含硅聚酰亚胺的合成与性能

含硅聚酰亚胺由于具有可溶性、粘合性、吸湿性以及电绝缘性等方面的优势,近年来逐渐成为聚酰亚胺改性研究的热点。本文主要综述了近年来主链型含硅聚酰亚胺、侧链型含硅聚酰亚胺以及聚酰亚胺含硅无机复合材料的合成方法及其改性性能,并对含硅聚酰亚胺的研究发展进行了展望。     

含硅聚酰亚胺的合成与性能

介绍了含硅聚酰亚胺的若干不同合成和改性方法及相应产物的性能特点.     

含硅聚酰亚胺的发展现状

近年来各种含硅聚酰亚妥相继开发,它既保持了聚酰亚胺的耐热及电气性能,又具有有机硅的溶解性,良好的粘接性及低吸湿性。其主要用于微电子工业,宇航及印刷线路工业等。本文侧重介绍了聚硅氧烷－聚酰亚胺嵌段共聚物。     

新型含吡啶环芳香二胺及其可溶性聚酰亚胺的合成与表征

以苯甲醛和3-(4-硝基苯氧基)苯乙酮(NPAP)为原料,通过改进的Chichibabin反应制备了硝基化合物4-苯基-2,6-双[3-(4-硝基苯氧基)苯基]吡啶(PNPP),再用Pd/C和水合肼将PNPP进行还原,成功制备了一种新型含吡啶环的芳香二胺4-苯基-2,6-双[3-(4-胺基苯氧基)苯基]吡啶(PAPP)。以PAPP作为二胺,3,3′,4,4′-二苯醚四羧酸二酐(ODPA)作为二酐,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,经热或者化学亚胺化形成聚酰亚胺,制得了一种新型的含吡啶环聚酰亚胺。所得聚酰胺酸和聚酰亚胺的粘度分别为0.59 dL/g和0.56 dL/g。化学亚胺化所得的聚酰亚胺速溶于常见有机溶剂如DMF、N,N-二甲基乙酰胺(DMAc)、N-甲基-2-吡咯烷酮(NMP)、四氢呋喃(THF)等。制得了柔韧的聚酰亚胺膜,膜有很好的热稳定性,玻璃化转变温度(T_g)为230.8℃,氮气氛中10%失重温度为552.0℃,同时,膜还有较好的力学性能,拉伸强度为88.6 MPa,拉伸模量为1.04 GPa,断裂伸长率为8.7%,膜的吸水率为0.89%。     

化学亚胺化合成含吡啶环共聚聚酰亚胺

用2,2-双[4-（4-氨基苯氧基）苯基]丙烷（BAPP）和4-苯基-2,6-双（4．氨基苯基）吡啶（PBAP）作为二胺,3,3’,4,4＇-二苯酮四酸二酐（BTDA）作为二酐,以N,N-二甲基甲酰胺（DMF）为溶剂,合成了3种聚酰亚胺。先用BAPP和PBAP同BTDA反应生成一系列聚酰胺酸（PAA）,然后将得到的PAA用化学亚胺化制备相应的聚酰亚胺。用FT-IR、^1H—NMR、粘度测试、溶解性测试和TGA对聚合物的结构和性能进行了表征。结果表明,FT—IR测试在1780cm^-1、1720cm^-1和725cm^-1左右出现了聚酰亚胺的特征吸收峰,所得聚酰胺酸的特性粘数为0．32～0．46dL／g,大部分聚酰亚胺在常见有机溶剂NMP中可溶,它们有很好的热稳定性,氮气氛中,在500℃以前没有明显的降解。     

硅二极管内层聚酰亚胺保护胶的研制

由聚硅氧烷二胺、芳香族二胺、芳香族二酐溶液缩聚合成的含硅聚酰亚胺应用于硅二极管内层绝缘保护,显示出良好的应用前景。     

PAPP/ODA共聚聚酰亚胺的制备与性能

以4–苯基–2,6–双[4–(4–氨基苯氧基)苯基]吡啶和4,4′–二氨基二苯醚为二胺单体,3,3′,4,4′–二苯酮四羧酸二酐为二酐单体,N–甲基–2–吡咯烷酮为溶剂,通过一次加料,得到共聚聚酰亚胺。用傅立叶变换红外光谱仪、差示扫描量热仪、热重分析仪、X射线衍射仪、溶解性测试等对共聚聚酰亚胺的结构和性能进行了表征。研究结果表明,所得聚合物在1 780,1 723,1 380 cm-1左右出现了聚酰亚胺的特征吸收峰,实验所得的聚酰亚胺能很好地溶解在常见有机溶剂中,玻璃化转变温度为246℃,氮气气氛中,10%的热失重温度为505℃,800℃的残余率为48%。     

