印刷包装废纸在复合材料领域的回用技术新进展

介绍了国内外印刷包装废纸的分类及其回用现状,综述了印刷包装废纸在废纸/热塑性聚合物复合材料、废纸发泡材料、废纸纤维/可生物降解复合材料及其他废纸复合材料等领域的再利用技术新进展,分析了印刷包装废纸在材料领域回收再利用技术的发展趋势,提出应进一步探讨不同种类印刷包装废纸对复合材料性能及废纸纤维/树脂界面相容性的影响等研究方向.     

废纸浆增强玉米淀粉基复合材料的制备及其力学性能研究

以甘油和尿素作为混合塑化剂、废纸浆为增强体,玉米淀粉、聚乙烯醇为基体,利用熔融共混法制备了废纸浆增强玉米淀粉复合材料。研究了混合增塑剂、废纸浆、水含量、氢氧化钠浓度对复合材料力学性能的影响。力学性能测试结果表明,甘油和尿素混合塑化剂对复合材料有反增塑作用,当甘油/尿素含量分别为10/20份时,拉伸强度最佳为10.26MPa;氢氧化钠浓度为4%时,复合材料综合力学性能最好;废纸浆对复合材料有增强作用,当含量为35份时,拉伸强度最佳为11.35MPa;随着含水率的增加,材料的拉伸强度降低,断裂伸长率先增加后降低;扫描电镜观察发现,甘油和尿素混合塑化剂能够增塑淀粉,很好的改善废纸浆和玉米淀粉之间的相容性。     

新型石墨烯复合材料的研究进展

石墨烯复合材料具有不同的结构和组成,包括石墨烯/聚合物、石墨烯/金属、石墨烯/金属氧化物等二元复合材料以及石墨烯/无机材料/聚合物三元复合材料.它们优异的物理和化学性质,在众多领域内显示出广阔的应用前景,如储能、传感器、催化剂载体和电极材料等领域.制备具有新颖结构和组成的石墨烯材料及其应用研究已经成为复合材料领域的研究前沿和热点之一.综述了新型石墨烯复合材料的制备、组成以及应用的研究进展,探讨了该研究领域亟待解决的问题以及今后可能的发展前景.     

新型基片材料——C/SiC复合材料

阐述了目前常用的3大类基片材料,即塑料基、金属基和陶瓷基材料,比较了3类材料的性能,得出了陶瓷基材料是综合性能较好的基片材料的结论,并比较了目前陶瓷基片材料中的Al2O3、AlN、BeO、SiC的性能,认为SiC作为基片材料具有良好的发展前景;针对单相SiC陶瓷固有脆性导致难以大尺寸成型的问题,提出了使用C/SiC复合材料制备基片材料的可能性,并综述了C/SiC复合材料的制备工艺,比较了3种工艺(PIP、CVI、LSI)所制备的材料的性能,认为液相渗硅(LSI)C/SiC复合材料制备大尺寸封装基片材料是未来最具前景的发展方向。     

废纸纤维/微晶纤维素增强PHBV复合材料性能研究

以聚羟基丁酸戊酸共聚酯(PHBV)作为基体,微晶纤维素(MCC)和废纸纤维作为增强体,采用注塑成型的方法制备可生物降解的复合材料。研究不同质量分数的MCC以及不同质量分数的废纸纤维作为共混填充材料对复合材料的力学、吸水及界面性能的影响。结果表明添加MCC后的复合材料力学性能整体都得到了提高,且在MCC质量分数为3%时复合材料的综合力学性能最好,共混填充后的复合材料则在废纸纤维的质量分数为10%时综合力学性能最好;复合材料的吸水性随着废纸纤维含量的增加而上升。扫描电镜分析发现,MCC与PHBV界面相容性较好,共混废纸纤维后界面性能下降。     

淀粉-纤维复合发泡缓冲材料的研究

为制备可降解缓冲包装材料,将淀粉与废纸纤维材料混合,通过控制材料的含水量及添加剂含量,使定量材料在一定温度和压力下模压发泡成型。结果表明,在模压温度为170℃,合模压力为23 kPa,保压时间为5 min的加工条件下,纤维量的增加使材料密度、载荷能力得到了升高,并提高了复合材料高应力条件下的缓冲性能。     

偶联剂改性废纸/PETG生物复合材料

目的制备可生物降解的偶联剂改性废纸/PETG木塑复合材料,并检测其各方面的性能。方法分别采用偶联剂KH550,KH560和KH570对废纸粉进行改性处理,并与PETG制备木塑生物复合材料,通过傅里叶变换红外光谱、力学性能检测、吸水性能分析、扫描电镜和热重分析,研究偶联剂的加入对材料结构、力学性能、吸水性、微观形貌和热稳定性的影响。结果 KH550对复合材料性能的增强效果最好,当KH550质量分数为1%时,复合材料的拉伸强度和弯曲强度达到峰值,分别提高了32.8%和13.7%。结论偶联剂能明显改善复合材料的力学性能和热稳定性,降低其吸水率,在包装领域具有很好的应用前景。     

