光敏聚酰亚胺的进展及其在光纤涂料中的应用

概述了负性光敏聚酰亚胺的研究进展和光纤涂料当前研究的热点,提出了将负性光敏聚酰亚胺用于耐高温光纤涂料的新设想。     

有机硅改性聚酰亚胺

<正> 聚酰亚胺(PI)是一种耐热性、电气特性、机械特性优异的树脂,它具有其它材料无法比拟的强度、耐磨性以及优良的耐高温性能,所以很适合高性能的应用领域。而完全亚胺化的这类聚合物通常是不溶不熔的,给加工带来了困难。为了改善加工性或赋予粘接性,国外近几年来在PI改性方面进行了大量的研究,通过改变PI     

聚酰亚胺的改性及应用研究

聚酰亚胺具有突出的耐温性能,优异的电学和机械性能,是目前耐温性最高和综合性能最优异的树脂高分子材料之一。本文详细介绍了聚酰亚胺的分类、改性方法、应用及其发展动向。     

聚酰亚胺合成及改性的研究进展

主要介绍了聚酰亚胺(PI)的合成方法,包括通过在聚合过程中或在大分子反应中形成酰亚胺环,或通过已含有酰亚胺环的单体聚合成PI.阐述了改性PI的几种方法,包括结构改进、共混改性、共聚改性和填充改性.针对PI合成工艺和改性中存在的问题,提出了发展前景.     

改性聚酰亚胺在摩托车中的应用

本研究选择了改性聚酰亚胺、改性聚甲醛、改性尼龙三种材料应用于摩托车衬套制品,进行了对比试验,结果表明:采用改性聚酰亚胺的衬套具有强度高、耐磨损、尺寸稳定性好等特点,完全达到该产品设计的要求。     

聚酰亚胺的改性研究进展

综述了聚酰亚胺改性方面的内容。聚酰亚胺具有高强高模、耐辐射、绝缘好等特性,加工流动性及溶解性不佳、易水解等悬其不足。对聚酰亚胺合成改性、结构改性或与其他材料复合后,其原有的一些缺点得到了改善,并赋予了新的功能。另对聚酰亚胺的应用前景做了展望。     

工程塑料改性及成型加工技术特集之九聚酰亚胺的改性及应用

本文介绍具有目前Tg最高达250℃的聚酰亚胺AURUM的特性、地位、材料开发和用途开发,特别是利用其Tg高的特性,不断进入机械部件、滑动部件、半导体部件领域的应用.     

聚酰亚胺的改性及应用

本文介绍具有目前Tg最高达250℃的聚酰亚胺AURUM的特性、地位、材料开发和用途开发，特别是利用其Tg高的特性，不断进入机械部件、滑动部件、半导体部件领域的应用。     

聚酰亚胺的改性研究新进展

综述了近几年聚酰亚胺的改性方法的研究状况。     

聚酰业胺树脂生产和用进展

介绍了聚酰亚胺（PI）的性能、用途、合成方法,国内外研究开发现状及发展前景,指出了其今后的发展趋势。     

Surface modification of polyimide films via plasma polymerization and deposition of allylpentafluorobenzene

Plasma polymerization of allylpentafluorobenzene (APFB) on the plasma-pretreated polyimide (PI) films was carried out. The fluorinated aromatic groups of the plasma-polymerized APFB (pp-APFB) could be preserved, to a large extent, by controlling the glow discharge parameters. The effect of the glow discharge parameters, including the type of the carrier gas and the input RF power, on the surface composition and chemical structure of the pp-APFB films were studied by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and time-of-flight secondary ion mass spectrometry. The surface topography of the APFB plasma-polymerized PI (pp-APFB-PI) films was studied by atomic force microscopy. For plasma polymerization carried out at a high RF power and using argon as the carrier gas, an ultra-hydrophobic pp-APFB-PI surface was also obtained. The ultra-hydrophobic surface exhibited advancing/receding water contact angles (θ_A/θ_R) of 174°/135°. The effectiveness of the carrier gas in defluorinating the pp-APFB films followed the order of O₂>N₂>H₂>Ar. Thus, the role of the carrier gas in improving the surface hydrophobicity of the resulting pp-APFB-PI films followed the order of O₂22® tape adhesion test.     

Enhanced performances of polypropylene membranes by molecular layer deposition of polyimide

Molecular layer deposition(MLD) for the deposition of polyimide(PI) at low temperature of 110 °C has been firstly introduced into the field of membrane separation. With the optimized MLD deposition parameters, such low deposition temperature has successfully expanded the application of MLD for the surface modification of polymeric materials. Globular PI particulates grow on both the free surfaces as well as the pore walls of the polypropylene(PP) membranes as isolated islands during progressive precursor exposures. The PI-deposited PP membranes exhibit synergistically improved performances in various aspects. Evidently improved surface hydrophilicity and permeation performance(30%) have been achieved via the MLD deposition of polyimide films. The overall separation efficiency maintained higher than 85% even after 250 cycles of MLD deposition. More importantly, the thermal stability has been improved and the integrity of the porous structure for PI-deposited PP membranes has been well preserved even after harsh treatment, which ensures its potential application in industries.     

