白炭黑和mPE增韧PP竹塑复合材料的性能及其机理

本研究以60目竹纤维粉为填充材料,聚丙烯为塑料基体,硅烷为偶联剂,分别以不同含量无机粒子白炭黑和弹性体茂金属聚乙烯(mPE)为增韧剂,模压成型制备了竹塑复合材料。并对竹塑复合材料力学性能和吸水性能进行测试,对比了不同增韧剂的增韧效果。结果表明:当白炭黑添加量为6%时,复合材料的冲击强度、弯曲强度、拉伸强度分别提高99%、424%和114%,吸水率提高41%;当mPE添加量为4%时,复合材料的冲击强度、弯曲强度、拉伸强度分别提高139%、168%和151%,吸水率降低了41%。白炭黑和mPE对PP竹塑复合材料均具有较好的增韧效果,综合考虑力学性能和吸水性能,mPE是PP竹塑复合材料较理想的冲击改性剂。结合多种测试结果表明:添加的增韧剂是通过与基体材料进行化学反应降低复合材料内部极性而实现增强增韧。     

废印刷电路板非金属粉填充聚丙烯的实验

采用熔融共混方法制备了废印刷电路板非金属粉/聚丙烯复合材料,并通过非金属粉润湿性能和缺口冲击断面形貌观察,分析研究了非金属粉添加对聚丙烯复合材料力学性能的影响。结果表明,非金属粉可以同时改善非金属粉/聚丙烯复合材料的拉伸、弯曲、低温冲击性能,但室温冲击性能降低;其中拉伸强度、拉伸模量、弯曲强度、弯曲模量、低温冲击强度最大增幅分别为16.3%、41.5%、63.5%、100%、45.7%;废印刷电路板非金属粉可作为聚丙烯的增强增韧填料。     

功能化石墨烯/埃洛石纳米管对聚丙烯的协同强韧化改性研究

以功能化氧化石墨烯(GO)-埃洛石纳米管(HNTs)杂化材料(GO@HNTs)为纳米填料,以聚丙烯(PP)为基体,通过熔融共混法制备了不同GO@HNTs 含量的GO@HNTs/PP纳米复合材材料,并对所得杂化填料和PP纳米复合材料的结构与性能进行系统研究。研究结果表明,功能化GO与HNTs之间存在化学相互作用,二者之间形成的“屏障效应”抑制了彼此在PP基体中的团聚。仅添加0.5%GO@HNTs杂化纳米填料后,PP复合材料的拉伸强度和冲击强度分别较纯PP提高了17.5%和80.4%,与单独添加相同含量的GO或HNTs所得复合材料的力学性能相比,GO@HNTs杂化纳米填料对PP基体具有明显的协同增强增韧改性作用。与纯PP相比,GO@HNTs/PP试样表现出更高的储能模量、损耗模量和玻璃化转变峰值。由于GO@HNTs的“异相成核效应”和“物理热阻效应”,有效提高了PP纳米复合材料的结晶温度、熔融温度、结晶度和耐热分解温度。     

超微竹炭增强聚丙烯复合材料的制备与性能

为提高聚丙烯(PP)基复合材料的力学性能和热学性能,将不同质量分数的超微竹炭(UFBC)作为增强体引入聚丙烯,通过熔融挤出及注塑成型工艺制备UFBC/PP复合材料。利用SEM和DSC分析、力学强度和吸湿性测试等手段综合表征复合材料性能。结果表明:UFBC与PP基体间界面结合紧密;UFBC的添加对PP复合材料的力学强度有较好的增强效果:UFBC质量分数为30wt%时,UFBC/PP复合材料的拉伸强度和弯曲强度达到较大值,分别为26MPa和54MPa,较纯PP分别提高了9%和18%,UFBC/PP复合材料的耐湿性仍保持较佳水平,吸湿率均小于0.1%;UFBC质量分数为40wt%时,熔融温度提高了3.1℃;UFBC质量分数为50wt%时,UFBC/PP复合材料的结晶温度提高了10.8℃。UFBC的添加有效促进了UFBC/PP复合材料的结晶,改善了其加工性。     

