PLA/橡实淀粉/二聚脂肪酸聚酰胺复合材料研究

采用熔融挤出法制备了聚乳酸(PLA)/橡实淀粉(AS)/二聚脂肪酸聚酰胺(DAPA)三元复合材料。在保持PLA与AS质量比不变的情况下(60/40),研究了DAPA含量对复合材料的力学性能、疏水性能、热性能和熔体流动速率(MFR)的影响。研究表明,随DAPA添加量的增加,复合材料的疏水性和MFR逐渐提高,而复合材料的拉伸、弯曲强度呈先增大后减小的趋势,且当DAPA质量分数为2%时,复合材料具有最优的力学性能;DAPA的加入增强了PLA与AS的界面相容性,但在一定程度上降低了复合材料的玻璃化转变温度和初始热稳定性。     

二聚脂肪酸增韧改性聚乳酸/橡实淀粉共混体系的研究

通过熔融挤出法制备了二聚脂肪酸（DA）改性聚乳酸（PLA）/橡实淀粉（AS）共混体系,并在保持PLA和AS质量比不变（60/40）,仅DA含量变化的情况下,通过扫描电子显微镜、动态热机械分析仪和同步热分析仪等测试手段对共混体系的力学性能、疏水性能、热性能和熔体流动性进行了测试分析。结果表明,随着DA含量的增加,共混体系的疏水性和熔体流动性能逐渐增强,而共混体系的拉伸、弯曲强度则呈逐渐降低的趋势;DA的加入显著提高了PLA基体材料的韧性,并在一定程度上降低了共混体系的玻璃化转变温度和初始热稳定性。     

马来酸酐接枝共聚物增容聚乳酸/改性淀粉复合材料的制备与性能研究

采用熔融共混方法制备聚乳酸/改性淀粉复合材料。研究了不同含量的马来酸酐接枝共聚物对聚乳酸/改性淀粉复合材料力学性能的影响,并且采用差示扫描量热(DSC)仪和扫描电子显微镜(SEM)对复合材料的微观结构进行分析。结果表明,马来酸酐接枝共聚物的加入改善了聚乳酸与淀粉的相容性,提高了复合材料的力学性能,添加量为0.5份时复合材料的拉伸强度提高了61.6%,断裂伸长率提高了53.1%,弯曲强度提高了104.7%,同时还能提高复合材料的热变形温度和耐水性;改性淀粉与聚乳酸两相紧密连接。     

阻燃竹纤维增强聚乳酸复合材料降解性能的研究

以聚乳酸(PLA)为原料,乙酰柠檬酸三丁酯(ATBC)为增塑剂,利用竹纤维作为增强体,加入聚磷酸铵/淀粉/甲酰胺、双氰胺(APP/TS/FD)混合膨胀型阻燃剂,制备阻燃型竹纤维/PLA复合材料,通过分析土埋、热老化两种条件下,复合材料表面形貌、燃烧性能、热性能、吸水性能、力学性能的变化,研究竹纤维增强PLA复合材料的降解性能。研究表明,在热老化情况下,复合材料的力学性能变化更为明显,在80℃下热老化12天后复合材料的拉伸强度和弯曲强度分别降低了86.6%和77.1%,而土埋3个月后的拉伸强度和弯曲强度分别降低了71.9%和61.8%,处理前后复合材料的燃烧性能和热性能均无明显变化。     

橡实粉/聚乳酸生物可降解复合材料的制备和性能研究

以橡实粉与聚乳酸(PLA)为原料,采用双辊混炼法制备橡实粉/聚乳酸生物可降解复合材料。分析橡实粉经不同处理后对复合材料的力学性能、吸水性能、热性能的影响。研究表明:橡实粉经处理后,复合材料的力学性能得到提高,其中酰化处理的橡实粉复合材料拉伸强度最高,吸水性能最低;热降解结果显示经酰化处理及微波辐射处理的橡实粉复合材料稳定性增强。热降解性能结果显示420℃以后,橡实粉经过酰化和微波辐射处理的复合材料残留物明显减少。     

