氮杂环高性能树脂研究进展

含有全芳环扭曲、非平面结构氮杂环高性能树脂兼具耐高温可溶解特性,综合性能优异,解决了传统高性能工程塑料不能兼具耐高温可溶解的技术难题,加工方式多样,应用领域广泛。总结出"全芳环非共平面扭曲的分子链结构可赋予聚合物既耐高温又可溶解的优异综合性能"的分子设计思想。研制成功含二氮杂萘酮联苯结构的新型聚芳醚砜、聚芳醚酮、聚芳醚腈、聚芳酰胺、聚苯并咪唑、聚(1,3,5-三芳基均三嗪)等系列高性能树脂。本文将重点介绍含二氮杂萘酮结构聚(1,3,5-三芳基均三嗪)、聚苯并咪唑以及可注射成型四元共聚芳醚砜酮等合成、结构与性能,以及其应用技术的研究开发最新进展。     

新型杂环氯代聚芳醚的合成与性能

以自制的新型氯代类双酚化合物4-(3-氯-4-羟基苯基）-2,3-二氮杂萘-1-酮（OC-HPPZ）为单体,分别与4,4/-二氟二苯酮、4,4/-二氯二苯砚和1,4-双-（4-氯代苯甲酰基）苯进行缩聚反应,合成了一类新型的具有较高分子质量的聚芳醚材料。利用FTIR、1H NMR等分析手段研究了类双酚化合物OC-HPPZ及其聚合物的结构;采用差示扫描量热仪（DSC）、热重分析仪（TGA）研究了聚合物的耐热性能,结果表明,新型聚芳醚砜、聚芳醚酮和聚芳醚酮酮具有优异的耐热性能和热稳定性能,其玻璃化转变温度为234～287℃,在氮气氛中5%热失重温度均高于420℃,新型氯代聚芳醚在氯仿、N、N-二甲基乙酰胺等极性有机溶剂中可溶解并浇铸得到透明、韧性的薄膜。     

从工程塑料到超工程塑料

简要介绍重要工程塑料的优缺点,着重讨论聚芳醚、聚芳酮、聚芳砜、聚芳酯及液晶类聚合物、聚芳酰胺以及聚酰亚胺类等主要超工程塑料的合成、性能及发展趋势,指出PPS及PEEK是特别值得密切注意的两个品种。     

聚芳醚砜醚酮共聚物的合成与表征

通过低温溶液亲电共缩聚合成了聚芳醚醚酮醚砜醚酮(Ia)、聚芳醚酮酮醚砜醚酮(Ib),甲基取代、双邻位甲基取代的聚芳醚酮酮醚酮醚砜醚酮(Ic、Id)等4种结构新型的共聚物。用傅里叶红外光谱仪(FT-IR)、核磁共振(1H-NMR)、差示扫描量热仪(DSC)、热重分析(TGA)、X射线衍射仪(WAXD)对聚合物进行了结构表征和性能测试。结果表明,共聚物有较高的玻璃化转变温度(Tg)177℃~188℃;较高的热分解温度(Td5%≥460℃),共聚物能溶解于N-甲基-2-吡咯烷酮,四氯乙烷和浓硫酸中;甲基取代的共聚物溶解性得到了明显改善,室温下还能溶于二氯甲烷、二氯乙烷、氯仿、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺中。     

聚芳醚砜改性研究的进展

本文综述了近年来聚芳醚砜改性研究的进展，着重介绍了氰酸根、氨基、乙炔基、乙烯基、丙烯基、烯丙基、环氧基、马来酰亚胺基，以及氰基等活性基团作为封端基或侧基的聚芳醚砜的合成及应用。     

多嵌段磺化聚醚砜质子交换膜材料的制备及性能研究

制备出一系列磺化度为44.6%、49.7%和54.4%的磺化-非磺化四嵌段聚芳醚砜材料,并将其用于直接甲醇燃料电池的质子交换膜.这种四嵌段聚芳醚砜薄膜具有互穿网络微观结构,亲-疏水相分离尺度较小.与具有类似结构的两嵌段聚芳醚砜相比,其质子传导相关性能更为优异.随温度和磺化度升高,所制备的质子交换膜的吸水率、甲醇透过率、离子交换容量和质子传导率均有所升高.当温度为90℃,磺化度为54.4%时,相应薄膜的质子传导率较高,为9.38mS/cm,且甲醇透过率依然较低,仅为3.80×10-8 L/m·s.     