废印刷电路板非金属粉增强及磨碎玻璃纤维增强聚丙烯力学性能

分别用废印刷电路板(PCB)非金属粉、磨碎玻璃纤维作为增强材料,采用熔融共混方法制备了聚丙烯(PP)基复合材料,并通过其力学性能试验和缺口冲击断面、废PCB非金属粉、磨碎玻璃纤维的形貌观察,分析研究了两种增强材料及表面改性对复合材料力学性能的影响。实验结果表明：废PCB非金属粉/PP复合材料力学性能得到了明显提高,其中拉伸强度、拉伸模量、弯曲强度和弯曲模量最大增幅分别为28%、41%、86%和133%;废PCB非金属粉与磨碎玻璃纤维都能作为PP增强填料,但其韧性降低;表面改性对废PCB非金属粉/PP复合材料力学性能的影响不大,但是对磨碎玻璃纤维/PP复合材料力学性能的影响大;废 PCB非金属粉/PP复合材料综合力学性能高于磨碎玻璃纤维/PP复合材料,可代替磨碎玻璃纤维作为PP基复合材料的增强填料,不仅可以减少环境污染,实现资源再利用,而且大大降低复合材料成本。     

回收汽车用废旧塑料制备复合板材的力学性能

以汽车内饰用废弃塑料为主要原料,粉碎后通过添加新的接枝改性聚丙烯短切玻璃纤维制备出复合板材,研究了改性PP和短切玻纤对材料力学性能的影响.结果表明,改性PP的加入有利于改善材料的成形性能.添加新的改性聚丙烯后,复合材料的压缩强度和压缩模量增大,随着改性PP含量的提高,弯曲强度大幅提高而弯曲模量稍有降低;随着短切玻璃纤维含量的提高,材料的弯曲强度及弯曲模量均明显提高.     

聚乙烯醇交联改性对天然纤维增强聚丙烯复合材料性能的影响

采用聚乙烯醇(PVA)交联对洋麻(KF)增强聚丙烯(PP)、棕榈(PF)增强聚丙烯(PP)复合材料进行改性,通过模压成型工艺制备KF/PP和PF/PP复合材料。研究不同交联方法对复合材料的结构和性能的影响,采用SEM、DMA等技术研究了改性对复合材料的界面结合及力学性能影响。结果表明:PVA协同偶联剂交联改性对天然纤维/PP复合材料的综合改性效果最好,当用5%PVA+3%偶联剂对KF/PP改性时,KF/PP复合材料的弯曲强度提升25.2%,弯曲模量提升35.49%,剪切强度提升28%,分别达到了50.90 MPa、5.76 GPa、5.4MPa。当用5%PVA+2%偶联剂对PF/PP改性时,PF/PP复合材料的弯曲强度提升31.46%,弯曲模量提升27.07%,剪切强度提升21.75%,分别达到44.33MPa、2.32GPa、5.18MPa。改性后KF/PP、PF/PP复合材料的含水率分别下降了46.89%、10.63%,吸水率分别下降了8.57%、6.12%。KF/PP改性后储能模量提高20.93%,PF/PP改性后Tg值由90.1℃上升到113.8℃。SEM表明:PVA协同偶联剂交联改性有效改善了纤维与PP间的粘结,纤维与PP间的界面结合得到改善。     

硼酸锌含量对麦秸秆/PP复合材料耐霉菌腐蚀性能的影响

为探讨防霉剂硼酸锌对麦秸秆/聚丙烯(PP)复合材料耐霉菌腐蚀性能的影响,对添加不同含量硼酸锌的麦秸秆/PP复合材料进行了霉菌加速腐蚀实验。测试其腐蚀后的力学性能、颜色变化和吸水性,采用FTIR分析其官能团的变化,采用体视显微镜观察并分析复合材料表面霉菌生长情况及表面微观结构。结果表明:硼酸锌对麦秸秆/PP复合材料耐腐蚀性能有较好的改善作用,硼酸锌最佳添加量为2wt%,麦秸秆/PP复合材料腐蚀后表面霉菌生长较少,其弯曲强度、弯曲弹性模量、拉伸强度和冲击强度比不添加硼酸锌分别提高6.5%、50.2%、6.8%和11.1%,吸水率和色差值降低23.9%和30.7%。含量为2wt%的硼酸锌能够有效阻止霉菌菌丝腐蚀麦秸秆/PP复合材料的麦秸秆纤维素和半纤维素,而硼酸锌含量较高时会影响复合材料的界面,导致界面处麦秸秆纤维更易受霉菌腐蚀作用。     

