常压等离子体改性苎麻增强热塑性树脂基复合材料界面性能的研究
发布时间:2018-01-17 21:18
本文关键词:常压等离子体改性苎麻增强热塑性树脂基复合材料界面性能的研究 出处:《东华大学》2015年博士论文 论文类型:学位论文
更多相关文章: 常压等离子体 苎麻 界面性能 复合材料 处理参数 响应面
【摘要】:天然植物纤维增强热塑性树脂基复合材料由于成本低、成型快、轻质高强、抗冲击、耐酸碱及可回收等优点而备受关注。我国天然纤维尤其是麻类纤维资源丰富,其中苎麻产量世界第一,如能将其开发为高附加值的增强纤维很有意义。但是苎麻纤维亲水性的表面与热塑性树脂基体疏水性的表面极性差别大,两者之间相容性差使得其界面粘结性能差,负载不能有效地通过界面传递,造成复合材料整体性能下降。目前常使用的界面改性方法虽能取得一定效果,但是处理效率低、能源消耗高、对纤维损伤大,且废弃物的处理污染环境,不符合当今可持续发展的理念,因此对环境友好、可操作性强、处理效率高且对纤维损伤小的等离子体技术在材料表面改性领域研究中的关注度与日俱增。如能将等离子体技术运用于植物纤维的表面改性,提高植物纤维增强复合材料的界面性能,极有发展前景。 但是,大部分等离子体处理都是在低气压的条件下进行,而抽真空系统成本高,处理不连续,加上抽真空处理对于一些含液体的样品难以实施,使得等离子体技术的应用受到了一定的限制。因而国际上正积极研究不需要真空系统的常压等离子体技术,目前主要有两种:常压等离子体射流(APPJ)和常压介质阻挡放电(DBD)等离子体。 本课题采用常压APPJ和DBD设备,以苎麻纤维和苎麻织物为研究对象,系统地研究了常压等离子体技术对苎麻纤维表面性能的影响;等离子体处理参数对改性效果的交互作用;等离子体对苎麻纤维改性的时效性;等离子体对苎麻织物的改性以及对苎麻织物增强聚丙烯复合材料界面性能及力学性能的影响。围绕该主题,本文开展的主要工作如下: (1)采用常压DBD等离子体对苎麻纤维表面进行改性,选用聚丁二酸丁二醇酯(PBS)为热塑性树脂基体。分别采用扫描电镜(SEM)、原子力显微镜(AFM)、 X射线光电子能谱(XPS)、纤维动态接触角分析(DCAA)以及单纤维拉伸强度测试等考察了等离子体处理对苎麻纤维表面形貌、表面化学成分、表面亲水性能的改变以及对苎麻纤维强度的影响,采用单纤维抽拔测试来检测苎麻纤维与PBS树脂的界面剪切强度(IFSS)。研究结果表明:经等离子体处理后,苎麻纤维表面变得粗糙并出现了许多明显的颗粒、微坑和凸起,增加了纤维表面与PBS的机械锁合作用。纤维表面碳元素含量以及C-C基团含量明显提高,纤维接触角也明显提高,苎麻与PBS树脂间的IFSS值增幅最高约46%,苎麻纤维的拉伸强度没有出现显著性减小。同时发现等离子体处理电压对苎麻纤维的表面改性有显著性影响:当处理电压低于一定阈值时,等离子体对苎麻纤维几乎起不到改性效果;而处理电压过高时,则会破坏改性效果,因此应合理选择等离子体处理参数。 (2)常压等离子体处理参数对材料表面改性效果通常有显著性影响,而等离子体各处理参数对改性效果的影响不是独立的,参数间往往有交互作用。为了研究常压等离子体处理参数对苎麻纤维表面改性效果的综合影响,设计改进了一种新型的常压DBD等离子体设备对苎麻纤维表面进行改性,使用中心复合设计(CCD)响应面法(RSM)对等离子体处理参数进行设计,在单因素实验研究基础上,选定3个影响较大的因素(处理电流、处理时间、乙醇气体流速)作3因素5水平实验来考察处理参数对等离子体改性苎麻纤维的协同作用,共有15组实验处理参数。分别采用场发射扫描电镜(FESEM)、 XPS、 DCAA考察了苎麻纤维表面形貌、表面化学成分及表面亲水性能的变化;由单纤维抽拔测试获得苎麻纤维与聚丙烯树脂基体间的IFSS值;由四极杆质谱分析仪来测试等离子反应室内的气体成分。研究表明:等离子体处理参数间存在交互作用,在处理电流(10mA),处理时间(5min)及乙醇流速(8sccm)的等离子体处理参数下,苎麻与聚丙烯间的IFSS增幅值为最高约为50%,而且流速是对改性效果影响最显著的因素。由质谱分析发现,乙基基团浓度较高的组,其相应的DCAA值和IFSS值也大多比较高,说明乙基的浓度与等离子体对苎麻纤维的改性效果紧密相关。此外,本实验中在原有的气体通道外另增加了一个通道,这种对传统等离子体设备的改良方法可以控制和按需调节处理气体成分比,对提高等离子体处理效果的重复性和稳定性很有帮助。 (3)常压等离子对材料表面改性的主要问题是等离子体的时效性,即改性后的材料表面状态会慢慢回复到未改性水平。由于改性后的材料在等待应用过程中还可能会经过相当长的一段时间,因此时效性研究成为了等离子体对材料表面改性研究领域必不可少的内容。为了进一步研究常压等离子体对苎麻纤维的表面改性效果是否存在时效性,使用常压等离子体射流(APPJ)设备对苎麻纤维表面进行处理,并在150天内每隔一定时间分别对纤维进行测定,采用SEM、XPS、纤维接触角测试等分析技术考察苎麻纤维的表面形貌、表面化学成分及表面亲水性能的变化;采用单纤维抽拔测试对苎麻纤维及聚丙烯树脂间的IFSS值进行测定;并采用SEM对单纤维抽拔测试后的苎麻纤维表面脱粘区域形貌进行分析。