HDPE/CNTs复合材料的制备及性能研究

以高密度聚乙烯(HDPE)为基体、碳纳米管(CNTs)为导热填料,通过熔融共混法和溶液共混法制备了HDPE/CNTs导热复合材料;研究了CNTs添加量和尺寸对复合材料力学性能、热导率、维卡软化温度和熔体流动速率的影响,并对比了两种制备方法对复合材料力学性能和热导率的影响。结果表明:随着CNTs用量的增加,复合材料的拉伸强度、弯曲强度和热导率均明显提高;直径大的CNTs更有利于复合材料性能的提升;加入10%的CNTs后,复合材料的拉伸强度、弯曲强度和热导率分别提高了33.43%、36.31%和52.59%(测试温度60℃);采用熔融共混法制备的复合材料的性能提高更明显。     

聚丁二酸丁二醇酯/淀粉复合材料制备与性能研究

采用熔融共混法制备了聚丁二酸丁二醇(酯PBS)/淀粉复合材料。用扫描电镜、宽角X-射线衍射、差示扫描量热、热重分析等方法研究了复合材料的力学性能、微观形貌、结晶性能和热稳定性。结果表明:复合材料的拉伸强度、断裂伸长率和冲击强度随淀粉含量的增加而降低,而硬度、拉伸模量和弯曲模量则随淀粉含量的增加而提高;PBS和淀粉间的界面明显,断裂面上存在淀粉脱落的痕迹;淀粉的加入并未影响PBS的晶型;随着淀粉含量的增加,PBS的结晶和熔融温度均向低温方向移动;PBS和淀粉在各自的温度区域产生了热降解,随着淀粉含量的增加复,合材料的热稳定性逐渐降低。     

聚丁二酸丁二酯/丙三醇增塑淀粉的制备及性能

用丙三醇增塑玉米淀粉制备热塑性淀粉,采用熔融共混法制备了聚丁二酸丁二酯(PBS)/丙三醇增塑玉米淀粉(GTPS)复合材料。用红外光谱(FTIR)、宽角-X射线衍射(WXRD)、扫描电镜(SEM)等方法研究了复合材料的相容性、结晶性能、力学性能、微观形貌及降解性能。结果表明:加入淀粉未改变PBS的晶型;丙三醇对淀粉的塑化只发生在淀粉的非晶区;加入淀粉,PBS的拉伸强度、断裂伸长率降低,冲击强度上升;随丙三醇含量上升,体系的力学性能下降。     

聚碳酸亚丙酯/热塑性氧化淀粉的流变、形态和性能

采用熔融共混的方法制备了马来酸酐接枝聚碳酸亚丙酯(PPCMA)/热塑性淀粉(TPS)、PPCMA/热塑性氧化淀粉(TPOS)和PPCMA/ DL-TPOS(铝酸酯预处理的TPOS)复合材料,研究淀粉的氧化以及偶联剂的加入对PPC复合材料流变、形态和性能的影响。加入淀粉后的PPC复合材料拉伸强度有较大提高,红外光谱结果显示淀粉和PPCMA之间形成了氢键作用,这可能是力学性能提高的主要原因;热塑性氧化淀粉与PPCMA基材的界面相容性提高,PPCMA/TPOS复合材料的力学性能、储能模量、损耗模量和复数黏度均高于PPCMA/TPS复合材料;铝酸酯对TPOS的预处理促进了TPOS在PPCMA中的分散,提高了复合材料的拉伸强度,在PPCMA/DL-TPOS体系中,当DL-TPOS含量为40%(质量分数)时拉伸强度达到最大值,与PPCMA相比,提高了4.6倍。     

PE-g-MAH增容改性LDPE/橡实壳纤维复合材料的研究

采用熔融挤出法制备了低密度聚乙烯(LDPE)/橡实壳纤维(AS)木塑复合材料.研究了增容剂聚乙烯接枝马来酸酐(PE-g-MAH)对LDPE/AS木塑复合材料的影响.结果表明,PE-g-MAH是一种优良的增容剂,当其质量分数为5%时,LDPE/AS复合材料的拉伸强度比未添加时提高77.6%,弯曲强度提高83.8%,缺口冲击强度基本保持在5.0 kJ/m2.SEM分析表明,PE-g-MAH改善了AS与LDPE基体材料的相容性.DMA和DSC测试表明,PE-g-MAH能有效改善两相之间的界面相容性,并从根本上改善LDPE基体材料的性能.     