新型含吡啶环二胺及其可溶透明性氟化聚酰亚胺的合成与表征

以4-三氟甲基苯甲醛和3-(4-硝基苯氧基)苯乙酮(m,p-NPAP)为原料,通过改进的Chichibabin反应制备了硝基化合物4-(4-三氟甲基苯基)-2,6-双[3-(4-硝基苯氧基)苯基]吡啶(m,p-3FPNPP),再用Pd/C和水合肼将m,p-3FPNPP进行还原,成功制备了一种新型含吡啶环的芳香二胺4-(4-三氟甲基苯基)-2,6-双[3-(4-胺基苯氧基)苯基]吡啶(m,p-3FPAPP)。以m,p-3FPAPP作为二胺,3,3′,4,4′-二苯醚四羧酸二酐(ODPA)作为二酐,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,经热或者化学亚胺化形成聚酰亚胺,制得了一种新型的含吡啶环聚酰亚胺。所得聚酰胺酸和聚酰亚胺的粘度分别为0.78 dL/g和0.65 dL/g。化学亚胺化所得的聚酰亚胺速溶于常见有机溶剂如DMF、N,N-二甲基乙酰胺(DMAc)、N-甲基-2-吡咯烷酮(NMP)、四氢呋喃(THF)等。制得了柔韧的聚酰亚胺膜,膜有很好的热稳定性,玻璃化转变温度(Tg)为234.4℃,氮气氛中10%失重温度为575.3℃,膜有很好的光学透明性,截止波长为369 nm,同时,膜还有较好的力学性能,拉伸强度为96.4 MPa,拉伸模量为1.63 GPa,断裂伸长率为9.2%,膜的吸水率为0.68%。     

含氟聚酰亚胺的设计、合成及应用性能研究进展

聚酰亚胺作为结构独特的一类功能性高分子材料,应用广泛.随着人们对材料综合性能要求的提高,含氟聚酰亚胺颇受业界关注.聚酰亚胺结构中引入氟原子既能提高材料溶解性和透光率,还能降低其吸湿率和介电常数.综述了近年来含氟聚酰亚胺在设计、合成和应用性能方面的研究进展,指出其结构设计带来的性能优势.特别是对含氟聚酰亚胺的溶解性、光学...     

含吡啶环二胺及其可溶性聚酰亚胺的制备与表征

以对羟基苯乙酮和苯甲醛为原料,通过亲核取代反应、改进的Chichibabin反应和水合肼催化还原合成了一种新型含吡啶环的芳香二胺4-苯基-2,6-双[4-(4-胺基苯氧基)苯]吡啶(ρ-PAPP),以N,N-二甲基甲酰胺(DMF)为溶剂,将ρ-PAPP与双酚A型二酐（BPADA）通过2步法合成了含吡啶环的新型聚酰亚胺。用红外光谱、差示扫描量热分析、热重分析、X射线衍射、溶解性测试等对聚合物的结构和性能进行了表征。结果表明,所得聚合物在1780、1723、1376 cm-1左右出现了聚酰亚胺的特征吸收峰;实验所得的聚酰亚胺能很好地溶解在常见有机溶剂中;玻璃化转变温度为191.2 °C;氮气气氛中,热失重10 %时的温度为473.8 °C,800 °C的残炭率为43 %;同时还有较好的力学性能,拉伸强度为98.5 MPa,拉伸模量为1.24 GPa,吸水率为0.67 %。     

Synthesis and properties of completely crystalline POM copolymers

Extended chain crystals of polyoxymethylene copolymers have been prepared by cationic copolymerization of trioxane and dioxolane. These crystals do not contain amorphous regions and behave like an ideal solid solution of CH₂CH₂O units in the crystal of CH₂O units up to a mole fraction of x_CH2CH₂O = 0.1. Melting points, melting enthalpies, specific heat, density and lattice parameters were measured as a function of mole fraction up to x_CH2CH₂O = 0.2. Comparison of the dependence of lattice parameters on mole fraction for the extended chain crystals and melt or solution crystallized copolymers indicates, that in the semi-crystalline samples the comonomer units are not distributed at random between amorphous and crystalline phase but the comonomer units are enriched in the amorphous phase.     