研究表明:在150天内,苎麻纤维表面化学成分中碳氧元素及各基团的含量较为稳定,而表面亲水性、苎麻/聚丙烯的IFSS值以及苎麻纤维脱粘形貌未见明显变化,即常压等离子体处理将亲水性的苎麻表面改性为疏水性后,其表面未见明显的亲水性回复,因此常压等离子体处理可被用作一种改性效果较为稳定和持久的材料表面改性方法。 (4)使用常压DBD等离子体对苎麻织物表面进行改性,使用热压法制备苎麻织物增强聚丙烯复合材料板,以研究常压等离子体改性前后苎麻织物表面性能以及其增强聚丙烯复合材料界面性能和力学性能的改善。采用SEM、XPS、表面接触角测试来分别考察苎麻织物的表面形貌、化学成分及表面亲水性能的变化;并采用SEM来观察经层间剪切强度(ILSS)测试后的织物表面脱粘区域形貌;采用ILSS测试、弯曲强度测试和拉伸强度测试来分别检测等离子体改性前后的复合材料剪切性能、弯曲性能和拉伸性能。通过SEM分析发现,经常压等离子体改性后,苎麻纤维表面粗糙度增加,改性后的苎麻织物增强聚丙烯复合材料的界面剪切破坏模式由粘合破坏转变为了内聚破坏,剪切破坏区域纤维表面粘附了大量聚丙烯树脂,纤维与树脂基体间的结合性能改善,是较为理想的界面破坏模式。通过XPS和接触角测试表明,常压等离子体处理后苎麻织物表面的碳元素比例大幅度上升,氧碳元素比例降低,苎麻织物表面接触角明显增加,表明等离子体处理在苎麻织物表面引入了疏水性基团。复合材料的力学性能测试表明,改性后苎麻织物增强复合材料的层间剪切强度、弯曲强度和拉伸强度都有显著提高,提高幅度最高分别为39%,28%和20%。
[Abstract]:The natural plant fiber reinforced thermoplastic resin based composite materials because of low cost, fast molding, light weight and high strength, impact resistance, acid and alkali and Recyclable has attracted attention. The natural fiber in China especially the bast fiber is rich in resources, the ramie production in the world, such as the development of high value-added fiber is of great significance. But the surface hydrophilicity of ramie fiber and thermal plastic surface of the resin matrix of hydrophobic polar difference, between the poor compatibility of the poor interface bonding performance, load can be transferred effectively through the interface, resulting in a decline in the overall performance of the composite material. The modification methods often used at present although the interface can be achieved a certain effect, but low efficiency, high energy consumption, damage to fiber, and the disposal of waste pollution of the environment, do not accord with the concept of sustainable development, so the environmental friendly, strong operability, Processing efficiency is high and the degree of concern grow with each passing day of fiber damage on plasma technology in the field of surface modification as can use surface plasma technology in plant fiber modification, to improve the interface properties of composite materials of plant fiber, it has great development prospects.
