An investigation on the mechanical and dynamic rheological properties of single and hybrid filler/polypropylene composites based on talc and calcium carbonate

Some results of experiments on the mechanical and rheological properties of mineral filled polypropylene were presented. Single filler and hybrid filler composites of talc and calcium carbonate (CaCO₃) were prepared in a co‐rotating twin‐screw extruder. The effect of filler type, filler content, and coupling agent on the mechanical and rheological properties of the polypropylene were studied. The coupling agent was maleic anhydride‐grafted polypropylene (PP‐g‐MA). It was found that the mechanical properties are affected by filler type, filler concentration, and the interaction between filler and matrix. The tensile strength of the composite is more affected by the talc while the impact strength is influenced mostly by CaCO₃ content. The elongation at break of PP/CaCO₃ composites was higher than that of PP/talc composites. The incorporation of coupling agent into PP/mineral filler composites increased the mechanical properties. Rheological properties indicated that the complex viscosity and storage modulus of talc filled samples were higher than those of calcium carbonate filled samples while the tan δ was lower. The rheological properties of hybrid‐filler filled sample were more affected by the talc than calcium carbonate. The PP‐g‐MA increased the complex viscosity and storage modulus of both single and hybrid composites. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Tensile properties of polypropylene flame-retardant composites

The polypropylene (PP) flame-retardant composites filled with aluminum hydroxide (Al(OH)₃), magnesium hydroxide (Mg(OH)₂), zinc borate (ZB), nanometer calcium carbonate (nano-CaCO₃), and polyolefin elastomer (POE) were prepared using a twin-screw extruder, and the tensile properties were measured at room temperature by means of an electronic universal test machine (Model CMT4104) in this paper, to identify the influence of the flame-retardant content on the tensile properties. The results showed that the tensile strength decreased roughly nonlinearly while the tensile elongation at break decreased nonlinearly with increasing the flame-retardant weight fraction. The Young’s modulus and the tensile fracture strength increased nonlinearly with an addition of the flame-retardant weight fraction. The tensile ductility of PP/Al(OH)₃/Mg(OH)₂/ZB/Nano-CaCO₃/POE composite was the best in the three kinds of the composite systems. Moreover, good agreement was showed between the predictions and the measurements of the tensile strength.     

Morphology and mechanical properties of PP/POE/nano‐CaCO3 composites

The mechanical properties including tensile, flexural, and impact of the nanometer on calcium carbonate (nano‐CaCO₃) filled polypropylene (PP)/poly (ethylene‐co‐octene) (POE) composites were measured at room temperature to identify the effects of the POE content on the mechanical properties. It was found that the Young's modulus, tensile strength, and tensile elongation at break decreased nonlinearly while the tensile fracture strength varied slightly with increasing the POE weight fraction; the V‐notched and unnotched Izod impact fracture strength increased nonlinearly with an increase of the POE weight fraction; the flexural modulus and strength decreased roughly linearly with increasing the POE weight fraction. Furthermore, the impact fracture surface of the specimens was observed by means of a scanning electronic microscope to discuss the toughening mechanisms. POLYM. COMPOS., 37:539–546, 2016. © 2014 Society of Plastics Engineers     

Silica‐filled polypropylene composites: The effect of ethylene diamine dilaurate and maleic anhydride grafted polypropylene on mechanical properties,water absorption,morphology, and thermal properties

The effect of two compatibilizers, i.e. ethylene diamine dilaurate (EDD) and maleic anhydride grafted polypropylene (MAPP) on the mechanical properties, water absorption, morphology, and thermal properties of silica‐filled polypropylene (PP/Sil) composites were studied. The results show that the tensile, impact and flexural strengths (up to 2 php), Young's modulus, and elongation at break (Eb) increased with increasing EDD content. However, increasing MAPP content increases the tensile strength, Young's modulus, impact and flexural strengths, and water absorption resistance. At a similar compatibilizer content, EDD exhibits higher Eb, impact and flexural strengths but lowers tensile strength, Young's modulus, and water absorption resistance compared with MAPP. Scanning electron microscopy study of tensile fractured surfaces exhibits the evidence of better silica‐PP adhesion with MAPP and EDD compared with the similar composites but without compatibilizer. Fourier transform infra red spectra provide an evidence of interaction between EDD or MAPP with PP/Sil composites. Termogravimetry analysis results indicate that the addition of EDD or MAPP slightly increases the thermal stability of PP/Sil composites. Differential scanning calorimetry also indicates that PP/Sil composites with EDD or MAPP have higher heat fusion (ΔH_f(com)) and crystallinity (X_com) than similar composites but without compatibilizer. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Mechanical properties and thermal stability of poly(L‐lactide)/calcium carbonate composites