Synthesis and characterization of thiophene functionalized polystyrene copolymers and their electrochemical properties

Thiophene functionalized polystyrene samples (TFPS) were synthesized by atom transfer radical polymerization (ATRP) of styrene, followed by Suzuki coupling with 3‐thiophene (Th) boronic acid. Conducting graft polymer of TFPS with thiophene was achieved at 1.5 V in tetrabutylammonium tetrafluoroborate/dichloromethane (TBAFB/DM) by electrochemical methods. Spectroelectrochemical analysis of the resulting copolymers [P(TFPS‐co‐Th)] reflected electronic transitions at 449, 721 and 880 nm, revealing π ? π* transition, polaron and bipolaron band formation, respectively. We also successfully established the utilization of dual type complementary colored polymer electrochromic devices using P(TFPS‐co‐Th)/poly(3,4‐ethylenedioxythiophene (PEDOT) in sandwich configuration. The switching ability, stability and optical memory of the electrochromic device were investigated by UV–visible spectrophotometry and cyclic voltammetry. Device switches between brown and blue color with a switching time of 1.3 s were prepared with optical contrast (%ΔT) of 25 %. Copyright © 2005 Society of Chemical Industry     

Synthesis of amphiphilic copolymers having capability as emulsifiers and their surface chemical properties

Some comblike terpolymers composed of methyl methacrylate (MMA), methoxypolyethyleneglycol methacrylate (MPEGMA) as a hydrophilic component, and methoxypolypropyleneglycol methacrylate (MPPGMA) as a hydrophobic component were synthesized by both living radical photopolymerization and ordinary radical polymerization. Since these terpolymers showed a high surface activity, it was suggested that they could be utilized as good polymeric emulsifiers. The polymeric emulsions containing these emulsifiers also showed comparatively good emulsion and mechanical properties as an adhesive. From these facts, it was found that these terpolymers had almost the same emulsification capability as commercially available low molecular weight emulsifiers. Conversely, a difference in surface tension behavior of these terpolymers could be observed. We think that it was due to the chain arrangements (random or block sequence) of the terpolymer. Amphiphilic copolymer Emulsion polymerization Polymeric emulsifier Micelle formation     

Synthesis of acrylate modified vinyl chloride and vinyl isobutyl ether copolymers and their properties

With acrylic acid, butyl acrylate and methyl methacrylate as the monomers, acrylate modified vinyl chloride and vinyl isobutyl ether copolymers were prepared by solution polymerization. Firstly, vinyl chloride and vinyl isobutyl ether copolymers were grafted with acrylic monomers to obtain a product containing acrylate grafted vinyl chloride and vinyl isobutyl ether copolymers and polyacrylate, which was then neutralized by triethylamine and dispersed into water to get a self-emulsified emulsion. The acrylate modified vinyl chloride and vinyl isobutyl ether copolymers were characterized by Fourier transform infrared spectroscopy. The mean molecular weight of grafted polymer was determined by gel permeation chromatography, and the particle sizes and their distributions of the dispersions were measured by laser light scattering. The influences of initiator concentration, acrylate content, acrylic acid content and neutralization degree upon the properties of the modified copolymers were discussed. The results show that the emulsion will be with good storage stability, and the modified polymer will be with high water resistance, impact resistance and excellent adhesion when initiator concentration is 1.5%, acrylate content is 50%, acrylic acid content ranges from 9% to 11%, and neutralization degree is between 80% and 100%.     

Synthesis of amphiphilic graft copolymers of SBS with acrylamide and study of their properties

Graft copolymerization of SBS in the form of sodium ionomer with acrylamide in emulsion using benzoyl peroxide as initiator and sodium ionomer of maleated SBS as a self‐emulsifier, which can form a stable cyclohexane/water emulsion with AM without using any other emulsifier, was carried out. Factors affecting the graft copolymerization were studied. The grafting % can reach about 15%. Emulsifying properties of sodium ionomer of maleated SBS and the graft copolymer, as well as the compatibilizing effect of the graft copolymer in blending polyvinyl chloride (PVC) with SBS, were studied. The sodium ionomer of maleated SBS, the graft copolymers, and the blends were characterized with IR and DSC. The results showed that water absorbency and emulsifying volume increase obviously after graft copolymerization with AM. 0.2 g of the graft copolymer containing 14 wt % PAM grafts can emulsify a mixture of 30 mL toluene and 70 mL water completely. The graft copolymer can be used as an effective compatibilizer in the blending of PVC and SBS, more effective than the sodium ionomer of maleated SBS. Only 2 wt % of the copolymer based on the blend used in blending is enough to raise the tensile strength three times. The blends with weigh ratios of PVC/SBS at 3/7–4/6 in the presence of the graft copolymer behave as thermoplastic elastomers with a tensile strength of 14 MPa, an ultimate elongation of 750%, and a permanent set of 17%. Glass transition temperatures of the blend shifted inward in the presence of the graft copolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1248–1253, 2005     

