热固性聚酰亚胺基体树脂的流变行为

热固性聚酰亚胺基体树脂的流变行为;聚酰亚胺;二苯醚二酐;二苯硫醚二酐;苯乙炔苯酐;流变     

热塑性/热固性聚合物共混体系研究——乙炔端基砜/聚砜共混物的动态固化动力学

近年来,半互穿聚合物网络(SIPN)概念被用来研制能结合热塑性聚合物的加工性和热固性聚合物的高温性能的大分子体系,用于复合材料耐高温树脂基体。例如:乙炔端基酰亚胺低聚物与热塑性聚酰亚胺基SIPN,线性聚酰亚胺与热固性双马来酰亚胺基SIPN以及热塑性树脂与双腈基SIPN已有报道。研究结果表明共混物起到协同作用,易于加工并具有优异的性能。乙炔端基砜(ATS)树脂具有与聚砜树脂相类似的结构,被认为在将来代替环氧用于高性能粘合剂和复合材料树脂基体的候选者之一。其另     

耐高温聚酰亚胺树脂研究

综述了耐高温聚酰亚胺树脂及其碳纤维增强复合材料、耐高温聚酰亚胺超级工程塑料和高性能功能性聚酰亚胺薄膜等的研究进展。耐高温聚酰亚胺树脂包括第一代耐316℃系列、第二代耐371℃系列、第三代耐426℃3个系列的产品;耐高温聚酰亚胺超级工程塑料包括反应性热模压成型和高温注塑成型的材料;高性能聚酰亚胺薄膜包括透明性聚酰亚胺薄膜和抗原子氧PI薄膜树脂。本文介绍了它们的结构,工艺以及性能,并对其在航天、航空空间技术及微电子等其它领域中的应用情况做了简单的介绍。     

硬质闭孔聚酰亚胺结构泡沫的结构调控与性能

通过调控聚酰亚胺(PI)树脂主链结构中二苯羰基链段与不对称联苯链段的含量比例,制备了具有不同羰基含量的PI前驱体固体树脂。这些前驱体树脂都具有良好的熔融性,当加热至320~330℃时,PI树脂完全熔融形成低粘度熔体树脂;进一步提高加热温度时树脂熔体粘度由于发生交联反应而急剧增大。将前驱体树脂经加热发泡形成的热固性硬质闭孔PI泡沫具有很高的闭孔率(86%)和耐热性能(Tg353℃,T10519℃)。研究发现,在PI树脂主链结构中引入二苯甲酮链段可明显提高PI泡沫的韧性,而不会牺牲其力学强度和模量。     

可溶性聚酰亚胺共聚物的制备及其性能

通过共缩聚及改变单体加料顺序和方法,得到了两系列共聚型聚酰亚胺,并应用Fr-IR、UV、X射线衍射、TGA、机械性能测试等方法,对所得聚酰亚胺树脂的性能进行了表征。结果表明,所得共聚型聚酰亚胺树脂成膜性能良好,能够得到坚韧且具有弹性的薄膜材料,其在400～450nm区域的透过性能良好,在有机溶剂中的溶解性能显著增强,并保持了聚酰亚胺特有的良好机械性能及耐热性能。     

含三氟甲基聚酰亚胺的合成与性能研究

通过在4,4′-二氨基二苯醚(4,4-′ODA)单体中引入三氟甲基合成了一种新型二胺单体2-三氟甲基-4,4′-二氨基二苯醚(3FODA),该单体具有良好的溶解性和高的反应活性,使用3FODA替代4,4′-二氨基二苯甲烷(MDA)制备了PMR热固性聚酰亚胺树脂.树脂溶液高浓度低粘度,具有室温下良好的储存稳定性;树脂具有很好的加工性能,成型后的模压件显示了优异的热性能和耐热氧化稳定性,玻璃化转变温度在336~379℃之间;此外树脂具有较好的电性能和较低的吸水率.     

低热膨胀聚酰亚胺薄膜的研究进展与展望

聚酰亚胺是一种很有发展前途的高分子材料,热膨胀系数高的问题限制了聚酰亚胺的应用,降低热膨胀系数已成为聚酰亚胺研究热点之一。本文概述了国内外关于降低聚酰亚胺薄膜热膨胀系数的主要方法:分子结构设计法、共聚法、树脂共混法、添加纳米粒子法。阐述了工艺因素(如涂膜方式、牵伸条件等)对聚酰亚胺热膨胀系数的影响,并对未来低热膨胀系数聚酰亚胺薄膜的发展方向进行了展望。     

可持续热固性树脂的高性能和功能化设计合成

传统热固性树脂的大量使用与石化资源的枯竭和环境恶化之间的矛盾日益突出,使得高性能热固性树脂的可持续发展正面临着严峻的挑战.以可再生资源替代传统的石油化工产品用于生物基热固性树脂的合成,是实现其绿色化的重要方式之一.除此以外,如何赋予生物基热固性树脂良好的使役性能、复杂应用环境下的多功能性、高效且高质的可回收再利用性,也...     