PP/HGMS复合材料真空热压成型及性能研究

以聚丙烯(PP)为基体,以高性能空心玻璃微珠(HGMS)为填充体,通过真空热压成型法制备聚丙烯/空心玻璃微珠复合材料。研究了HGMS填充体积分数对复合材料的密度、拉伸强度、压缩强度、剪切强度和吸水率的影响,分析了复合材料断口的微观形貌。结果表明,采用真空热压成型法能够制备性能优良的PP/HGMS复合材料。当HGMS体积分数达到50%时,复合材料的密度降低到0.645 g/cm~3,并且具有35.64 MPa的压缩强度和1.41%的吸水率。     

PP/POE/高岭土三元复合材料的力学及热性能

研究了高岭土和乙烯-辛烯共聚物弹性体(POE)填充聚丙烯(PP)制备的PP/POE/高岭土三元复合材料的力学和热力学性能。结果表明,POE和高岭土不能提高PP的拉伸强度,但高岭土可以显著提高PP/POE的杨氏模量。POE降低了PP的弯曲强度和弯曲模量,但PP/POE/高岭土三元复合材料的弯曲强度和弯曲模量显著高于PP/POE和PP。POE和高岭土可以显著提高PP的冲击强度,当高岭土和POE的填充份数分别为10份和5份时,PP/POE/高岭土复合材料的冲击强度最大。高岭土的添加可以提高PP的结晶温度,加快PP的结晶速率,促进PP的异相成核。合适含量的高岭土可以提高PP的熔融温度,改善PP的耐热性能。     

Development of a new inexpensive green thermoplastic composite and evaluation of its physico-mechanical and wear properties

In the present study an attempt has been made to use turmeric spent (TS) as reinforcing filler to fabricate polypropylene (PP) green composite for load bearing and tribological applications. PP/TS composites were fabricated using varying amounts of TS viz, 10%, 20%, 30% and 40% (w/w) by twin screw extrusion method. The fabricated PP green composites were evaluated for physico-mechanical and tribological properties. Experimentally obtained tensile values were compared with theoretically predicted values using different theoretical models. Tensile modulus of composites increased from 1041 to 1771 MPa with the increase in filler addition from 0 to 40 wt.%. Flexural strength and flexural modulus of composites were improved after incorporation of TS into PP matrix. The water absorption characteristics of composites were determined. The effect of abrading distances viz., 150, 300, 450, and 600 m and different loads of 23.54 and 33.54 N at 200 rpm on the abrasive wear behaviour were studied using dry sand/rubber wheel abrasive test rig. The TS filler lowered the abrasion resistance of PP/TS composites. The wear volume loss and specific wear rate as a function of abrading distance and load were determined. The surface morphology of tensile fractured green composites and their worn surface features were examined under scanning electron microscope.     

Mechanical behaviour of agro-residue reinforced poly(3-hydroxybutyrate-co-3-hydroxyvalerate), (PHBV) green composites: A comparison with traditional polypropylene composites

Novel green composites were successfully fabricated by incorporating agro-residues as corn straw (CS), soy stalk (SS) and wheat straw (WS) into the bacterial polyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, by melt mixing technique. Effects of these biomass fibers on mechanical, thermal, and dynamic mechanical properties of PHBV were investigated. A comparative study of biomass fiber-reinforced polypropylene composite systems was performed. The tensile and storage modulus of PHBV was improved by maximum 256% and 308% with the reinforcement of 30 wt.% agricultural byproducts to it. For equal amounts of (30%) biomass fibers, tensile and flexural modulii of PHBV composites showed much higher values than corresponding PP composites. Alkali treatment of wheat straw fibers enhanced strain @ break and impact strength of PHBV composites by ∼35%, hardly increasing strength and modulus compared to their untreated counterparts. DMA studies indicated better interfacial interaction of PHBV with the biomass fibers than PP. Scanning electron microscopy (SEM), used to study the morphology of composites, also revealed similar outcomes.     

