木粉增强聚丙烯力学性能的改善方法

以废弃木粉为增强材料,制备了木粉增强聚丙烯复合材料,研究了改善废弃木粉增强聚丙烯复合材料力学性能的途径。结果表明,通过适当的处理方法对木粉进行表面处理、对基体树脂进行改性,可以有效地提高复合体系的界面粘接强度,能大幅度改善复合体系的力学性能;采用短切玻璃纤维及玻璃纤维毡与废弃木粉组合,可以获得力学性能很高、能作为结构材料使用的复合材料。     

硅灰石与连续玻璃纤维毡组合增强聚丙烯的力学性能

采用硅灰石与连续玻璃纤维毡组合增强聚丙烯,研究了硅灰石的含量,玻璃纤维毡的面密度、基体树脂的性质及界面改性等对材料力学性能的影响。结果表明：采用硅灰石与连续玻璃纤维毡组合增强,可提高复合材料的拉伸、弯曲强度及模量,但过高的硅灰石含量,会导致拉伸及弯曲强度下降,材料的力学性能随着所用玻璃纤维毡面密度的增大而显著提高,采用偶联剂对硅灰石进行处理及在基体聚丙烯中添加功能化聚丙烯,可改善界面结合、提高材料性能,随着功能化聚丙烯含量的增加,材料的拉伸、弯曲强度及模量有所提高,但含量过高时,会引起材料冲击强度的下降;组合增强材料的性能与基体树脂本身的力学性能密切相关,同时还受基体树脂熔体流动性的影响。     

木粉增强HDPE复合材料的制备及其性能研究

以废弃木粉为增强材料,采用双螺杆挤出机,制备木粉增强高密度聚乙烯复合材料,研究改善木粉增强高密度聚乙烯复合材料力学性能的途径。结果表明,随着木粉加入量的增加复合体系的力学性能得到明显改善;通过适当的方法对木粉进行表面处理、对基体树脂进行改性,可以有效地提高复合体系的界面粘接强度,大幅度改善复合体系的力学性能;采用短切玻璃纤维与木粉组合,可以获得力学性能很高,能作为结构材料使用的复合材料。     

玻璃纤维增强聚丙烯复合材料的研究进展

综述了长、短玻璃纤维增强聚丙烯（GFRPP）复合材料的研究进展，总结出纤维含量、纤维长度及分布、纤维取向及分布、纤维与基体界面结合和改性等均为影响GFRPP性能的因素。在复合材料中，长度大于临界长度的玻璃纤维对材料的强度才有作用；增强玻璃纤维与聚丙烯的界面结合也是提高增强效果的有效手段。     

木粉/聚丙烯复合材料力学性能及结晶行为研究

研究了木粉/聚丙烯复合材料的力学性能,结晶行为和微观结构.在木粉含量很高的情况下材料保持很好的拉伸强度,而材料的韧性随着木粉含量的增加下降很大.增容剂MA-PP的加入对材料的拉伸强度很很大的提高,而对冲击强度的影响不大.木粉/PP复合材料的结晶温度随着木粉含量的增加而增大,表明木粉对PP有异相成核的作用.复合材料电镜照片显示木粉在树脂中即使在较高含量下也分散均匀,马来酸改性聚丙烯(MA-PP)的加入提高木粉与树脂基体的界面结合.     

粉末浸渍长玻璃纤维增强聚丙烯的注塑

采用粉末浸渍的方法制备连续玻璃纤维增强聚丙烯预浸料,经切割获得长纤维增强聚丙烯粒子,探索了材料的注塑工艺,研究了注塑后材料的力学性能及其影响因素。结果表明,粉末浸渍的长纤维增强聚丙烯经注塑后可获得力学性能的制品;随着预浸料切割长度的增长、纤维含量的增加,材料的力学性能提高;在基体聚丙烯中添加接枝极性基团的功能化聚丙烯,可改善体系的界面结合,提高材料的力学性能,但功能化聚丙烯的含量超过一定值后,材料的冲击强度有所下降;控制注塑时的模具温度,可以改变材料的一些力学性能。     

界面改性方法对玻纤增强聚丙烯复合材料力学性能的影响

在对玻璃纤维的偶联剂处理,基体接枝改性的基础上,考察不同界面改性方法对玻纤增强聚丙烯力学性能的影响,并通过扫描电镜对玻纤增强聚丙烯的界面进行研究。结果表明,经偶联剂表面处理的玻纤与未经接枝改性的聚丙烯不能形成有效的界面粘结,力学性能较差,而与接枝改性的聚丙烯界面粘结较好,力学性能也有较大幅度的提高;经偶联剂处理的玻纤能与改性聚丙烯形成良好的界面粘结,改善复合材料的力学性能,偶联剂种类的变化在一定程度上能够改善复合材料的性能。     

长玻璃纤维增强聚丙烯复合材料的高性能、低成本化技术

本文通过直接挤出混炼的方法制备了长玻璃纤维增强聚丙烯复合材料,研究了长纤维增强聚丙烯复合材料高性能、低成本化的方法。通过与连续玻璃纤维增强聚丙烯织物的组合,获得了力学性能超过玻璃纤维毡增强聚丙烯复合材料的高性能复合材料。在树脂基体中掺混廉价的填料及回收的聚丙烯树脂,结合适当的填料表面处理方法及废弃回收树脂的增韧及抗老化改性,在力学性能保持一定水平的基础上,可有效降低材料的成本。     