Conducting copolymers of polytetrahydrofuran and their electrochromic properties

Living polytetrahydrofuran (PTHF) was terminated with sodium thiophene methonate to yield a polymer with a thiophene group at one end. Copolymerizations of PTHF with pyrrole and thiophene were achieved in water‐p‐toluene sulfonic acid and acetonitrile‐tetrabutylammonium tetrafluoroborate (TBAFB) solvent‐electrolyte couples via constant potential electrolyses. Characterizations of the samples were performed by NMR, cyclic voltammetry, FT‐IR, thermal analyses, and scanning electron microscopy. Electrical conductivities were measured by the four‐probe technique. PTHF/PTh film that was deposited on ITO‐glass in a dichloromethane‐TBAFB solvent‐electrolyte couple was found to exhibit electrochromic behavior and it electrochemically switches between blue oxidized and red reduced states. Optical analyses were carried out to investigate the electronic structure of PTHF/PTh electrochromic copolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1014–1023, 2005     

水性丙烯酸酯胶粘剂的合成及性能研究

甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸为单体,水为溶剂合成了聚丙烯酸酯粘合剂,用DSC、GPC等对产物进行了表征,研究了反应条件、原料配比及用量对产物性能的影响。     

苯乙烯-alt-马来酸酐共聚物的合成及其复鞣填充作用

采用溶液聚合的方法制备了系列相对分子质量(简称分子量,下同)不同的苯乙烯-alt-马来酸酐共聚物(SMA),并通过FTIR、1HNMR、13CNMR对产物结构进行了表征,通过DSC对其热性能进行了分析。考察了分子量大小对其在皮革中复鞣填充作用的影响。结果表明,分子量是影响SMA复鞣填充作用的重要因素,随聚合物分子量的增加,处理革的抗张强度降低、撕裂强度增加、部位差降低率增大。当SMA的Mn为6 620时,处理革的撕裂强度、抗张强度和部位差降低率分别为18.325 N/mm、9.519 N/mm2和7.44%,当SMA的Mn为59 058时,处理革的撕裂强度、抗张强度和部位差率降低率分别为20.577 N/mm、5.539 N/mm2和44.98%。     

Synthesis and application properties of fluorinated aromatic copolymers

Aromatic monomers with different fluorine concentrations and structural distribution patterns were synthesized. A series of copolymers based on methyl methacrylate, acrylate, and perfluorooctylalkyl acrylate were prepared by emulsion polymerization and were subsequently used as functional coatings to prepare water‐ and oil‐repellent cotton fabrics. The composition and structure of the outmost layer of the treated cotton surface were analyzed. A strong surface segregation of fluorinated segments was found for the treated samples, as shown by X‐ray photoelectron spectroscopy analysis. The basis for an in‐depth appreciation of the relationship between the molecular structure of the monomers and the properties of corresponding copolymer‐treated materials was provided (especially with regarding to their hydrophobic and oleophobic properties). The wetting characteristics of the fluorinated copolymers were found to be dependent on the density (number of side chains per constitutional repeat unit) and regularity of the fluorinated side chains. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4410–4418, 2013     

Synthesis and properties of novel conducting polyaniline copolymers

A novel copolymer based on aniline and N‐β‐cyanoethylaniline was chemically prepared and characterized by a number of techniques including UV–vis, FTIR, ESR, XRD, and TGA. According to the systematic studies on the physical properties, it was found that the copolymers had excellent solubility in common organic solvents especially in DMF and pyridine, while the conductivity and yield decreased as the content of cyanoethyl group increased in the system. Moreover, an increase in the feed ratio of N‐β‐cyanoethylaniline induced a blue‐shift of the absorption bands in the UV–vis and IR region and significant line broadening of ESR signals together with a reduction in spin density. The XRD patterns of the copolymers lost the characteristic diffraction peaks of emeraldine salt as the ratio of cyanoethyl group increased. The thermal stability of the copolymer was increased with increasing the feed molar ratio of N‐β‐cyanoethylaniline. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 140–147, 2007