Study on the mechanical properties,environmental effect,degradation characteristics and ionizing radiation effect on silk reinforced polypropylene/natural rubber composites

Natural silk fiber (20%) reinforced polypropylene (PP) composites were prepared by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, impact strength and hardness of the prepared composite were found 54.7 MPa, 1826.2 MPa, 58.3 MPa, 3750.7 MPa, 17.6 kJ/m² and 95 shore A, respectively. To improve the biodegradable character of the composite, natural rubber (NR) was blended (10%, 25%, 50% by weight) with PP. It was found that the mechanical properties of the composite decrease with increasing NR in PP (except IS which increased rather decreasing). Environmental effect on the composite and degradation in various media were investigated in this study. Gamma radiation was used to increase the mechanical properties of the prepared composites. Increase in TS and BS were maximum at 250 krad dose for silk fiber/PP, silk fiber/PP:NR (90:10), silk fiber/PP:NR (75:25) and silk fiber/PP:NR (50:50) composites.     

碳纤维三维编织复合材料的结构对拉伸和弯曲性能的影响

研究了碳纤维四步法三维四向、三维五向编织结构复合材料的拉伸和弯曲性能,以及结构参数-编织角的变化对其拉伸和弯曲性能的影响,并与层合复合材料作了对比性研究.结果表明,三维编织复合材料具有良好的力学性能,其拉伸强度可达810MPa、拉伸模量可达95.6GPa,弯曲强度可达829.03MPa、弯曲模量可达67.5GPa.同时,编织角和编织结构对复合材料性能有较大的影响.随着编织角的增大,复合材料的拉伸、弯曲强度和模量均减小;三维五向结构的拉伸、弯曲强度和模量均高于四向结构;在纤维体积含量相近的情况下,通过对编织角的设计,可以设计三维编织复合材料的性能.     

PP-g-Si与KH550对聚丙烯/滑石粉体系的增容效果

硅烷接枝聚丙烯（ＰＰ－ｇ－Ｓｉ）对聚丙烯／滑石粉（ＰＰ／Ｔａ）混合体系有一定的增容作用,可使复合材料的力学性能得以提高,占复合材料总质量３．５％的ＰＰ－ｇ－Ｓｉ（相当于含硅烷０．２％）对ＰＰ／Ｔａ体系的增容效果与含０．８％（质量分数）的ＫＨ５５０的增容效果相当,ＫＨ５５０对复合材料中聚丙烯（ＰＰ）的结晶熔融行为基本上无影响。而ＰＰ－ｇ－Ｓｉ能进一步使材料中ＰＰ的结晶峰温和熔融峰温提高。     

Improvement of impact property of natural fiber–polypropylene composite by using natural rubber and EPDM rubber

In this research, vetiver grass was used as a filler in polypropylene (PP) composite. Chemical treatment was done to modify fiber surface. Natural rubber (NR) and Ethylene Propylene Diene Monomer (EPDM) rubber at various contents were used as an impact modifier for the composites. The composites were prepared by using an injection molding. Rheological, morphological and mechanical properties of PP and PP composites with and without NR or EPDM were studied. Adding NR or EPDM to PP composites, a significant increase in the impact strength and elongation at break is observed in the PP composite with rubber content more than 20% by weight. However, the tensile strength and Young’s modulus of the PP composites decrease with increasing rubber contents. Nevertheless, the tensile strength and Young’s modulus of the composites with rubber contents up to 10% are still higher than those of PP. Moreover, comparisons between NR and EPDM rubber on the mechanical properties of the PP composites were elucidated. The PP composites with EPDM rubber show slightly higher tensile strength and impact strength than the PP composites with NR.     