Effect of PDMS content on waterproofing and mechanical properties of geopolymer composites

The present study mainly studies the effect of polydimethylsiloxane (PDMS) content on the waterproofing and mechanical properties of geopolymer composites. Firstly, hydrophobic modified geopolymer composites (HM-GC) were prepared by adding PDMS during the mixing process. Secondly, the surface wettability characteristics, water absorption, uniaxial compressive and tensile properties of HM-GC were investigated. The effect of PDMS content on the waterproofing and mechanical properties was further discussed. Finally, considering the waterproofing and mechanical properties, the optimal PDMS content was proposed. The results showed that with increasing PDMS content, the contact angle of geopolymer composites rapidly increase at first and then stabilizes. The geopolymer composites with 4% and 5% PDMS content exhibit overhydrophobic surface wettability. In addition, the water absorption gradually decreases with increasing PDMS content, indicating an improvement in the waterproofing ability. The incorporation of PDMS can enhance the compressive properties of geopolymer composites while reducing the tensile properties. Comprehensively considering the waterproofing and mechanical properties, it is reasonable to select 4% as the optimal PDMS content used in practical marine engineering.     

PVC基木塑复合材料力学性能的研究

利用胺类改性剂M处理木粉,研究了改性剂M和力学性能改性剂丙烯腈-苯乙烯共聚(物AS)的用量对聚氯乙(烯PVC)基复合材料力学性能的影响。结果表明:随着改性剂M用量的增加,复合材料的拉伸强度、无缺口冲击强度、弯曲强度以及弯曲模量都呈先上升后下降的趋势,且当M用量略大于2%时达到最大值;随着AS用量的增加,复合材料的拉伸强度、弯曲强度及弯曲模量都呈逐渐上升的趋势,无缺口冲击强度呈逐渐下降的趋势到,8%时趋于平缓。     

Studies on the Physicomechanical Properties of Sodium Periodate Oxidized Jute Reinforced Polypropylene (PP) Composites

In the present work, effects of oxidation and fiber content (from 20 to 35 wt. %) on the physicomechanical properties of jute-polypropylene (PP) composites were studied. Mechanical properties (tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus, and charpy impact strength) were measured for all raw and oxidized jute-PP composites. Improved mechanical properties were obtained for oxidized jute-PP composites. Interfacial adhesion and bonding between the fiber and PP matrix were investigated by scanning electron micrograph analysis. Improved interfacial interactions and reduced water absorption were found for oxidized jute-PP composites. Water absorption tests of all composites were also performed.     

Polypropylene and potato starch biocomposites: Physicomechanical and thermal properties

To determine the possibility of using starch as biodegradable filler in the thermoplastic polymer matrix, starch‐filled polypropylene (PP) composites were prepared by extrusion of PP resin with 5, 10, 15, and 20 wt % of potato starch in corotating twin‐screw extruder. The extruded strands were cut into pellets and injection molded to make test specimens. These specimens were tested for physicomechanical properties such as tensile and flexural properties, Izod impact strength, density, and water absorption. These PP composites were further characterized by melt flow index (MFI), vicat softening point (VSP), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) techniques. It was found that, with increase in starch content, tensile modulus, flexural strength, and flexural modulus of the PP composites increased along with the increase in moisture, water absorption, and density, while retaining the VSP; but, tensile strength and elongation, impact strength, hardness, and MFI of the PP composites also decreased. DSC analysis of the PP composite revealed the reduction in melting temperature, heat of fusion, and percentage of crystallization of PP with increase in starch content. Similarly, TGA traces display enhanced thermal degradability for PP as starch content increases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Ageing studies of pineapple leaf fiber–reinforced polyester composites

