击强度逐渐下降,拉伸强度、弹性模量和杨氏模量分别增加89%、59%和103%,储能模量E′逐渐增加,tanδ峰值先下降后上升。生物复合材料的高频率模量大于低频率模量,动刚度比静刚度好。相比P34HB,生物复合材料的热分解区间变宽,热解速率变慢,热解剩余质量增加。【结论】随着木粉含量增加,P34HB分子链运动受阻,生物复合材料的储能模量和脆性增大;同时,木粉纤维的成核作用诱导P34HB形成结晶度高、层状结构发达的横晶层,木粉与P34HB之间界面结合力增强,力学性能和热稳定性明显提高。综合考虑,P34HB/木粉生物复合材料的最佳木粉加入量为50%。 相似文献
8.
《林产化学与工业》2017,(3)
使用三聚氯氰(TCT)对原料杨木粉(RWF)进行改性,并使用改性木粉(TWF)与油胺(OAM)在聚乳酸(PLA)体系下反应后挤出制备复合材料。红外光谱表明:TCT的三嗪环结构连接到了木粉上,在反应挤出过程中,TWF接枝上了OAM。元素分析和滴定分析表明:TWF增加的氮元素与氯元素的物质的量比为2.91∶1,TCT上3个活性氯中的两个参与了反应。OAM加入导致PLA产生了降解,但复合材料PLA/TWF/OAM降解弱于PLA/RWF/OAM;在相同OAM用量下,PLA/TWF/OAM拉伸强度和弯曲强度均优于PLA/RWF/OAM;在相同木粉用量下,PLA/TWF/OAM的熔体流动速率大于PLA/RWF。动态力学性能分析表明:在相同OAM用量下,PLA/TWF/OAM与PLA/RWF/OAM相比具有较高的玻璃化转变温度。 相似文献
9.
纳米纤维素增强木塑复合材料的性能研究 总被引：1，自引：0，他引：1
《林产化学与工业》2015,(5)
以杨木粉为原料制备出纳米纤维素(CNF),然后采用物理预处理法和聚氧化乙烯(PEO)分散剂法利用CNF增强木粉/高密度聚乙烯(HDPE)复合材料,通过挤出成型的方式制备CNF/HDPE/木粉复合材料。以直接干混法制备的复合材料为对照样,比较了2种预处理方法对CNF的分散程度和对木塑复合材料的增强效果,并对样品的微观形貌和力学特性进行了分析与测定。结果表明:经酸碱处理和研磨处理可有效去除杨木中的半纤维素和木质素,并得到直径几百纳米的纤维素纤丝。SEM分析表明,2种预处理方式制备的CNF/HDPE/木粉复合材料都取得了较好的分散效果,纤维不再是以分散相填充在塑料中,而是以三维网状细丝结构穿刺于塑料和木粉颗粒中,复合材料由脆性断裂变为韧性断裂。力学性能测试结果表明,2种预处理方式制备的CNF/HDPE/木粉复合材料的抗弯强度和弹性模量都有了显著的提高,当CNF的添加量为20%时,利用物理预处理法和PEO分散剂法制备的复合材料的抗弯强度为43.3和38.7 MPa,相比于对照样(31.8 MPa),分别提高了36.2%和21.7%,弹性模量为3 342和3 008 MPa,相比于对照样(2 243 MPa),分别提高了48.9%和34.1%,均达到了预期的增强效果;且物理预处理法增强效果更好,是一种环保而有效的预处理方法。 相似文献
10.
11.
MA-SEBS as compatibilizer and impact modifier was incorporated into Polypropylene/Wood Fiber （PP/WF） to enhance interface adhesion and impact strength of the composite. The effect of MA-SEBS content on the impact fracture behavior of PP/WF composites was studied. The impact properties of composites with 8% MA-SEBS reached the maximum value. And further increasing of MA-SEBS content to 10% did not improve the fracture toughness, but improved the stiffness of composites by DMA analysis. This was attributed to the improved PP/WF adhesion. As the MA-SEBS content is more than 8%, the molecule interaction of PP and WF was expected to much stronger than lower MA-SEBS. Scanning electron microscopy （SEM） was performed to analyze the impact fracture surface and showed a stronger affinity for the wood surfaces. 相似文献
12.
Dynamic-mechanical analysis and SEM morphology of wood flour/polypropylene composites 总被引：1，自引：0，他引：1
GUO Chui-gen SONG Yong-ming WANG Qing-wen SHEN Chang-sheng 《林业研究》2006,17(4):315-318
Introduction It is well known that over the past few decades, polymers have replaced many conventional materials, such as metal and wood in many applications. This is due to the advantages of polymers over conventional materials (Maurizio et al. 1998; Adr… 相似文献
13.
Wood flour (WF) and polypropylene (PP) composites (WF/PP) were compatibilized by m-isopropenyl-α,α-dimethylbenzyl isocyanate grafted polypropylene (m-TMI-g-PP). The effect of wood flour, m-TMI-g-PP contents on the rheology, dynamic mechanical analysis (DMA), mechanical properties, as well as the morphology of the composites were investigated and discussed. Rheology, DMA results showed that m-TMI-g-PP was an effective compatibilizer for WF/PP composites. The shear modulus (G′) and complex viscosity (η*) of the composites were increased, which implied that the composites probably withstood pronounced shear forces, resulting from strong adhesion at the interface between the matrix PP and WF. The mechanical test indicated that the tensile strength and the flexural strength of the composites were improved with increasing content of m-TMI-g-PP. From the properties tests, the optimum loading of WF in WF/m-TMI-g-PP/PP was found to be 40%, and the optimum loading of m-TMI-g-PP was 6%. Property enhancement is attributed to improved wetting and interactions between the PP matrix and WF, which is supported by scanning electron microscopy analysis. 相似文献
14.
Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare FF reinforced WF/PE composites(FF/WF/PE).Mechanical testing,dynamic mechanical analysis,scanning electron microscopy(SEM),creep measurement and Torque rheology were used to characterize the resulting composites.The results indicate that the mechanical performance of the composites could be remarkably improved by adding a limited amount of FF.The flexural strength and modulus increased by 14.6 and 51.4%,respectively(FF content of 9 wt%),while the unnotched impact strength could be increased by 26.5%(FF content of12 wt%).The creep resistance and toughness of thecomposite was markedly improved without changing the plastic content of the composite material. 相似文献
15.
ABSTRACTIn this study, wood flour/polypropylene (WF/PP) composites were prepared by incorporating 2?wt% carbon materials with different morphologies, including carbon black (CB), graphite (G), and multi-walled carbon nanotubes (CNTs). WF/PP composite without any additives was included as a reference. All composites were placed in the accelerated UV weathering tester for a total of 960 h. The physical and mechanical properties of composites were compared. The changes in surface morphology and surface chemistry were characterized by SEM AFM, and ATR-FTIR. The results showed that: (1) the addition of CNTs improved both flexural and impact properties of composites; (2) composites containing CNTs exhibited better color stability and less severe surface cracking during weathering; and (3) ATR-FTIR results revealed that all the additives alleviated surface photo-oxidation of composites due to their UV-screening effect. Overall, due to the improved interfacial bonding between WF and PP, CNTs were more effective in protecting wood–plastic composites from photodegradation. 相似文献
16.
Wenjie Dang Yongming Song Qingwen Wang Weihong Wang 《Frontiers of Forestry in China》2008,3(2):243-247
To improve the interfacial compatibility between wood fibers and polypropylene and the toughness of wood-fiber/polypropylene
composites, maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted styrene-ethylene-butadiene-styrene
copolymers (SEBS-g-MAH) were used as modifiers. Mechanical properties of wood-fiber/polypropylene (WF/PP) composites were
improved when PP-g-MAH or SEBS-g-MAH was added. When either of these copolymers was added, the composites had better interfacial
compatibility than the unmodified composite. This was verified by scanning electron microscope (SEM) observations and dynamic
mechanical analysis (DMA). The mechanical properties of the composites were significantly improved because of the good interfacial
bonding between wood fibers and polypropylene when PP-g-MAH and SEBS-g-MAH were added.
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Translated from Journal of Beijing Forestry University, 2007, 29(2): 133–137 [译自: 北京林业大学学报] 相似文献
17.
In this paper, the influence of melamine polyphosphate (MPP) and aluminum hypophosphite (AHP) on mechanical properties, flame retardancy and thermal degradation of high-density polyethylene/wood flour composites (HDPE/WF) was investigated. The synergistic effect of MPP and AHP was investigated. Polyethylene grafted with maleic anhydride (PE-g-MAH) was used as coupling agent. The experimental data demonstrated that the HDPE/WF composites with 35 wt% MPP/AHP (3:2) could achieve a LOI value of 29.6 % and UL-94 V-0 rating. In addition, the cone value also revealed that the heat release rate and the smoke production rate were clearly reduced. SEM results showed that the synergistic system (MPP/AHP = 3:2) could form a dense and thick char layer and good adhesion between wood flour and HDPE matrix, which prevented the transfer of heat flux and fuel gases. Incorporation of MPP and AHP improved the thermal stability of HDPE/wood flour as observed from the thermogravimetric analysis results and also enhanced the thermal resistance of char layer at high temperature based on scanning electron microscopy observation. 相似文献
18.
Improved interaction between wood and synthetic polymers in wood/polymer composites 总被引：12，自引：0，他引：12
Kristiina Oksman M.Sc. 《Wood Science and Technology》1996,30(3):197-205
Summary This article describes the properties of wood polymer composites consisting of linear low density polyethylene (LLDPE) and wood flour (WF). In an attempt to improve the interfacial adhesion between the matrix and the filler, different compatibilizers were used. The interaction between polymer and wood were studied by comparing LLDPE/WF composites with composites when compatibilizer was added. The experimental measurements were conducted by impact and tensile strength testing and Scanning Electron Microscopy (SEM). The mechanical properties of the composites were improved with SEBS triblock copolymer modified with maleic anhydride and with the ionomer polymer, Surlyn, as compatibilizers. SEM fractography confirmed better adhesion between wood particles and LLDPE matrix when SEBS was present.This study was financed by the Swedish National Board for Industrial and Technical Development (NUTEK) which is gratefully acknowledged 相似文献
19.
JIANG Feng QIN Te-fu 《林业研究》2006,17(4):312-314
Introduction Wood-Plastic Composite (WPC), due to its high stiffness, low density, low cost, environment friendly characteristics such as recyclablity and biodegradability, is gaining more and more interests, both in research and application. However, one… 相似文献