PTW增强POM/TPU复合材料的制备及性能研究

以钛酸钾晶须(PTW)为增强体,采用熔融共混和注射成型法,制备了聚甲醛(POM)/热塑性聚氨酯弹性体(TPU)/PTW复合材料。研究了PTW含量对POM/TPU复合材料力学性能的影响,并借助扫描电子显微镜(SEM)分析了冲击断面形貌。结果表明,TPU的加入有效改善了纯POM的韧性,当TPU含量为10%(质量分数,下同)时,缺口冲击强度是纯POM的2.5倍,但拉伸强度和弯曲强度有所下降;PTW的加入对POM/TPU有较好的增强效果,当PTW含量为15%时,复合材料的拉伸强度、拉伸模量、断裂伸长率、弯曲强度、弯曲模量、缺口冲击强度分别为35.91 MPa、24.17%、144.94MPa、12.26GPa、112.1kJ/m2,拉伸模量、弯曲模量、缺口冲击强度与POM/TPU相比分别提高了14.7%、54.2%和9.2%,综合力学性能达到最佳。     

HDPE/SFCM复合材料的性能研究

以高密度聚乙烯(HDPE)为基体,剑麻纤维素微晶(SFCM)为改性剂,采用熔融法制备HDPE/SFCM复合材料,研究了SFCM的用量对HDPE/SFCM复合材料的力学性能、热性能、熔体流动性、熔融结晶行为和断面形貌的影响。结果表明,SFCM的加入可明显提高HDPE/SFCM复合材料的拉伸模量、弯曲强度及弯曲模量,但对材料的拉伸强度影响不明显,且降低了材料的冲击韧性。同时,SFCM的加入可小幅提高复合材料的维卡软化点,降低材料的熔体流动速率,对材料的熔融温度及结晶温度影响不大,但可提高HDPE的结晶度。当加入12份的SFCM时,HDPE/SFCM复合材料的拉伸模量、弯曲强度及弯曲模量比HDPE的分别提高了138.1%,21.1%,33.3%,其结晶度比基体HDPE提高了20.5%。     

母粒法制备聚丙烯/炭化纤维素纳米晶复合材料

将冷冻干燥的纤维素纳米晶(CNC)进行高温处理,制成炭化纤维素纳米晶(CCNC),采用超声母料法将CCNC以母料的形式与聚丙烯(PP)制成PP/CCNC复合材料。使用SEM观察了CNC炭化前后的形貌变化情况以及CCNC在复合材料的分散情况;通过拉伸性能测试考察了CCNC对复合材料力学性能的影响;采用DMA测试了CCNC对复合材料黏弹性的影响。SEM结果表明:CNC经过冷冻干燥、高温炭化后,由纳米棒状结构变成有序带状结构;复合材料的断面表明CCNC可以以纳米片的形式分散在PP基体中。拉伸测试结果表明:CCNC的加入使复合材料的拉伸强度和断裂伸长率下降,模量上升。强度下降表明CCNC与基体的界面相容性有待进一步提高。DMA测试结果发现:CCNC可明显增加复合材料的储能模量,30%的CCNC即可使模量提高135.7%;复合材料的损耗模量随着CCNC的加入呈现上升趋势。     

短玻纤增强聚丙烯复合材料性能研究

研究了玻璃纤维(GF)、自制马来酸酐接枝聚丙烯(PP-g-MAH)和螺杆转速对短玻纤增强聚丙烯(PP/SFT)复合材料力学性能和微观形貌的影响。结果表明:随着GF用量增加,复合材料的弯曲模量和缺口冲击强度增大,拉伸强度先增大后降低,PP/SFT复合材料断面呈现脆性断裂;随着增容剂PP-g-MAH用量增加,拉伸强度和缺口冲击强度先增加后降低,弯曲模量基本不变;当PP,GF和PPg-MAH的质量比为50∶50∶3时,其综合性能最优,拉伸强度为113.0 MPa,冲击强度为15.8kJ/m~2,复合材料断面呈现韧性断裂;螺杆转速和剪切增大会降低纤维平均长度和复合材料的力学性能。     