Producing toughened PP/HA-LLDPE ternary bio-composite using a two-step blending method

The mechanical and morphological properties of polypropylene/hydroxyapatite/linear low density polyethylene ternary bio-composites which were produced by blending of polypropylene (PP), hydroxyapatite, modified and unmodified linear low density polyethylene (LLDPE) were studied. In this research, effects of LLDPE weight percent, modification of PP/LLDPE interface by a high crystallizable high density polyethylene, and the method of blending on tensile strength, Young’s modulus and impact absorbed energy of composites were investigated. Results of mechanical tests showed that by adding LLDPE to these composites, ultimate tensile strength and Young’s modulus of the composites dropped slightly, while their impact strength was increased significantly. Mechanical properties of composites were improved by modification of PP/LLDPE interface and changing from one-step blending to two-step blending. However, for the composites produced by two-step blending, by adding modified LLDPE (15 wt.%), the impact strength was 90% more than that of pure PP/HA composites. Fractography of the surface fractures of the impact samples for both types of composites were performed using a scanning electron microscope (SEM). Two different toughening mechanisms of these composites were distinguished by drawing a schematic sketch of the mechanisms.     

汉麻纤维表面改性对其增强聚丙烯复合材料性能及挥发性有机化合物释放影响

通过非织造-热压工艺制备了汉麻纤维增强聚丙烯（HF/PP）复合材料。采用热重-质谱联用仪（TG-MS）研究了HF/PP复合材料的挥发性有机化合物（Volatile organic compounds,VOC）释放来源及汉麻经聚乙烯醇（PVA）改性和尿素改性对HF/PP复合材料VOC释放的影响,同时研究了两种改性方法对HF/PP复合材料热学性能和力学性能的影响。结果表明：HF/PP复合材料中的VOC主要来源于汉麻纤维,改性后的HF/PP复合材料力学性能相比未处理的均有不同程度的提升,尿素改性后,HF/PP复合材料的拉伸强度和弯曲强度达到最大值,较未处理时分别提升了19.32%和15.04%。PVA改性后,HF/PP复合材料的拉伸模量、弯曲模量和剪切强度达到最大值,相比未改性时分别提升了17.72%、15.94%和24.72%。改性后HF/PP复合材料热稳定性能和VOC释放相较未处理时均得到了优化：PVA改性后HF/PP复合材料热稳定性最优,三个阶段总活化能较未处理时提高了121.99%,达到了392.56 kJ·mol^-1,并且HF/PP复合材料热稳定性与界面性能密切相关;尿素及PVA改性后HF/PP复合材料的总VOC（TVOC）释放量相较未处理时均降低。     

Vetiver–polypropylene composites: Physical and mechanical properties

Injection molded vetiver–polypropylene (PP) composites at various ratios of vetiver content and vetiver length were prepared. When compared to PP, vetiver–PP composites exhibited higher tensile strength and Young’s modulus but lower elongation at break and impact strength. An increase in vetiver content led to an increase in viscosity, heat distortion temperature, crystallization temperature, and Young’s modulus of the composites. On the other hand, the decomposition temperature, tensile strength, elongation at break, and impact strength decreased with increasing vetiver content. The chemical treatment of the vetiver grass improved the mechanical properties of the composites.     

新型的高杀菌纳米二氧化钛/聚丙烯复合材料的结构和物理特性研究

基于一种新型的纳米二氧化钛(TiO₂)粉体,利用熔体共混方式制备了纳米TiO₂/聚丙烯(PP)复合材料,研究了复合材料的相分散结构、结晶特性、力学性能、杀菌性能和流动性能。结果发现:新型纳米TiO₂在聚丙烯中有较好的分散度,绝大多数纳米TiO₂在聚丙烯中的聚集体尺寸接近于100纳米;新型纳米TiO₂对聚丙烯有一定的结晶成核作用,但并不能提高结晶度;复合材料的力学性能随纳米TiO₂含量的增加呈现出拉伸强度下降,伸长率降低,模量和冲击强度上升的趋势。2％纳米TiO₂含量的聚丙烯复合材料的综合物理机械性能较好。新型纳米TiO₂填充到PP中可以起到良好的抗菌杀菌作用,但也在一定程度上使聚丙烯发生氧化降解,进而导致纳米TiO₂/聚丙烯复合材料的流动性略优于纯聚丙烯。