Poly(L ‐lactide) (PLA) was melt‐mixed with micrometer‐sized and nanosized calcium carbonate (CaCO₃) particles before and after modification with calcium stearate. Adhesion between the CaCO₃ particles and the PLA matrix was assessed qualitatively by scanning electron microscopy observation of the fractured surface morphology of the composites. The effect of the incorporation of the CaCO₃ particles on the thermal stability of the PLA‐based composites was quantified by the temperatures corresponding to 5 and 50% of weight loss and the activation energy determined through thermogravimetric analyses of the composites. The tensile strength and modulus values of the composite were improved greatly without a significant loss in the elongation at break when the nanosized CaCO₃ was incorporated up to 30 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

麻纤维增强聚乙烯复合材料的制备及性能研究

通过双螺杆挤出造粒,注塑成型制备了麻纤维增强高密度聚乙烯( HDPE)复合材料,测试了复合材料的力学性能并观察其微观结构,分析了相容剂马来酸酐接枝聚丙烯( PP-g-MAH)的用量和麻纤维的含量对复合材料力学性能的影响.结果表明:PP-g-MAH的加入提高了苎麻/HDPE复合材料的力学性能,并且在PP-g-MAH含量为...     

Thermo-mechanical and mechanical behavior of hybrid isotactic polypropylene glass fiber reinforced composites (GFRC) modified with calcium carbonate (CaCO3)

The study investigates the thermo-mechanical properties of isotactic polypropylene (iPP) hybrid composites in reference to various amounts of particle- and fiber-shaped inorganic fillers. Three grades of hybrid composites were prepared as a function of filler amount: 5, 10, and 20 wt% and different ratios of glass fiber (GF) and calcium carbonate (CaCO₃). The main objective is to describe the relationship between the hybridization efficiency and mechanical performance of polypropylene-based composites. The analysis of the thermo-mechanical properties of the composites shows that both the total amount of the filler and the ratio of GF and CaCO₃ clearly influence the properties of the composites. Hybrid composites with the highest amount of the GF display improved thermo-mechanical stability. The presence of well-dispersed CaCO₃ in the composites was found to improve elongation at break and Vicat softening temperature values. Even though it is glass fiber, which shows higher filler effectiveness and visibly reinforces the composite samples, causing an increase in tensile strength or reinforcing efficiency, replacing up to 50% of this filler with calcium carbonate does not result in a considerable deterioration of the properties of the material.     

碱式碳酸镁阻燃LDPE/EVA的性能研究

用硬脂酸对碱式碳酸镁进行表面改性,加入到低密度聚乙烯(LDPE)和乙烯-醋酸乙烯酯(EVA)的混合物中制备阻燃复合材料。研究了碱式碳酸镁对LDPE/EVA的阻燃及力学性能影响。用扫描电镜(SEM)和热失重(TG)分别表征阻燃复合材料的微观形貌和热性能。结果表明,碱式碳酸镁经过表面改性后,由亲水性变成了亲油性,且当加入的碱式碳酸镁份数为150份时,阻燃复合材料的拉伸强度13.1 MPa,弯曲强度5.0 MPa,冲击强度3.27 kJ/m2,断裂伸长率9.4%,氧指数31.6%。     

THE COMPARISON PROPERTIES OF RECYCLE RUBBER POWDER,CARBON BLACK,AND CALCIUM CARBONATE FILLED NATURAL RUBBER COMPOUNDS

The effects of filler loading on the curing characteristics, swelling behavior, and mechanical properties of natural rubber compounds were studied using a conventional vulcanization system. Recycle rubber powder (RRP), carbon black (CB) (N550), and calcium carbonate (CaCO₃) were used as fillers and the loading range was from 0 to 50 phr. Results show that the scorch time, t ₂, and cure time, t ₉₀, decrease with increase in filler loading. At a similar filler loading, RRP shows shortest t ₂ and t ₉₀ followed by CB and calcium carbonate. The tensile strength, tensile modulus, and hardness increase with increase in CB loading, whereas elongation at break, resilience, and swelling properties show opposite trend. For RRP and calcium carbonate filled natural rubber compounds, the tensile strength increases up to 10 phr and starts to deteriorate at higher filler loading. The other properties such as tensile modulus, hardness, elongation at break, resilience, and swelling percentage show a small change (increase or decrease) with increase in RRP and calcium carbonate loading in natural rubber compounds. Overall results indicate that RRP can be used as a cheapener to replace calcium carbonate in natural rubber compounds where improved mechanical properties are not critical.     