含二氮杂萘酮联苯结构高性能工程塑料研究进展

介绍了含二氮杂萘酮联苯结构聚芳醚砜酮、聚芳醚腈砜酮以及同时还含芳基均三嗪环结构聚芳醚三大系列新型高性能工程塑料的合成与性能及其在高性能树脂基复合材料、绝缘漆、漆包线、功能涂料以及耐高温功能膜等领域的研究进展。从分子结构设计出发,研制成功具有扭曲、非平面结构特点的含二氮杂萘酮联苯结构新型单体,进而与双卤单体经亲核取代逐步聚合反应合成了多系列含二氮杂萘酮联苯结构新型聚芳醚类高性能工程塑料,既耐高温又可溶解,解决了传统高性能工程塑料不能兼具耐高温可溶解的技术难题。其玻璃化转变温度达250～375℃,5%热失重起始温度均高于500℃;可溶解于N-甲基吡咯烷酮、N,N-二甲基乙酰胺以及氯仿等几种有机溶剂;综合性能优异,尤其是在高温下依然保持优异的综合性能;可多种方式加工,不仅可采用模压、挤出、注射等热成型加工,还可采用溶液方式加工应用;广泛应用于航空航天、核能、电子电气等高技术领域和国民经济众多行业部门。     

甲基取代杂萘联苯型聚芳醚的合成、表征及性能

以自制的新型甲基取代类双酚 4 - ( 3-甲基 - 4 -羟基苯基 ) - 2 - 3-二氮杂萘 - 1-酮 ( OM- HPPZ)为单体与4 ,4′-二氟二苯酮、4 ,4′-二氯二苯砜进行亲核缩聚反应 ,制得了一类新型甲基取代聚芳醚酮、聚芳醚砜及其共聚物聚芳醚砜酮树脂。在适宜的聚合条件下 ,获得了高分子量的聚合物 ,聚醚酮的特性粘度可达0 .70× 10 2 m L/ g;通过调节砜酮比例 ( S/ K)可获得不同分子量、不同玻璃化温度的共聚物 ( PPESK)。利用 DSC、TGA研究了聚合物的耐热性能 ,结果表明 ,新型聚芳醚玻璃化温度高 ( 2 5 2℃～ 2 90℃ ) ,耐热稳定性好 ( 5 %热失重温度高于 4 16℃ ) ,在氯仿、DMAc等极性有机溶剂中可溶解成膜 ,以 FT- IR和 1H-NMR研究了类双酚单体 OM- HPPZ和聚合物的结构 ,证明与设计结构完全一致     

侧链含蒽可光交联聚芳醚酮的制备与表征

聚芳醚酮是一种具有高热稳定性、优异的机械性能和化学稳定性的特殊材料。但是,商品化的聚芳醚酮热塑性塑料由于其高的玻璃化转变温度和不溶性而难以加工。聚芳醚酮的应用由于自身的缺点而受到限制。因此,制备具有良好加工性能并且可以保持良好热稳定性的聚芳醚酮是关键的一步。合成了一系列具有不同蒽含量的光交联聚芳醚酮。该光交联过程是基于蒽环进行[4+4]-环加成反应,由365 nm紫外光引发且不需要光引发剂的。这个过程非常迅速和方便。所制备的聚芳醚酮是一种低分子量前体聚合物,具有较低的玻璃化转变温度和良好的溶解性。因此,聚合物很容易被加工。加工成型后利用紫外光引发光交联反应形成网状聚合物。通过DSC和TGA分析,与未交联聚合物相比,交联后的聚芳醚酮表现出良好的热稳定性,其玻璃化温度和热分解温度明显升高。     

含叔丁基新型聚芳醚砜薄膜的制备及性能研究

以双酚A(BPA)、叔丁基对苯二酚(TBHQ)、4,4'-二氯二苯砜(DCDS)为共聚单元,在分子主链侧基中引入大体积疏水性的叔丁基,通过调整BPA与DCDS的比例制备了系列聚芳醚砜薄膜,并对薄膜进行了红外表征和性能测试.结果 表明:系列薄膜综合性能优异,介电常数(1MHz,2.76～3.05)、介电损耗(＜0.75％...     