However, most of the plasma processing is carried out in low pressure conditions, and vacuum system of high cost, processing is not continuous, and vacuum treatment for some liquid samples is difficult to implement, the application of plasma technology is limited. The international community is actively studying the atmospheric plasma technology without vacuum system at present, there are two main types: atmospheric pressure plasma jet (APPJ) and atmospheric dielectric barrier discharge (DBD) plasma.
The atmospheric pressure APPJ and DBD equipment to ramie fiber and ramie fabric as the research object, systematically studied the influence of atmospheric pressure plasma technology on the surface properties of ramie fiber; plasma treatment parameters on the interaction effect of modification; plasma modification of effectiveness of ramie fiber; plasma on ramie fabric modification and the ramie fabric reinforced polypropylene composite interfacial properties and mechanical properties. On the subject, the main work carried out as follows:
(1) the modification of ramie fiber surface atmospheric DBD plasma, using poly butylene succinate (PBS) is a thermoplastic resin matrix, respectively. Using scanning electron microscopy (SEM), atomic force microscopy (AFM), X ray photoelectron spectroscopy (XPS) analysis, fiber (DCAA) and dynamic contact angle the single fiber tensile strength test and other effects of the plasma treatment on the surface morphology of ramie fiber, surface chemical composition, surface hydrophilicity and change of ramie fiber strength, single fiber pull-out test to detect the interfacial shear strength of ramie fiber and PBS resin (IFSS). The results showed that after plasma treatment, ramie the fiber surface becomes rough and there are many obvious particles, micro holes and bumps, increase the fiber surface and the PBS mechanical locking effect. The surface content of carbon fiber and the content of C-C groups increased significantly, the fiber The antennae were significantly increased, ramie and PBS resin IFSS values between the highest growth rate of about 46%, the tensile strength of ramie fibers did not appear significantly reduced. At the same time that the plasma treatment voltage on the surface of ramie fiber modification had a significant effect: when the applied voltage is lower than a certain threshold, plasma almost of ramie fiber not modified the effect of processing; and the voltage is too high, it will destroy the modification effect, it should be a reasonable choice of plasma treatment parameters.
(2) atmospheric plasma treatment parameters often have a significant impact on the material surface modification effect, and the effect of processing parameters on the plasma modification effect is not independent, often have interaction parameters. In order to study the atmospheric plasma treatment parameters on the comprehensive effect of ramie fiber surface modification effect, improved design modification on the surface of the ramie fiber is a new type of atmospheric DBD plasma devices, using central composite design (CCD) response surface method (RSM) to design the plasma processing parameters, based on single factor experiment, selected 3 influence factors (current treatment, treatment time, gas flow rate of 3 ethanol) 5 factors to investigate the synergistic effect level of experimental treatment parameters on plasma modification of ramie fiber, a total of 15 experiments. The processing parameters respectively by field emission scanning electron microscopy (FESEM), XPS, DCAA were investigated The surface morphology of ramie fiber, changes in surface chemical composition and surface hydrophilicity; pull test pumping by the single fiber matrix of ramie fiber and polypropylene resin between the IFSS value; by quadrupole mass analyzer to test gas plasma reaction chamber component. The study shows that the plasma processing parameters interaction, in dealing with the current (10mA), treatment time (5min) and ethanol (8sccm) velocity of plasma treatment parameters, ramie and polypropylene between IFSS growth is the highest value is about 50%, and the flow rate is the most significant factor modification effect. By mass spectrometry analysis showed that the ethyl radical concentration group, the corresponding DCAA and IFSS values are relatively high, indicating modification effect and plasma concentration of ethyl of ramie fiber is closely related. In addition, this experiment in the gas channel outside the original added a channel, The improved method of traditional plasma equipment can control and adjust gas composition ratio on demand, which is very helpful for improving repeatability and stability of plasma treatment effect.