热致性液晶/氧化石墨烯/酚醛树脂复合材料的力学性能与摩擦性能研究

将酰氯化后的氧化石墨烯与热致性液晶聚合物经溶液混合法制备热致性液晶聚合物/氧化石墨烯(TLCP/GO)混杂材料;通过辊炼、挤出、模压成型工艺制备热致性液晶聚合物/氧化石墨烯/酚醛树脂(TLCP/GO/PF)复合材料,研究TLCP/GO混杂材料含量对酚醛树脂复合材料的力学、动态力学及摩擦性能的影响。结果表明:添加量为0.5%时复合材料的弯曲强度及弯曲模量分别提高了26%及11%;添加量为0.5%时,复合材料初始储能模量提高了31.5%,同时,混杂材料的加入一定程度上改善了复合材料的摩擦磨损性能,其中混杂材料添加量为0.5%时,复合材料的摩擦系数在0.39~0.28之间,250℃时,复合材料的磨损率为0.39×10-7cm3/N·m,比纯酚醛复合材料降低48.7%,表明TLCP与GO具有协同增强作用。     

锂硫二次电池硫正极复合材料的改性研究进展

在能源问题日益严重的今天,硫正极材料探索与研究越来越受到人们的关注。主要从硫/纳米金属氧化物、硫/导电高聚物、硫/碳、硫/碳/导电高聚物4个方面综述了各种硫正极复合材料的优缺点、制备及改性的方法,重点介绍了不同的复合材料对电化学性能的影响,为新型硫正极材料的制备和改性指明了方向。     

SiO2-乙酰胺复合储热相变材料的制备

采用溶胶-凝胶法将有机相变材料乙酰胺嵌入到SiO2网络空间内,制备了复合储热相变材料.通过对比实验,研究了相变材料的种类、相变材料的加入量及催化剂种类对复合材料性能的影响.研究结果表明:采用氨水作催化剂,乙酰胺作相变材料,可制备出储热能力高、疏松多孔的复合材料,复合材料的相变温度为69.1℃,相变潜热高达124.2J/g;且复合材料中包含相变材料的质量分数越高,其储热能力越高.     

纤维束增强复合材料的横向弹塑性性能研究

利用细观力学模型和有限元法研究纤维束复合材料的横向弹塑性力学性能。假设弹性的纤维束均匀地分布于幂硬化弹塑性基体材料中, 并假设纤维束内的纤维接触是光滑的。通过与单丝纤维复合材料的相应结果比较, 研究了纤维成束对复合材料宏观弹塑性性能的影响。通过对硼/铝复合材料的数值研究表明: 纤维的成束对复合材料的横向弹性刚度影响很小, 而对复合材料的塑性变形和切线刚度有显著的影响。      

Calculation of effective coefficients for piezoelectric fiber composites based on a general numerical homogenization technique

Numerical unit cell models for 1–3 periodic composites made of piezoceramic unidirectional cylindrical fibers embedded in a soft non-piezoelectric matrix are developed. The unit cell is used for prediction of the effective coefficients of the periodic transversely isotropic piezoelectric cylindrical fiber composite. Special emphasis is placed on the formulation of the boundary conditions that allows the simulation of all modes of overall deformation arising from any arbitrary combination of mechanical and electrical loading. The numerical approach is based on the finite element method (FEM) and it allows the extension to composites with arbitrary geometrical inclusion configurations, providing a powerful tool for fast calculation of their effective properties. For verification the effective coefficients are evaluated for square and hexagonal arrangements of unidirectional piezoelectric cylindrical fiber composites. The results obtained from the numerical technique are compared with those obtained by means of the analytical asymptotic homogenization method (AHM) for different fiber volume fractions.     

PLA/木质纤维复合材料的制备及性能

目的研究PLA/木质纤维复合材料的制备工艺过程,分析PLA纤维含量对复合材料力学性能的影响,确定最优配比,以获得一种可应用于包装中的新型环保复合材料。方法将不同质量配比的PLA纤维及木质纤维按照造纸的工艺进行抄造,获得湿纸胚后再进行热压处理,获得需要的复合材料。对PLA纤维在复合材料中的分散性以及复合材料的力学性能进行表征与测试。结果分散性试验表明,PLA纤维能够与木质纤维均匀混合;当PLA纤维的质量分数为10%时,复合材料的性能较好。力学测试表明,复合材料的拉伸强度最大可达到42.79 MPa,耐折次数可达到1015次。结论 PLA/木质纤维复合材料可采用造纸的方法进行制备,且力学性能较好,能在包装领域内有较为广泛的应用,同时也为可降解纤维的研究应用提供了一种新思路。     