界面聚合法合成苯胺与邻甲氧基苯胺的樟脑磺酸掺杂共聚物及其表征

采用界面聚合法在樟脑磺酸存在的状态下合成了聚苯胺、聚邻甲氧基苯胺以及苯胺与邻甲氧基苯胺的共聚物.利用红外光谱,紫外可见吸收光谱,电子扫描微电镜,X-射线粉末衍射,循环伏安,电导率测试等手段对聚合物进行了表征,初步探讨了单体配比对共聚物形貌、结构及性能的影响.结果表明,界面聚合法合成的上述各聚合物均呈现微米级颗粒状分布,颗粒直径大多在100nm以内;共聚后聚合物的结晶性能下降;循环伏安及电导率测试结果表明,随着聚合物主链中邻甲氧基苯胺结构单元的增加,聚合物的电化学活性及电导率呈下降趋势.     

Synthesis and characterization of chiral main chain polyesters with polar segments tailored for second harmonic generation

The synthesis, characterization and solvatochromic behavior of a new series of chiral polyesters are reported. These polymers with -conjugated donor-acceptor segments were synthesized with a view to be suitable for second harmonic generation. The polyesters were prepared by the reaction of diacid chlorides with biphenolic azo chromophores with -conformation and optically active dihydroxy compound (isosorbide). The polymers containing isosorbide units are optically active. They showed T _g between 100°C to 160°C and are stable up to 400°C. A red shift in the longer wavelength absorption band of these polymers in UV-Vis. absorption spectra (positive solvatochromism) shows that the dipole moment of excited state is higher than that of the ground state. Therefore these polyesters are expected to have good second harmonic generation capability.     

具有光学性能的含芴聚亚胺酮的合成与表征

以含芴芳香二胺和2,7-二溴-9-芴酮为单体,通过Buchwald-Hartwig交叉偶联反应缩聚合成了含芴聚亚胺酮(PIKF)。聚合物结构经核磁共振(1H-NMR)、红外光谱(FT-IR)及元素分析得以确认。通过凝胶渗透色谱(GPC)、差示扫描量热分析(DSC)、热重分析(TG)和X射线衍射(XRD)等对其性能进行测试,结果表明该类聚合物具有较高的分子量(-Mw>3.0×104)以及良好的热稳定性(T5%>310℃),在40℃～350℃的范围内没有观测到玻璃化转变;XRD显示PIKF为无定型结构,因而具有良好的溶解性能。另外,利用紫外、荧光等对其光学性能进行了测试,在四氢呋喃(THF)中的UV-vis的最大吸收波长为271 nm和369 nm左右,最大荧光发射波长分别在445 nm和455 nm。     

纳米级聚噻吩衍生物的固相聚合

首次采用固相聚合法在室温条件下制备了聚(3,6-二噻基-哒嗪)[P(DThPD)],聚(1,4-二噻基-苯)[P(DThPh)]和聚(4,7-二噻基-2,1,3-苯并噻二唑)[P(DThB)].并用红外光谱、紫外-可见光光谱、荧光光谱、电子扫描显微镜、电子透射显微镜、循环伏安(cyclic voltammogram)等测试方法,对聚合物进行表征.结果表明,固相聚合法合成的P(DThPD)和P(DThPh)具有纳米颗粒串连的棒状或环状结构;P(DThPD)分别在336 nm、450nm和580nm(w)处有吸收峰;P(DThPh)分别在325nm和410nm处有吸收峰;P(DThB)分别在460nm、550nm和700nm处有吸收峰.P(DThPh)和P(DThB)分别在488nm和599nm处有较强的荧光.循环伏安测试表明,固相聚合法合成的3种聚合物均具有较好的电化学活性.     

Effect of the side chain length on the optical and electrical properties of soluble PPV derivatives

2-Alkoxy-5-methoxy poly(1,4-phenylenevinylene) derivatives with different lengths of the alkoxy side chain have been synthesized via a modified Gilch polymerization. Their number-average molecular weights are in the range of 10,000–14,000. ¹H NMR, ¹³C NMR, FT-IR spectroscopies have shown that the polymer structures are the expected ones and were free from defects. The polymers are amorphous and show good thermal stability up to 300 °C. The optical absorption band of MB-PPV, MH-PPV, MO-PPV and MDD-PPV thin films are at 496 nm, 496 nm, 494 nm and 507 nm, respectively. Photoluminescence emission maxima of the above polymers appear at 624 nm, 582 nm, 629 nm and 578 nm, respectively. A composite photoluminescence response is observed at the exception of MO-PPV showing a single PL maximum. Light-emitting diodes (LEDs) based on these polymers were fabricated and characterized by current–voltage measurements. The comparison of the optical and electrical properties of these different polymers showed a small influence of the length of the side alkoxy chain and/or to the length of the main polymeric chain.     