热塑性聚酰亚胺及其改性材料的制备与性能

聚酰亚胺具有优异的耐高温性能,但其熔融、加工性能较差,限制了其广泛应用。通过在聚酰亚胺分子结构中引入柔性基团、设计分子结构的异构化等方法,可制备热塑性聚酰亚胺,使得其加工性能得到改善,并可通过挤出、注塑等成型加工。本文在对热塑性聚酰亚胺单体及其树脂的合成方法进行综述的基础上,讨论了热塑性聚酰亚胺改性尼龙、聚醚醚酮、环氧树脂等材料的制备方法和性能特点,并对聚酰亚胺改性工程塑料的未来发展方向进行展望。     

应用扭辫分析技术研究环氧树脂的固化行为

热固性树脂作为固体材料使用,具有优良的工程特性,如尺寸稳定性好、耐溶剂性好、强度和耐热性较高等。但是以往对材料性能有直接影响的树脂固化过程,却未能得到充分的研究。主要是由于热固性树脂的固化过程从低分     

乙炔基封端聚酰亚胺增韧改性的相结构

以双酚A二醚二酐(BPADA)和3乙-炔苯胺(APA)为原料,通过两步法合成一种热固性可交联的聚酰亚胺预聚体.将此预聚体分别与不同结构的热塑性聚酰亚胺(PI)共混,对其进行增韧改性,通过调控热塑性聚酰亚胺的质量分数,引入结构相似且含有更多柔性基团的热塑性聚酰亚胺(如含有醚键和对称甲基结构的二酐),得到了热固/热塑性聚酰亚胺复合膜.利用差示扫描量热仪(DSC)及扫描电镜(SEM)对该体系的相分离结构和相容性进行研究,并讨论其机械性能和热性能.结果表明,相分离结构使体系的机械性能得到改善,同时也保持了原有的优异热性能.     

含氟聚酰亚胺及其在微电子工业中的研究进展Ⅱ含氟聚酰亚胺在微电子工业中的应用

综述了近年来国内外在含氟聚酰亚胺(PI)研究及应用领域中的最新进展情况。主要从现代微电子工业对相关材料的性能要求、标准型聚酰亚胺材料所面临的挑战以及新型含氟聚酰亚胺在微电子工业中的应用等几个方面进行了详细的综述。重点阐述了中国科学院化学研究所305组近几年在这方面的研究进展情况。并指出为了推动我国微电子工业的发展，研制开发低成本、高技术含量的含氟聚酰亚胺材料具有十分重要的现实意义．     

含氟聚酰亚胺及其在微电子工业中的研究进展I含氟单体及聚酰亚胺的合成

综述了近年来国内外在含氟聚酰亚胺(PI)研究及应用领域中的最新进展情况。主要从含氟二胺单体、二酐单体及含氟聚酰亚胺在合成方面的研究进展情况进行了详细的综述。重点阐述了中国科学院化学研究所305组近几年在这方面的研究进展情况，并指出为了推动含氟聚酰亚胺这类具有优良综合性能的功能材料在工业上的广泛应用，就必须首先解决含氟单体种类较少这个制约含氟聚酰亚胺发展的瓶颈问题。     

Dielectric relaxation in a thermosetting polyimide modified with a thermoplastic polyimide

Relaxation processes in glass-fiber-reinforced composites with a polymer matrix based on blends of thermosetting and thermoplastic polyimides are studied via dielectric-relaxation spectroscopy. For all investigated blends, two relaxation processes related to the β relaxation of different fragments of the polymer chain are found. Linear flexiblechain polyimide incorporated into the polymer matrix serves as a plasticizer.     

Recent development on bio-based thermosetting resins

Due to the rapid depletion of crude oil and serious environmental pollution, the synthesis of polymers from renewable resource is becoming more and more important. Up to now, a great variety of biomass and bio-based platform compounds have been taken to prepare the polymers. However, as two representative thermosetting resins, epoxy and benzoxazine resin derived from renewable feedstocks only obtain limited attention compared with the popular bio-based plastics, including PLA, PBAT and PHBV etc. The reason might be that the properties of previously reported thermosetting resins directly obtained from biomass are usually unsatisfied, and their application fields are limited. In this paper, the latest development on the synthesis of high-performance bio-based epoxy and polybenzoxazine resins are reviewed. In addition, to further broaden their applications, the functionalization strategies are also summarized. The objective of this work is to help us fully aware the present situation of bio-based thermosetting resins and then promote their faster development, especially practical application.     