(3) plasma is the time of the main problem of plasma surface modification of materials, the material surface modification state after getting back to the unmodified level. Due to the modified material in the process of waiting for the application may also after quite a long period of time, so the study of timeliness become plasma surface modification of materials research in the field of essential content. In order to further study the existence of the timeliness of the atmospheric pressure plasma of ramie fiber surface modification effect, the use of atmospheric pressure plasma jet (APPJ) equipment of ramie fiber surface treatment, and in every 150 days within a certain time of fiber were measured by SEM, XPS fiber contact angle testing, analysis of technical investigation of ramie fiber surface morphology, changes in surface chemical composition and surface hydrophilicity; single fiber pull-out test of ramie fiber IFSS and polypropylene resin between the value determination; and adopting SEM debonding area of ramie fiber surface morphology of single fiber pull-out test after analysis. The study shows that in 150 days, the content of oxygen and carbon fiber surface chemical composition elements of ramie and each groups is relatively stable, while the surface hydrophilicity, ramie / polypropylene IFSS value and ramie fiber debonding morphology did not change obviously, the atmospheric pressure plasma treatment of ramie surface hydrophilic modification of hydrophobic and hydrophilic surface no reply the obvious, so the atmospheric pressure plasma treatment can be used as a surface modification effect is stable and lasting modification method.
(4) the use of atmospheric DBD plasma on ramie fabric surface modification, preparation of ramie fabric reinforced polypropylene composite plate using hot pressing method, to study the atmospheric pressure plasma treatment of ramie fabric surface properties and improve its reinforced polypropylene composite interfacial properties and mechanical properties. By using SEM, XPS, surface contact angle test respectively to analyze the surface morphology of ramie fabric, changes in chemical composition and surface hydrophilicity; and to observe the interlaminar shear strength by SEM (ILSS) testing fabric surface after debonding area morphology; using ILSS test, flexural strength test and tensile strength test to detect the shear properties of the composites before and after plasma treatment the respectively, flexural strength and tensile strength. The SEM analysis showed that often pressure after plasma modification of ramie fiber, the surface roughness increases, the modified ramie fabric reinforced The interfacial shear failure mode of polypropylene composites by adhesion damage to cohesive failure, shear failure area of fiber surface adhesion of polypropylene resin combination between the fiber and the matrix performance, is the ideal interface failure mode. Through XPS and contact angle test showed that the carbon ratio greatly after atmospheric pressure plasma treatment of ramie fabrics the surface of the rising oxygen carbon ratio decreased, the ramie fabric surface contact angle increased significantly, that in plasma processing of ramie fabric was introduced to the surface of hydrophobic groups. The mechanical properties of composite materials showed that the modified ramie fabric reinforced composite interlaminar shear strength, bending strength and tensile strength are increased significantly and the highest increase rate were 39%, 28% and 20%.
【学位授予单位】:东华大学
【学位级别】:博士
【学位授予年份】:2015
【分类号】:TB332
【参考文献】
相关期刊论文 前1条
1 王春霞;邱夷平;;常压等离子射流处理对羊毛织物正反面染色性的影响[J];纺织学报;2007年11期
相关博士学位论文 前2条
1 孙洁;常压等离子体处理高分子材料诱导自由基及其引发表面改性反应的研究[D];东华大学;2011年
2 贾彩霞;空气DBD等离子体对芳纶表面及其增强复合材料界面的改性研究[D];大连理工大学;2012年
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