PPS／GF／Nano-CaCO_3三元复合材料的拉伸力学性能

考察了纳米碳酸钙(Nano-CaCO_3)含量及表面处理对玻璃纤维增强聚苯硫醚(PPS／GF)三元复合材料拉伸性能的影响。结果表明：复合材料的拉伸弹性模量、拉伸强度和拉伸断爱强度均有提高；当φ_f小于4％时,拉伸断裂伸长率隨着φ_f的增加而明显增大,然后趋于平缓。经钛酸酯处理的Nano-CaCO_3填充PPS／GF体系的拉伸力学性能略优于经硬脂酸处理的复合体系。     

GB/PP复合材料拉伸性能与介电性能的研究

采用小粒径玻璃微珠(OB)与聚丙烯(PP)熔融共混,研究了GB含量及表面处理对复合材料拉伸性能及介电性能的影响。研究结果表明,与未经表面改性的GB相比,经过偶联剂KH-550和EB-151处理的GB与PP复合后,其拉伸性能得到明显改善;且当GB含量为20%时,经过KH-550处理的GB/PP复合材料的拉伸强度、断裂伸长率和拉伸弹性模量比纯PP的分别提高了8.7%、109.6%和187.0%;复合材料的介电常数随GB含量的增加呈现增大的趋势,经过改性的复合材料的介电常数比未经改性的有所增加,而GB的含量和界面改性对介电损耗的影响不大。     

不同形貌碳酸钙的制备及其对PVC薄膜力学性能的影响

选用偏钒酸铵、聚乙二醇、十六烷基三甲基溴化铵、焦磷酸钠十水和聚乙烯吡咯烷酮作为碳酸钙形貌控制剂,以氯化钙和碳酸钠为原料,用氯化法制备得到了片状、菱形、棒状、球状和立方体状5种不同形貌碳酸钙微粒,并研究不同形貌碳酸钙颗粒形态对软质聚氯乙烯（PVC）薄膜力学性能的影响。结果表明,不同形貌碳酸钙均提高了PVC薄膜的力学性能,PVC薄膜拉伸强度和断裂伸长率均提高显著;其中,棒状形貌碳酸钙对PVC薄膜力学性能的提高效果最好,拉伸强度达到了27.11 MPa;菱形碳酸钙改性PVC薄膜的断裂伸长率最高,为98.23 %。     

碳纤维改性HA/PMMA生物复合材料力学性能的研究

采用原位合成与溶液共混相结合的方法,制备了短切碳纤维增强纳米羟基磷灰石(HA)/聚甲基丙烯酸甲酯(PMMA)生物复合材料。研究了碳纤维的含量和长度对HA/PMMA复合材料结构和力学性能的影响。采用万能材料试验机和扫描电子显微镜对复合材料的力学性能及断面的微观形貌进行了测试和表征。结果表明:碳纤维在HA/PMMA复合材料中分布均匀,有效提高了复合材料的力学性能;碳纤维含量为4%时,复合材料的拉伸强度、弯曲强度、压缩强度和弹性模量等均达到最大值;复合材料的断裂伸长率随碳纤维含量的增加而减小;当碳纤维含量一定时,随其长度的增加,复合材料的拉伸强度、弯曲强度和弹性模量均增加,但断裂伸长率降低。     

EVA改性PE共混物力学性能和流变性能的研究

讨论了橡塑共混比、填料用量等因素对乙烯－醋酸乙烯共聚物（ＥＶＡ）改性ＰＥ共混物力学性能和流变性能的影响。试验结果表明，ＥＶＡ弹性体的加入降低了共混物的拉伸强度，提高了扯断伸长率及共混物熔体的流动性；活性碳酸钙的加入使共混物的拉伸强度、扯断伸长率和流动性下降；ＨＤＰＥ的加入提高了共混物的拉伸强度，但扯断伸长率和流动性下降。     