表面活性剂PEG400存在下硫化铜和氧化亚铜纳米材料的热分解合成

本文报道了在表面活性剂PEG400存在下通过简单的热分解反应分别合成了硫化铜纳米粒子和氧化亚铜纳米方块,硫化铜纳米粒子直径在11~20nm之间,氧化亚铜纳米方块尺寸在300~800nm之间。用X射线衍射仪(XRD)和透射电子显微镜(TEM))对产物的结构和形貌进行了表征。同时,对产物的紫外—可见光吸收性能(UV-vis)作了测试,结果表明,硫化铜纳米粒子在430nm处有一个较为明显的肩峰,氧化亚铜纳米方块在400nm处有较为明显的吸收峰,两种材料与其本体相比均发生了蓝移。     

苝酰亚胺类化合物的功能改性及光谱性能研究

本文合成了三种含有羧基的苝酰亚胺化合物，并研究了其紫外-可见吸收光谱及荧光光谱的特征；研究表明，苝环上1，6，7，12位取代基的引入，使得所合成的苝酰亚胺类化合物的最大吸收波长分别红移了50nm、49nm；Stokes位移变大30、31nm。而荧光量子产率的下降，但不是很明显。     

Quantum confinement effects in Gd-doped CdS nanoparticles prepared by chemical precipitation technique

CdS and Gd-doped CdS nanoparticles have been synthesized by chemical precipitation technique. The X-ray diffraction patterns show that the CdS and Gd-doped CdS nanoparticles exhibit hexagonal structure. The high resolution transmission electron microscope image shows that CdS and Gd-doped CdS nanoparticles have particle size lying in the range of 3.5 to 4.0 nm. Raman spectra show that 1LO, 2LO and 3LO peaks of the Gd-doped CdS nanoparticles are slightly shifted to lower wavenumber side when compared to that of CdS. Optical absorption spectra of Gd-doped CdS nanoparticles shows that absorption edge is slightly shifted towards longer wavelength side (red shift) when compared to that of CdS and this shift is due to the quantum confinement effect present in the samples.     

Soluble PPVs with few structural defects: Synthesis and characterization

A series of 2,5-dialkoxy poly(1,4-phenylenevinylene) derivatives with different alkoxy side-chain lengths were synthesized via a modified Gilch polymerization. Prolonged reaction and additional base treatment at elevated temperature lead to PPVs with very low chlorine content and few structural defects. The polymers were synthesized in satisfactory yields (45–65%) and had number-average molecular weights of 10,000–14,000. Structural characterization was accomplished by FT-IR, ¹H-NMR, ¹³C-NMR spectroscopy and by elemental analysis. All polymers are amorphous, stable up to 300 °C and soluble in both chloroform and tetrahydrofuran. The UV-Vis absorption and emission in the solid state are in the range 496–507 nm and 578–629 nm, respectively. Band gaps calculated from the UV-Vis spectra edge are in the range 2.06–2.11 eV. Light-emitting diodes (LEDs) based on these polymers were fabricated and characterized by current–voltage measurements.     

Annealing of ZnS nanocrystals grown by colloidal synthesis

ZnS nanocrystals (NCs) capped with tetramethylammonium (TMAH) were synthesized from ZnCl₂ · 2H₂O and thiourea using a wet chemical process. Further treatments of the nanocrystals such as aging, and annealing have been conducted to examine the stability of the grown samples. The X-ray diffraction spectra show that the crystal has a zinc blende structure with particle size of about 2 nm. The evidence of nanocrystalline character is also clear in the UV–Vis absorption that shows an excitonic peak at about 236 nm (5.2 eV) arising from band edge transitions. A photoluminescence emission peak centered at about 450 nm (2.7 eV) is attributed to transitions between shallow donors and Zn⁺ vacancies. Both absorption and photoluminescence spectra show that sample aging does not affect the characteristics of the sample, possibly due to protection by TMAH capping. Annealing at 700 °C and 900 °C results in the red shift of the photoluminescence.