PBO增容PBAT/淀粉复合材料的制备

以2,2-(1,3-亚苯基)-二噁唑啉（PBO）为增容剂，二羟甲基丙酸为活性组分，制备了聚己二酸对苯二甲酸丁二酯（PBAT）/淀粉复合材料，采用热重分析仪、电子万能材料试验机、扫描电子显微镜分析了材料的热性能、力学性能及断面形貌。结果表明：随PBO用量的增加，复合材料的热稳定性、拉伸强度、拉伸模量、断裂拉伸应变出现了先上升后下降的趋势；PBO的加入使淀粉、PBAT的熔点下降，结晶温度上升；当PBO质量分数为1.0%时，复合材料的相容性、热稳定性最好，拉伸强度、拉伸模量、断裂拉伸应变最大，分别为5.91 MPa,68.3 MPa,320%。     

偶联剂Si69对EPDM/MF复合粘接剂粘接性能的影响

以三元乙丙橡胶(EPDM)为基体,添加适量的三聚氰胺甲醛树脂(MF)和三聚氰胺,制备了橡胶基复合粘接剂。以偶联剂Si69为增容剂,改善基体与三聚氰胺甲醛树脂的相容性。考查了MF树脂/三聚氰胺用量和偶联剂Si69用量对复合材料力学性能和粘接性能的影响,优化了硫化工艺参数。研究结果表明:随着MF树脂/三聚氰胺用量的增加,复合材料的力学性能和粘接性能变差;随着偶联剂Si69用量的增加,材料的拉伸强度和粘接强度先增大后减小,断裂伸长率增加;偶联剂Si69可以明显改善材料的力学性能和粘接性能;m(MF树脂)∶m(三聚氰胺)为20:40或30:30,偶联剂Si69用量在6～9份时,复合材料的拉伸强度和粘接强度优异。     

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。     

热压烧结莫来石纤维增强羟基磷灰石性能研究

通过水热合成法制备了均匀分散的莫来石纤维(MF)-羟基磷灰石(HA)复合粉体,进而利用热压烧结制备了MF增强HA复合材料(MF/HA)。研究了MF的添加及不同烧结工艺对复合材料微观形貌,组织结构及生物、力学性能的影响。结果表明:在高温烧结过程中,MF的添加使得复合材料中有了新相的产生并出现了微晶化现象。当烧结时间为120 min时,在1250℃下烧结的MF/HA复合材料压缩强度和压缩模量分别达到131.04±3.25 MPa和0.350±0.023 GPa。体外模拟体液实验表明,MF/HA复合材料具有良好的生物活性。     

HTPB基PBX的模量与撞击感度的关系

为改善HTPB基PBX炸药的易损性,研究了炸药的模量与撞击感度之间的关系。通过改变端羟基聚丁二烯（HTPB）基PBX的固化参数与黏结剂的含量,制备了一系列具有不同模量的PBX,利用50％特性落高法对其撞击感度进行测试。结果表明,PBX的撞击感度随抗张模量和压缩模量的下降而降低。从理论上分析了影响撞击感度的模量因素和机理,认为通过调整PBX的力学性能可改善PBX炸药的机械撞击感度。     

MDI增容茶粉/聚乳酸生物质复合材料的制备与性能

以茶废弃物(TW)为填料、聚乳酸(PLA)为基体,二苯基甲烷二异氰酸酯(MDI)为偶联剂,经密炼-注塑工艺制备了TW/PLA复合材料,考察了MDI对该复合材料结构与性能的影响。结果表明,MDI的添加改善了TW与PLA的界面相容性,提高了TW/PLA复合材料的力学性能、储能模量、玻璃化转变温度及热稳定性,降低了复合材料吸水率。在MDI添加量为TW用量的2%时,复合材料的力学性能最佳,与未增容TW/PLA复合材料相比,其拉伸强度、弯曲强度及缺口冲击强度分别提高18.9%、17.6%和7.2%,拉伸模量和弯曲模量分别提高12.6%和30.6%。     

Enhanced thermal and mechanical properties of PW‐based HTPB binder using polystyrene (PS) and PS–SiO2 microencapsulated paraffin wax (MePW)