Mechanical properties of palmyra/glass fiber hybrid composites

Use of eco friendly composites gains attraction due to its lightweight and moderate strength in the recent years. Palmyra fiber is a natural fiber obtained from Palmyra (Borassus flabellifer) tree. Mechanical properties of randomly mixed short fiber composites are studied and optimum fiber length and wt% are estimated. This paper deals with the properties of (randomly mixed) palmyra fiber, glass fiber hybrid composites. Two types of specimens are prepared, one by mixing the palmyra and glass fiber and the other by sandwiching palmyra fiber between the glass fiber mats. Composite plates are prepared for different palmyra/glass fiber weight ratio. Rooflite resin is used as matrix. Tensile, impact, shear and bending properties are studied. The mechanical properties of the composites are improved due to the addition of glass fiber along with palmyra fiber in the matrix. The glass fiber skin–palmyra fiber core construction exhibits better mechanical properties than dispersed construction. Moisture absorption studies are conducted and the results are presented as a function of square root of time. Addition of glass fiber with palmyra fiber in the matrix decreases the moisture absorption of the composites.     

Effective mechanical properties of “fuzzy fiber” composites

In this paper we investigate the mechanical behavior of carbon fiber composites, where the carbon fibers are coated with radially aligned carbon nanotubes. For this purpose we develop a general micromechanics method for fiber composites, where fibers are coated with radially aligned microfibers (“fuzzy fiber” composites). The mechanical effective properties are computed with a special extension of the composite cylinders method. The in-plane shear modulus is determined using an extended version of the Christensen’s generalized self consistent composite cylinders method. The proposed methodology provides stress and strain concentration tensors. The results of the method are compared with numerical approaches based on the asymptotic expansion homogenization method. The combination of composite cylinders method and Mori–Tanaka method allows us to compute effective properties of composites with multiple types of “fuzzy fibers”. Numerical examples of composites made of epoxy resin, carbon fibers and carbon nanotubes are presented and the impact of the carbon nanotubes length and volume fraction in the overall composite properties is studied.     

国产ZT7H碳纤维表面状态及其复合材料界面性能

目前我国在高性能碳纤维研发生产方面已取得了突破性的进展。本文选用不同批次和牌号的国产ZT7H碳纤维,对其进行去浆和上浆处理,并制备碳纤维增强环氧树脂基复合材料,探究国产H1型上浆剂对ZT7H碳纤维表面形貌和微观界面性能的影响及不同牌号碳纤维复合材料界面性能的差异。研究表明,H1上浆剂增加了碳纤维表面粗糙度和极性组分含量,增强了湿热老化前后复合材料的微观界面力学性能。同时,碳纤维织物的编织方式对其复合材料的静态力学性能和界面性能有很大影响。实验证明,国产ZT7H碳纤维的性能已超过东丽T700碳纤维,但其加工工艺性仍有待提升。      

Preparation and mechanical properties of C/SiC composites with carbon fiber woven preform

C/SiC composites reinforced with multilayer carbon fiber woven preforms were fabricated by isothermal chemical vapor infiltration (ICVI) process. To characterize the mechanical properties of the composites, mechanical testing was carried out under various loading conditions, including tension, bending and shear loads. The results indicated that the composites, with superior intrinsic through-the-thickness properties, exhibited high in-plane mechanical properties. Therefore, the composites developed can well meet the demands of the reusable nose cap, i.e. the easiness of near-net shaping and the capability of withstanding multidirectional mechanical and thermal stresses.     

碳纤维复合材料力学性能研究进展

目的 综述碳纤维复合材料这一热结构材料的力学性能研究进展，推进碳纤维复合材料的研制和应用。方法 采用文献调研法，梳理和汇总国内外有关碳纤维复合材料力学性能的研究内容，对二维复合材料、针刺复合材料及三维编织复合材料3种结构进行性能影响因素分析。结论 影响碳纤维复合材料静态和动态力学性能的因素主要有温度、应变率、密度等，提出应进一步开展碳纤维复合材料在多因素耦合及高温动态性能方面的研究。     

Development and effect of alkali treatment on tensile properties of curaua fiber green composites

This paper describes development and improvement of mechanical properties of a so-called green composite that was fabricated by reinforcing a cornstarch-based biodegradable resin with high-strength natural fibers extracted from a plant named curaua. Two fabrication methods are proposed, in which stretched slivers of curaua fibers are prepared as reinforcement to increase the composite strength. Moreover, highly concentrated alkali treatment was applied to curaua fibers to improve mechanical properties of green composites. Tensile test results showed that alkali-treated fiber composites increased in fracture strain twice to three times more than untreated fiber composites, without a considerable decrease in strength. This result proves that appropriate alkali treatment is a key technology for improving mechanical properties of cellulose-based fiber composites.     

绿色复合材料的研究进展

天然植物纤维具有价廉质轻、比强度高和自然降解等优良特性,其与生物降解树脂进行复合,能开发出环境友好、可自然降解的绿色复合材料.本文评述了该领域的研究进展,重点是竹纤维、各种麻纤维以及甘蔗渣纤维等天然纤维与不同的生物降解树脂的绿色复合材料的制备,不同成型方法的探讨,材料各种力学性能的分析比较,以及为了增强材料的力学性能而进行的纤维改性,并展望了绿色复合材料的未来的研究趋势.