聚酰亚胺的研究进展及应用

本文简单介绍了聚酰亚胺的合成及改性的研究,同时也介绍了聚酰亚胺在航空、航天以及电子领域的应用进展。     

Preparation and characterization of polyimide/organoclay nanocomposites

Organically modified montmorrillonite clay, containing a long chain aliphatic quarternary ammonium cation, was used to prepare polyimide/organoclay hybrids. Several approaches were examined in an attempt to achieve fully exfoliated nanocomposites. These included simple mixing of the clay in a pre-made high molecular weight poly(amide acid) solution; simple mixing followed by sonication of the organoclay/poly(amide acid) solutions; and the preparation of high molecular weight poly(amide acid)s in the presence of the organoclay dispersed in N-methyl-2-pyrrolidinone (NMP). The best results were obtained using the in-situ polymerization approach. The resulting nanocomposite films (both amide acid and imide), containing 3-8% by weight of organoclay, were characterized by differential scanning calorimetry (DSC), dynamic thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thin film tensile properties. A significant degree of dispersion was observed in the nanocomposite films of the amide acid and the imide. After thermal treatment of amide acid films to effect imidization, in both air and nitrogen, the films were visually darker than control films without clay and the level of clay dispersion appeared to have decreased. In the latter case, the separation between the layers of the clay decreased to a spacing less than that present in the original organoclay. These observations suggest that thermal degradation of the aliphatic quarternary ammonium cation occurred likely during thermal treatment to effect imidization and solvent removal. These thermal degradation effects were less pronounced when thermal treatment was performed under nitrogen. The polyimide/organoclay hybrid films exhibited higher room temperature tensile moduli and lower strength and elongation to break than the control films.     

A study on the application of UV curing ink with sulfonate type acid amplifier

In this paper, both mono-type: 4-hydroxycyclohexyl-4-vinylbenzenesulfonate(CHDv-m), 4-(4-hydroxycyclo-hexyl) cyclohexyl-4-vinylbenzenesulfonate(BCDv-m), 4-(2-(4-hydroxycyclohexyl)propan-2-yl)-cyclohexyl-4-vinyl-benzenesulfonate(IPDHv-m), 4-hydroxycyclohexyl-4-methylbenzenesulfonate(CHDp-m), 4-(4-hydroxycyclohexyl)-cyclo-hexyl-4-methylbenzenesulfonate(BCDp-m) and 4-(2-(4-hydroxycyclohexyl)propan-2-yl)-cyclohexyl-4-methylbenzene-sulfonate(IPDHp-m) and di-type: 4,4’-di(vinylbenzenesulfonatyl)-cyclohexane(CHDv-d), 4,4’-di(vinylbenzenesulfonatyl)-1,1’-bicyclohexane(BCDv-d), 4,4 ’-di(vinlylbenzenesulfonatyl)-isopropylidene-dicyclohexane(IPDHv-d), 1,4-ditosyloxy cyclohexane(CHDp-d), 4,4’-ditosyloxy-1,1’ -bicyclohexane(BCDp-d) and 4,4’-ditosyloxy isopropylidene dicyclohexane (IPDHp-d) acid amplifiers were synthesized. Their properties were characterized by¹HNMR and DSC measurements. UV curing properties of samples prepared by using novel acid amplifiers were examined by measuring the change of current according to UV radiation time and intensity. Also, the application of acid amplifiers to UV inks was suggested. It was found that UV vehicles and inks with acid amplifier of 4–4’di(vinylbenzenesulfonatyl)-cyclohexane(CHDv-d) had a more rapid degree of curing than other samples.     

Coarse grain modeling of polyimide copolymers

Addressing the wide span of timescales, where various important phenomena takes place in a polymer system, is inconceivable through a typical molecular dynamics simulation. Coarsening of simpler polymer systems has demonstrated significant potential in computationally characterizing and simulating systems at larger timescales. Addressing the need to extend existing coarsening methodologies on multifunctional materials to help design future generation materials is both promising and challenging. In this paper we present development of an atomistically informed coarse grain bead model of piezoelectric polyimide copolymers for large-scale simulations of thermal, mechanical and especially electrical properties. The coarsening approach generated a gain of two and a half orders of magnitude in terms of computational time and an order of magnitude gain in system size (equivalent to ∼ 360,000 atomistic model) while retaining the physical characteristics specific to the piezoelectric polymer. Reasonable agreement was observed between simulation results of the coarse grained and the atomistic model. Specifically mechanical moduli, density, dielectric constant, yield behavior, work hardening, response under dynamic loading and glass transition behavior were analyzed and compared.     

A novel negative photoinitiator-free photosensitive polyimide

A novel negative photoinitiator-free photosensitive polyimide (PFPS-PI) was synthesized through introducing the photosensitive 4,4-bis[(4-amino)thiophenyl] benzophenone (BATPB) into backbone chain and methyl acrylate group into side-chain of the polyimide, respectively. Photosensitive properties study revealed its good photolithographic properties, with a resolution about 5 μm and a sensitivity of 150 mJ/cm².     

Microstructural features, diffusion and molecular relaxations in polyimide/silica hybrids

FTIR spectroscopy has been used to investigate the microstructure of the inorganic phase in polyimide/silica hybrids obtained by the sol-gel route. It has been shown that the presence of a coupling agent (GOTMS) strongly influences the silica phase by favoring the formation of linear, branched chains which make the structure loosely interconnected. The morphological changes induced by GOTMS are reflected in the water sorption properties of the investigated systems. Due to the hydrophilic nature of the silica phase, the amount of sorbed water increases in the hybrid systems in comparison to the pristine polyimide, and among the two hybrids, increases more in the two-phase system than in the co-continuous. Molecular interactions of the hydrogen-bonding type have been identified between the imide units and the H₂O molecules, both in the polyimide and in the hybrid systems. Finally, the sub-T_g relaxation processes have been investigated in detail by dynamic-mechanical analysis coupled with molecular mechanics simulations. Considerable effects of the inorganic phase on these processes were observed, especially for the case of the co-continuous systems, and were accounted for by molecular scale contiguity among the phases.