Polystyrene (PS) microencapsulated paraffin wax (MePW) and PS–SiO₂ MePW were used to improve the form‐stability of PW in hydroxyl‐terminated polybutadiene‐derived polyurethane (HTPB) binder. HTPB matrix containing different contents of PS MePW, PS–SiO₂ MePW, and PW were prepared. The chemical composition, crystallinity, microstructure, heat capacities, thermal stabilities, thermal reliabilities, leakage, and mechanical properties of the composites were compared using Fourier transforms infrared spectroscope, X‐ray diffractometer, scanning electronic microscope, differential scanning calorimeter, thermo‐gravimetric analyzer, thermal cycling test, leaking test, compression, and tensile tests, respectively. The results showed that the MePW/PW/HTPB composites were prepared without chemical reaction. The thermal stability and mechanical properties of PS–SiO₂ MePW/PW/HTPB increased more dramatically than that of PS MePW/PW/HTPB. With the increasing contents of MePWs, the PW leakage of the composites decreased, especially for PS MePW/PW/HTPB. Consequently, the MePW/PW/HTPB composites possess a potential application for PW‐based polymer‐bonded explosive system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46222.     

Morphological,mechanical, and physical properties of composites made with wood flour‐reinforced polypropylene/recycled poly(ethylene terephthalate) blends

Wood flour (WF)‐filled composites based on a polypropylene (PP)/recycled polyethylene terephthalate (r‐PET) matrix were prepared using two‐step extrusion. Maleic anhydride grafted polypropylene (MAPP) was added to improve the compatibility between polymer matrices and WF. The effects of filler and MAPP compatibilization on the water absorption, mechanical properties, and morphological features of PP/r‐PET/WF composites were investigated. The addition of MAPP significantly improved mechanical properties such as tensile strength, flexural strength, tensile modulus, and flexural modulus compared with uncompatibilized composites, but decreased elongation at break. Scanning electron microscopic images of fracture surface specimens revealed better interfacial interaction between WF and polymer matrix for MAPP‐compatibilized PP/r‐PET/WF composites. MAPP‐compatibilized PP/r‐PET/WF composites also showed reduced water absorption due to improved interfacial bonding, which limited the amount of absorbable water molecules. These results indicated that MAPP acts as an effective compatibilizer in PP/r‐PET/WF composites. POLYM. COMPOS., 38:1749–1755, 2017. © 2015 Society of Plastics Engineers     

Chemical Modification of Chitosan-Filled Polypropylene (PP) Composites: The Effect of 3-Aminopropyltriethoxysilane on Mechanical and Thermal Properties

Chitosan was used as filler in polypropylene (PP) polymer. In order to improve compatibility between chitosan and PP, chitosan was chemically modified with 3-aminopropyltriethoxysilane (3-APE). The results show that the increasing of filler content decreased tensile strength and elongation at break, but increased Young's modulus of composites. The treated composites exhibit higher tensile strength and Young's modulus, but lower elongation at break compared untreated composites. The addition of 3-APE has improved thermal properties such as thermal stability and crystallinity of treated composites. SEM study of the tensile fracture surface of treated composites shows better interfacial interaction and adhesion between the chitosan-PP matrix.     

Effects of methyl methacrylate grafting and polyamide coating on the interfacial behavior and mechanical properties of jute‐fiber‐reinforced polypropylene composites

In recent years, environmentally friendly materials have become popular because of the growing environmental demands in human society. Natural fibers are now widely used as reinforcements in polymer matrix composites for their various advantages such as low cost, light weight, abundant resources, and biodegradability. However, the applications of these kinds of composites are limited because of their unsatisfactory mechanical properties, which are caused by the poor interfacial compatibility between the fibers and the thermoplastic matrix. In this paper, three methods, including (i) alkali treatment, (ii) alkali and methyl methacrylate (MMA) treatment, and (iii) alkali and polyamide (PA) treatment (APT), were used to treat jute fibers and improve the interfacial adhesion of jute‐fiber‐reinforced polypropylene (PP) composites (JPCs). The mechanical properties of the JPCs were tested, and their impact fracture surfaces were observed. Infrared spectral analysis showed that MMA was grafted and that PA was coated onto the surface of jute fibers. Mechanical tests indicated that the three kinds of pretreated composites presented better mechanical properties than untreated composites. Among them, the APT composite had the best comprehensive properties. Compared with untreated composites, the tensile strength, flexural strength, and flexural modulus of APT composite were increased by 24.8, 31.3, and 28.4%, respectively. Analysis by scanning electron microscopy showed that better interfacial compatibility between jute fibers and PP occured in this kind of composite. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers     