This experimental study evaluated the water absorption characteristics of pineapple leaf fiber (PALF)–polyester composites of different fiber content. The degree of water absorption was found to increase with fiber loading. The mechanism of diffusion was analyzed and the effect of fiber loading on the sorption kinetics was studied. The diffusion coefficient was calculated and found to increase with fiber content. Studies were also made to correlate water absorption with the cross‐sectional areas of the specimens. The effects of ageing on the tensile properties and dimensional stability of PALF polyester composites were studied under two different ageing conditions. Ageing studies showed a decrease in tensile strength of the composites. The composite specimens subjected to thermal ageing showed only a slight deterioration in strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 503–510, 2004     

Mechanical properties and water absorption of fiber‐reinforced polypropylene composites prepared by bagasse and beech fiber

The present study investigates the tensile, flexural, notched Izod impact, and water absorption properties of bagasse and beech reinforced polypropylene (PP) composites as a function of fiber content. The surface of fibers was modified through the use of maleated polypropylene (MAPP) coupling agent. From this study, it was found that mechanical properties increase with an increase in fiber loading in both cases. However, the addition of wood fibers resulted in a decrease in impact strength of the composites. The water absorption property at varying fiber loading was evaluated and found maximum for the BA/PP composites. The weight gains for all specimens were less than 7%. In general, the results showed the usefulness of bagasse fiber as a good alternative and reinforcing agent for composite. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of filler content and size on the properties of ethylene vinyl acetate copolymer–wood fiber composites

In this study, the main focus was on the effect of wood fiber (WF) content and particle size on the morphology and mechanical, thermal, and water‐absorption properties of uncompatibilized and ethylene glycidyl methacrylate copolymer (EGMA) compatibilized ethylene vinyl acetate copolymer–WF composites. For uncompatibilized composites, the tensile strength decreased with increasing WF content, whereas for compatibilized composites, the tensile strength initially decreased, but it increased for composites containing more than 5% WF. Small‐WF‐particle‐containing composites had higher tensile strengths than composites containing larger WF particles, both in the presence and absence of EGMA. WF particle size did not seem to have much influence on the degradation behavior of the composites, whereas water absorption by the composites seemed to be higher in composites with smaller particle sizes for both compatibilized and uncompatibilized composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3645–3654, 2007     

氧化石墨烯增强环氧树脂复合材料的制备与性能

利用二乙烯三胺在氧化石墨烯(GO)表面引入氨基基团得到改性GO,然后与环氧树脂(EP)复合,制备出GO增强EP复合材料。性能测试结果表明,该复合材料具有良好的疏水性及力学性能。复合材料的吸水率随着改性GO含量增加先降低后提高,当改性GO含量为0.2%时,吸水率最低,浸泡12 d后吸水率为0.125%,与纯EP相比降低了81.48%,当改性GO含量继续增加,由于复合材料界面局部空隙的增加,吸水率反而大幅上升。复合材料的拉伸强度、冲击强度随着改性GO含量增加先提高后降低,当改性GO含量为0.05%时,拉伸强度、冲击强度最高,分别为50.94 MPa,5.78 k J/m2,相比纯EP增加了104%和90%。综合考虑,当改性GO含量为0.05%时,复合材料的分散性能、疏水性及力学性能较优。     

PLA/稻壳粉复合材料界面改性方法及性能研究

以聚乳酸（PLA）和稻壳粉为原料,添加不同含量壳聚糖、硅烷偶联剂和氢氧化钠（NaOH）作为改性剂,通过压膜成型法制备了PLA/稻壳粉复合材料,并对复合材料的力学性能和吸水性进行了测试表征,同时对复合材料进行了X射线衍射仪（XRD）分析。结果表明,当壳聚糖含量为4 g时,复合材料的洛氏硬度较高,其冲击强度、弯曲强度、拉伸强度分别提高了21 %、70 %和47 %, 24 h吸水率降低13 %;当硅烷偶联剂含量为2 g时,其冲击强度、弯曲强度、拉伸强度分别提高50 %、53 %和65 %,24 h吸水率降低43 %;当用6 g NaOH处理时,复合材料的力学性能没有明显改善,24 h吸水率提升57 %;硅烷偶联剂对复合材料具有较好的综合改性效果, 壳聚糖可以较好地改善复合材料的力学性能,NaOH是较为优秀的亲水性改性剂。