4-苯乙炔苯酐封端聚酰亚胺树脂的合成与性能研究

使用3,3′,4,4′-二苯醚四酸二酐(ODPA)、3,3′,4,4′-联苯四酸二酐(BPDA)、1,3-双(4-氨基苯氧基)苯(1,3,4-APB)、3,4′-二氨基二苯醚(3,4′-ODA)和反应性封端剂4-苯乙炔苯酐(4-PEPA)合成了设计分子量为5000的系列苯乙炔基封端的聚酰亚胺低聚物,并使用XRD、DSC、TGA、FT-IR、DMA和流变仪等对低聚物的化学结构、热性能和熔体性能,固化后树脂的热性能和力学性能进行了测试.研究结果表明基于ODPA的低聚物具有低的熔体粘度和良好的熔体粘度稳定性,固化后的树脂具有很高的热失重温度,较高的玻璃化转变温度以及良好的力学性能尤其是高的断裂伸长率(>10%);基于BPDA的低聚物具有一定的结晶性,其结晶熔融温度与苯乙炔基固化交联温度相近,影响了材料的成型工艺性能.     

Thermosetting polyimides

Linear polyimides prepared from m-phenylene diamine (MPD) and 3,4,3′,4′-benzophenonetetracarboxylic dianhydride (BTDA) were modified so as to be thermosetting. This was done by replacing a portion of the MPD with either 2,4-diaminoacetanilide or p-(2,4-diaminophenoxy) acetanilide and 3,5-diaminobenzoic acid; it is thought that during final processing of the laminates the carboxyl group and the acetamido group react, forming amide crosslinks. Alternatively, excess anhydride was incorporated into the polymer to react with some of the attached acetamido groups; these would give imide crosslinks. A series of resins and glass-reinforced laminates incorporating these resins was prepared. The laminates were aged and tested at 315°C. Flexural strength at 315°C. versus hours aged at 315°C. is presented. Flexural strength after 100 hr. at 315°C. for two of the better laminates from modified polymers was about 48,000 psi, compared to 24,000 psi for the straight linear polymer. The flexural strength of the modified polymers decreased more rapidly, however, and after 1000 hr. of aging at 315°C. the flexural strength of the best laminates, including the linear polymer, was 12,000 psi.     

Investigations of the Rheology and Reactivity of Extrudable Wood-Resin Compounds

Summary. The extrusion of wood composites based on thermosetting resins is a new application in the field of wood plastic composites. To enable the extrusion of wood thermosetting compounds, it is necessary to know their reactivity and rheology well beforehand, to prevent the system curing inside the extruder. This study shows the different techniques that were adapted to allow in combination an estimation of the processing behaviour of wood-resin compounds in extrusion.     

Fully aromatic macrocycle‐terminated polyimide: synthesis and cross‐linking

This study reported a method to prepare fully aromatic macrocycle‐terminated polyimides (MC‐PI). The macrocycle of aryl ether ketones was prepared from (4‐amino)phenylhydroquinone and a di‐fluoro monomer under pseudo high dilution condition. Novel aromatic fully MC‐PI oligomers were successfully prepared by the reaction of 2,3,3′,4′‐biphenyltetracarboxylic diandhydride with 2,5‐bis(4′‐aminophenoxy)‐biphenyl and sulfur‐containing macrocycle of aryl ether ketone. The MC‐PI oligomers were cross‐linkable in the heating, and the glass transition temperatures of the polyimides increased after thermally cured. The cross‐linking reaction of MC‐PI could form fully aromatic thermosetting polyimide by ring‐opening reaction. After cross‐linking, these polyimides showed higher glass transition temperatures and excellent thermal stability. Copyright © 2013 John Wiley & Sons, Ltd.     

Investigations of the Rheology and Reactivity of Extrudable Wood-Resin Compounds

The extrusion of wood composites based on thermosetting resins is a new application in the field of wood plastic composites. To enable the extrusion of wood thermosetting compounds, it is necessary to know their reactivity and rheology well beforehand, to prevent the system curing inside the extruder. This study shows the different techniques that were adapted to allow in combination an estimation of the processing behaviour of wood-resin compounds in extrusion.