回收聚丙烯/废书刊纸纤维复合材料结构与力学性能的研究

以废书刊纸纤维(OMGF)和回收聚丙烯(PP)为原料,马来酸酐接枝聚丙烯(MAPP)为相容剂,采用热压成型法制备了PP/OMGF木塑复合材料。研究了OMGF含量对复合材料拉伸性能及弯曲性能的影响,并采用红外光谱和扫描电子显微镜分析了OMGF的结构及复合材料的拉伸断面形貌。结果表明,OMGF对PP基体具有一定的增强作用,当OMGF含量为30%时,复合材料的拉伸强度和弯曲强度分别达到最大值29.53MPa和33.67MPa,比回收PP分别提高了51.6%和31.7%;随着OMGF含量的增加,复合材料的断裂伸长率逐渐下降,弯曲模量逐渐上升。扫描电子显微镜分析显示,当OMGF含量较低时,其与PP基体之间具有良好的界面相容性;当OMGF含量增加到50%时,界面相容性明显下降。     

HDPE/功能化石墨烯复合材料制备及性能研究

氧化石墨烯(GO)具有较高的比表面积,层间距大,表面拥有丰富的官能团,可以很好地分散到聚合物中,但GO导电性差。研究对GO进行还原和表面修饰,以改善石墨烯和HDPE的相容性。采用熔融混炼法制备了HDPE/石墨烯复合材料,结合力学性能、导电性能、微观结构测试,考察不同HDPE/石墨烯复合材料的导电阈值,分析影响复合材料导电性的因素,进而得出较优化的制备工艺。研究发现石墨烯添加量为7.5%时,导电通路开始形成,当石墨烯含量达到7.5%时,拉伸强度提升22.14%,拉伸模量提升21.19%。     

Performance of hybrid reinforcements in PVC composites. II: Use of surface-modified mica and different cellulosic materials as reinforcements

The effect of the composition of various wood fibers and surface-treated mica as well as different surface treatments of cellulosic materials on the mechanical properties of PVC composites has been evaluated. Cellulosics were surface modified by prior coating with maleic andydride (MA), mixtures of MA and Na-silicate and isocyanate. The filler concentration was fixed at 25 wt%. Both tensile strength and modulus of composities filled solely with mica are superior to those of non-treated wood fiber-filled composities. while the reverse is true for impact strength (except for bagasse-filled composities), ultimate elongation, and tensile toughness. Moreover, the mechanical properties of composities, with the exception of modulus, filled only with mica and/or non-treated wood fibers are inferior to those of unfilled PVC. Compared to non-treated fiber-filled composites, properties improved when surface-modified wood fibers were used alone, or along with mica. Isocyanate-coated wood fibers ranked best with regard to the mechanical properties of the composities. Properties also changed with the change of wood species and compositions of mica and wood fibers. Experimental results indicate good compatibility between surface-treated wood fibers/mica and PVC composities.     

Thermal,mechanical, and morphological investigation of injection molded poly(trimethylene terephthalate)/carbon fiber composites

Injection molded poly(trimethylene terephthalate) (PTT)/carbon fiber (CF) composites have been fabricated using a twin screw micro compounder. The effect of CF reinforcement on the thermal, mechanical, dynamic mechanical, and microscopic properties of the composite was investigated. Addition of 30 wt% of CF into PTT resulted in the significant enhancement of tensile (120%) and flexural (30%) strength compared to neat PTT. The rule of mixture was successfully employed for theoretical calculations of tensile modulus and the calculated values were compared with the experimental results. Similarly, CF reinforced (30 wt%) PTT composites exhibited an increase of more than a 150°C in the heat deflection temperature. Scanning electron microscopy analysis of the tensile fracture specimens revealed uniform distribution of the CFs with good polymer matrix and fiber adhesion. Overall, the results obtained indicate the enhancement of properties with increasing fiber content, confirming better fiber and polymer matrix compatibility. POLYM. COMPOS., 33:1933–1940, 2012. © 2012 Society of Plastics Engineers     

剑麻纤维/聚丙烯木塑复合材料的热氧老化性能研究

以剑麻纤维(SF)、聚丙烯(PP)为原料,经熔融共混、模压成型工艺制备木塑复合材料。探讨了SF/PP复合材料的力学性能、热性能随老化时间和SF含量的变化规律,借助扫描电镜对复合材料老化前后的冲击断面进行微观结构分析。结果表明:老化后复合材料的冲击强度、弯曲强度和弯曲模量随剑麻含量的增加而降低;同时,复合材料中PP相的结晶速率、结晶度也有所降低,但复合材料的热稳定性基本没有变化。