用废木粉增强聚乙烯的研究

本研究采用废木粉为填料增强改性高密度聚乙烯。评价了马来酸酐接枝高密度聚乙烯（MAH-g-HDPE）对聚乙烯基木塑复合材料的增客效果，研究了木粉含量对复合材料力学性能和其它性能的影响，详细阐述了木粉的增强作用机理。研究结果表明：MAH-g-HDPE可显著增进憎水性基质和亲水性木粉之间的界面相互作用，明显改进复合材料的力学性能；在使用适当相客剂的情况下，木粉可明显提高聚乙烯的拉伸强度、弯曲强度和弯曲模量，具有良好的增强效果；当木粉含量为60％时，复合材料的拉伸强度、弯曲强度、弯曲模量分别高达38MPa、54MPa和3500MPa，若与纯基质相比，分别提高了43．4％、176％和283％。这些实验结果表明，木粉对聚乙烯具有明显的增强效果。     

短玻纤和连续玻纤增强聚丙烯复合材料的性能比较研究

文分别研究了短玻纤和连续玻纤增强聚丙烯复合材料的性能,讨论了增容剂即马来酸酐接枝聚丙烯(PP-g-MAH)含量、玻纤含量、挤出工艺、玻纤长度等因素对玻纤增强聚丙烯性能的影响。结果表明,PP-g-MAH的加入增强了界面粘接强度,显著提高玻纤增强聚丙烯复合材料的力学性能;适当提高挤出温度和降低螺杆转速可提高玻璃纤维增强聚丙烯复合材料的力学性能;连续玻纤增强聚丙烯复合材料的力学性能大大优于短玻纤增强聚丙烯复合材料的力学性能。     

Mechanical properties of injection molded long fiber polypropylene composites,Part 1: Tensile and flexural properties

Innovative polymers and composites are broadening the range of applications and commercial production of thermoplastics. Long fiber‐reinforced thermoplastics have received much attention due to their processability by conventional technologies. This study describes the development of long fiber reinforced polypropylene (LFPP) composites and the effect of fiber length and compatibilizer content on their mechanical properties. LFPP pellets of different sizes were prepared by extrusion process using a specially designed radial impregnation die and these pellets were injection molded to develop LFPP composites. Maleic‐anhydride grafted polypropylene (MA‐g‐PP) was chosen as a compatibilizer and its content was optimized by determining the interfacial properties through fiber pullout test. Critical fiber length was calculated using interfacial shear strength. Fiber length distributions were analyzed using profile projector and image analyzer software system. Fiber aspect ratio of more than 100 was achieved after injection molding. The results of the tensile and flexural properties of injection molded long glass fiber reinforced polypropylene with a glass fiber volume fraction of 0.18 are presented. It was found that the differences in pellet sizes improve the mechanical properties by 3–8%. Efforts are made to theoretically predict the tensile strength and modulus using the Kelly‐Tyson and Halpin‐Tsai model, respectively. POLYM. COMPOS., 28:259–266, 2007. © 2007 Society of Plastic Engineers     

Polypropylene–glass fiber/basalt fiber hybrid composites fabricated by direct fiber feeding injection molding process

Hybrid composites of polypropylene reinforced with glass fibers and basalt fibers were fabricated by vented injection molding machine which is named the direct fiber feeding injection molding (DFFIM) process. Polyamide 6 and maleic anhydride‐grafted polypropylene has been used as a coupling agent to improve the interfacial bonding between the fibers and matrix. Two types of vented injection molding machines with a different check ring and mold were used for making specimens. The fiber lengths were analyzed to identify the most suitable check ring and mold for the DFFIM process. The mechanical properties of the hybrid composites were investigated by tensile, flexural and Izod impact tests. The interfacial morphology of the fractured tensile specimens was studied by using scanning electron microscopy and showed that there is a fiber agglomeration phenomenon that occurs in the hybrid composites, and it has a significant effect on the mechanical properties of hybrid composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45472.     

Effect of macromolecular coupling agent on the property of PP/GF composites

Silane‐grafted polypropylene manufactured by a reactive grafting process was used as the coupling agent in polypropylene/glass‐fiber composites to improve the interaction of the interfacial regions. Polypropylene reinforced with 30% by weight of short glass fibers was injection‐molded and the mechanical behaviors were investigated. The results indicate that the mechanical properties (tensile strength, tensile modulus, flexural strength, flexural modulus, and Izod impact strength) of the composite increased remarkably as compared with the noncoupled glass fiber/polypropylene. SEM of the fracture surfaces of the coupled composites shows a good adhesion at the fiber/matrix interface: The fibers are coated with matrix polymer, and a matrix transition region exists near the fibers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1537–1542, 1999     