纳米碳酸钙复合淀粉基薄膜的制备及力学表征

实验采用分步改性再共混的方法,用流延工艺制备碳酸钙复合淀粉基薄膜,探究碳酸钙助剂对淀粉基薄膜性能的影响。实验结果表明:以碳酸钙作为助剂,选择添加0.2 g的碳酸钙(即占淀粉添加质量的4%) 80℃加热搅拌1 h,继续升温至90℃,共混2 h为最佳条件;此时的拉伸强度、弹性模量、断裂伸长率分别为6.091 8 MPa、384.997 5 MPa、15.172 4%。     

聚乳酸/无机填料复合材料结构与性能的研究

采用密炼器熔融共混法,将聚乳酸(PLA)分别与碳酸钙(CaCO3)、蒙脱土(MMT)及滑石粉(Talc)共混制备成生物降解复合材料,研究了PLA/无机填料共混物的力学性能、断面微观结构及结晶性能。结果表明:CaCO3、MMT和Talc均降低了PLA的断裂伸长率;Talc和CaCO3对PLA的拉伸强度影响不大,MMT明显降低了PLA的拉伸强度;Talc和CaCO3相对MMT在PLA基体中的分散较均匀;CaCO3和MMT改善PLA结晶性能的效果不明显,而Talc大大提高了PLA的结晶性能使,PLA的结晶温度下降约20℃结,晶度提高近3%。     

双组分聚氨酯胶粘剂的研制

以改性聚醚多元醇、MDI预聚体和改性轻质碳酸钙为原料,制备了双组分聚氨酯胶粘剂.实验结果表明,改性CaCO3对PU胶具有增强作用,在CaCO3添加量为10％左右时,其增强效果最好,拉伸强度达11MPa;当CaCO3深加量为20％时断裂伸长率达到最大值165％;PU／CaCO3复合体系中CaCO3颗粒分散均匀.     

花生壳粉/聚丙烯复合材料的研究

利用双螺杆挤出工艺对花生壳粉填充改性聚丙烯(PP)进行了研究。结果表明。加入花生壳粉后．复合材料的弯曲强度、硬度、维卡软化温度、拉伸强度和断裂伸长率均有所提高。但其加工流动性能和冲击强度有所下降。在花生壳粉含量为30％时，复合材料的综合性能较优。     

Effect of carbon nanotube‐supported β nucleating agent on the thermal properties,morphology, and mechanical properties of polyamide 6/isotactic polypropylene blends

A new kind of β nucleating agent, multi‐wall carbon nanotube (MWCNT)‐supported calcium pimelate was introduced into polyamide 6 (PA 6)/isotactic polypropylene (iPP; 10/90 by weight) blend and the thermal properties, morphology, and mechanical properties were investigated. The results showed that β‐iPP appeared at low content of MWCNT‐supported calcium pimelate which surmounted the α‐nucleating effect of PA 6 for iPP, and the content of β‐iPP increased with increasing content of MWCNT‐supported calcium pimelate. The impact strength, elongation at break, and flexural modulus were improved with increasing content of MWCNT‐supported calcium pimelate without significantly deteriorating the tensile strength. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of Durian Seed Flour on Processing Torque,Tensile, Thermal and Biodegradation Properties of Polypropylene and High Density Polyethylene Composites

Composites containing various percentage of durian seed flour (DSF) in the polypropylene (PP) and high density polyethylene (HDPE) have been compounded using an internal mixer. The processing torque, tensile, thermal and biodegradation properties have been determined. The incorporation of DSF increases stabilization torque and had adversely affected the mechanical properties by reducing the tensile strength and elongation at break, while the elastic modulus is increased, as starch content increases. At similar filler content, DSF filled PP showed higher tensile strength and elastic modulus, while lower in elongation at break than DSF-filled HDPE. The scanning electron microscopy (SEM) of tensile fracture specimens revealed good adhesion and dispersion of the DSF granules in the polymer matrix. However, the SEM results showed agglomeration of the DSF at higher filler content in the polymer and hence revealed poor wetting between DSF granules and polymer. The TGA results showed that both of the composites systems with higher filler content have higher initial degradation temperatures, T₀, degradation temperatures, T_deg and total weight loss. A simple biodegradability test conducted on each composite system shows that composites are subjected to biodegradation, judging by the significant increase in carbonyl and hydroxyl index of the composites after the test.