长玻纤增强聚丙烯复合材料力学性能的研究进展

综述了长玻纤增强聚丙烯复合材料(LGFPP)力学性能的研究进展,包括玻纤含量、玻纤和聚丙烯树脂基体间的界面结合状态以及加工工艺等因素对LGFPP力学性能的影响,并对LGFPP的研究趋势进行了展望。     

短玻纤增强聚丙烯的研究进展

综述了近年来有关短玻纤增强聚丙烯复合材料的力学性能、变形机理和断裂韧性等方面的研究工作。短玻纤取向后的复合材料注射样的力学性能是各向异性的 ,复合材料在取向方向上具有更高的拉伸强度。玻纤与树脂基体间界面结合力的强弱对材料的力学性能同样起着至关重要的作用。良好的界面结合力保证了应力有效地从基体向玻纤传递 ,从而提高了复合材料的强度。由于短玻纤的分布既不均匀又不规则 ,在受到负荷时的变形过程很复杂 ,包括玻纤 -基体的界面脱黏、脱黏后的摩擦、基体的塑性变形、玻纤的塑性变形、玻纤断裂、基体断裂和玻纤抽出等     

分流板对长纤维增强聚丙烯挤出过程中纤维断裂和分散的影响

采用自主研发的在线混合生产设备制备了长玻璃纤维增强聚丙烯复合材料。研究了分流板在挤出加工过程中对纤维断裂和分散的影响,测定了复合材料的力学性能。结果表明,分流板的加入会使纤维断裂加剧并且有利于纤维束进一步分散,但是随着纤维含量的增加,这种影响变得不明显。当纤维含量为10%时,分流板的加入不利于复合材料性能的提高,而当纤维含量为20%时,复合材料的性能明显改善。     

Effect of impregnation time on performance of long glass fiber‐reinforced polypropylene composites

Long glass fiber (LGF)‐reinforced polypropylene (PP) composites were prepared using self‐designed impregnation device. Effects of impregnation time on mechanical properties, crystallization, dynamic mechanical properties, and morphology of PP/LGF composites were investigated. The experiment results demonstrate that the excellent tensile strength, Notched Izod impact strength was 152.9 MPa, 31.2 KJ/m², respectively, and the stiffness of PP/LGF composites was higher, when the impregnation time was 7.03 s. The excellent interfacial adhesion between PP and glass fiber indicates that PP/LGF composites possess the outstanding mechanical properties. The impregnation time scarcely influenced thermal properties of PP/LGF composites. J. VINYL ADDIT. TECHNOL., 24:174–178, 2018. © 2016 Society of Plastics Engineers     

玻璃纤维增强聚丙烯复合材料耐水解性能的研究

以玻璃纤维增强聚丙烯复合材料为研究对象,选取两种玻璃纤维、不同相容剂及不同含量探讨玻璃纤维增强聚丙烯复合材料的性能,研究了在95℃水煮24 h前后的力学性能、微观结构和结晶变化。结果表明,添加聚丙烯专用耐水解玻璃纤维,在相容剂含量为3%时,可以大大提高聚丙烯材料的力学性能和耐水解性能,已经被应用于洗衣机滚筒等长期水接触的部件。     

INFLUENCE OF COMPATIBILIZATION TREATMENTS ON THE MECHANICAL PROPERTIES OF FIQUE FIBER REINFORCED POLYPROPYLENE COMPOSITES

Fique fibers reinforced polypropylene (PP) composites have been investigated for different fiber lengths and contents. Fiber/matrix interfacial adhesion has been modified by fiber treatments such as mercerization, esterification with maleic anhydride, and adding of an isocyanate compound. A copolymer of polypropylene with maleic anhydride has been employed as compatibilizer agent, by previous mixing with PP matrix. Both compatibilization ways improve fiber/matrix adhesion, as shown by changes of the free surface energy of fibers and also by SEM analysis. Addition of the compatibilizer agent leads to higher flexural properties than those obtained for composites where the fibers were treated. Dynamical mechanical properties of composites seem to indicate that movement in the crystalline PP phase, possibly occurring on the fiber/matrix interphase, takes place in between the glass transition and the melting temperatures of PP matrix.     

PP-g-MAH预浸渍玻璃纤维毡对GMT界面改性的作用

采用含有马来酸酐接枝聚丙烯(PP–g–MAH,简称MPP)的聚丙烯(PP)树脂对玻璃纤维(GF)毡预浸渍,进行增强体改性,通过直接浸渍工艺、增强体预浸渍工艺、累加浸渍工艺等不同工艺制备GF毡增强PP热塑性复合材料(GMT)。对不同工艺制备的GMT界面形态进行了扫描电子显微镜分析,并测定了预浸渍处理后GF的疏水性,研究了预浸渍工艺中MPP的用量对GMT拉伸、弯曲、冲击等力学性能的影响。结果表明:采用含MPP的PP树脂进行增强体预浸渍改性的方法,改性树脂对GF的包覆效果良好,经预浸渍改性法处理的GF,其疏水性增强;并可以获得与PP/MPP改性树脂直接浸渍GF毡时相似的界面改性效果和相近的GMT力学性能;样品界面改性效果相近的情况下,增强体预浸渍改性方法所需的MPP用量明显少于改性树脂直接浸渍时的用量。