聚2,6-萘二甲酸乙二酯的合成及固相聚合

采用生产 PET的工艺路线和设备生产聚 2 ,6 -萘二甲酸乙二酯 ( PEN)。讨论了酯化反应 ,熔融聚合 ,固相聚合阶段的工艺条件。通过固相聚合后 ,PEN切片的特性粘数可由熔融聚合的 0 .5 d L/g提高到 0 .7d L /g以上     

算图法测定聚合物的特性粘数

由外推法测定聚合物的特性粘数而求取聚合物分子量,是个相当普遍使用的方法。但此法测定特性粘数仍很耗时,为克服这一缺点,已提出了许多单点法来测定特性粘数值。本文应用算图法,从实验测定的特性粘数轨迹曲线,通过一个比浓粘度的测定,获得了聚环氧氯丙烷、聚氯乙烯、聚苯乙烯、聚甲基丙烯酸甲酯和聚对苯二甲酸酚酞酯等试样的特性粘数,并将所测得的结果与外推法及常用的Maron法Solomon—Ciuta法进行了比较。结果表明,采用算图法测定特性粘数,不但具有一般单点法所特有的快速、精确等优点,而且它的适用范围更广。     

表征聚氯乙烯分子量的各种指标的计算

本文汇编了以GB3401《聚氯乙烯树脂稀溶液粘数的测定》所得的相对粘度测定值计算表征聚氯乙烯分子量的粘数、K值、特性粘数、平均聚合度、绝对粘度等指标的计算式,供参考。     

高粘聚酯切片特性粘数测试方法的优化

针对高粘PET样品的特性,通过试验对比,对聚酯特性粘数分析测试方法中规定的样品粉碎时间及称样量进行了优化,得到了适用于高粘PET样品特性粘数测试的最佳测试条件。     

“水包水”聚合物乳液特性粘数测定方法的研究

本文采用两种方法,一种是采用沉淀再溶解法配制聚丙烯酰胺"水包水"乳液的水溶液,采用乌氏粘度计用五点稀释法来测定聚丙烯酰胺"水包水"乳液的特性粘数[η];另一种是以第一种方法得出的结果为标准试验并总结出的一套既简便误差又不大的测定聚丙烯酰胺"水包水"乳液特性粘数的方法,即用直接稀释乳液法配制聚丙烯酰胺"水包水"乳液的水溶液,采用乌氏粘度计用一点法来测定聚丙烯酰胺"水包水"乳液的特性粘数[η]。通过对一系列的阳离子型"水包水"聚丙烯酰胺乳液在每隔一段时间内测定其特性粘数的变化趋势,得出了"水包水"聚丙烯酰胺乳液的稳定性的有关信息:乳液的特性粘数[η]先随时间的增加而急剧下降,然后下降幅度又趋于平缓,最后达到一个稳定值。     

聚天冬氨酸稀溶液的粘度特性表征

对聚天冬氨酸(PASP)稀溶液的粘度特性进行了考察,测定了30℃条件下,聚天冬氨酸在纯水溶液及NaCl水溶液中的特性粘数,考察了在不同离子强度情况下,PASP稀溶液的特性粘数的变化;同时又根据杨海洋等提出的粘度法研究高分子溶液行为的实验改进(Ⅱ)对实验进行了改进,测出了PASP在NaCl水溶液中的特性粘数[η]。     

聚醚醚酮分子量对熔体粘度的影响

本文通过对聚醚醚酮(PEEK)熔体粘度及溶液特性粘数的测定,描述了PEEK在零切变速率下的熔体粘度(η。)与特生粘数[η]之间的关系,建立了关系方程η。=A[η]~β。给出了适合于作复合材料基体的PEEK的特性粘数范围。     

《聚甲醛树脂稀溶液粘数和特性粘数测定》等两项行业标准修订介绍

《聚甲醛树脂稀溶液粘数和特性粘数测定》和《聚氯醚树脂稀溶液粘数和特性粘数测定》两项国家标准经清理整顿后调整为行业标准。该两项行业标准经化工部晨光化工研究院（成都）负责起草修订,于１９９７年１２月完成报批。现将两项标准简介如下。１标准制定的依据和意义合成树脂的粘度是直接反映工艺过程和材料性能的参数。因此,在产品开发和产品生产质量控制上都把粘度作为必测指标。ＧＢ１８４６－８０和ＧＢ１８４７－８０由上海合成树脂研究所组织起草。自发布以来,规范了聚氨酸和聚甲醛树脂稀溶液粘度的测试条件,被科研和生产实践所…     

高聚物特性粘数的研究 Ⅰ特性粘数的二次外推

高聚物分子量的测定,最方便、应用最广泛的方法是粘度法。即高聚物溶解在一定的溶剂中,在一定的温度下测得其特性粘数,然后按已经订出的分子量—特性粘数关系式。 [η]=KM~α求得聚合物的分子量。但是,对于特性粘数的概念,以及如何正确求得聚合物的特性     

聚乙烯醇聚合度测定中极限粘数测定方法探讨

通过试验,探讨了GB12010．9—89标准《聚乙烯醇树脂平均聚合度测定方法》中极限粘数测定存在的问题,指出聚乙烯醇平均聚合度测定中极限粘数的测定必须先测定哈金斯相互作用参数后H值,根据尼。值大小决定采用哪种测定方式和何种计算公式计算极限粘数[η]。当kH等于1／3时,可采用一点法测定并计算极限粘数[η],当kH不等于1／3时,必须测定多个点的粘度采用ηsp／C—c曲线回归拟合外推至零浓度得到极限粘数[η]。并对测定用粘度计的选择作了分析。     

Morphology and barrier mechanism of biaxially oriented poly(ethylene terephthalate)/poly(ethylene 2,6‐naphthalate) blends

To improve the barrier properties of poly(ethylene terephthalate) (PET), PET/poly(ethylene 2,6‐naphthalate) (PEN) blends with different concentrations of PEN were prepared and were then processed into biaxially oriented PET/PEN films. The air permeability of bioriented films of pure PET, pure PEN, and PET/PEN blends were tested by the differential pressure method. The morphology of the blends was studied by scanning electron microscopy (SEM) observation of the impact fracture surfaces of extruded PET/PEN samples, and the morphology of the films was also investigated by SEM. The results of the study indicated that PEN could effectively improve the barrier properties of PET, and the barrier properties of the PET/PEN blends improved with increasing PEN concentration. When the PEN concentration was equal to or less than 30%, as in this study, the PET/PEN blends were phase‐separated; that is, PET formed the continuous phase, whereas PEN formed a dispersed phase of particles, and the interface was firmly integrated because of transesterification. After the PET/PEN blends were bioriented, the PET matrix contained a PEN microstructure consisting of parallel and extended, separate layers. This multilayer microstructure was characterized by microcontinuity, which resulted in improved barrier properties because air permeation was delayed as the air had to detour around the PEN layer structure. At a constant PEN concentration, the more extended the PEN layers were, the better the barrier properties were of the PET/PEN blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1309–1316, 2006     

聚芳醚腈连续纤维增强复合材料制备与性能研究

以双酚A型聚芳醚腈(PEN)为基体树脂,采用预浸渍工艺(溶液预渍工艺)和后浸渍工艺(薄膜叠层法)相结合的方法制备了PEN连续纤维增强复合材料;并研究了以ZnCl2为催化剂在热处理前后PEN复合材料性能的变化。研究结果表明:PEN连续纤维增强复合材料具有很高的力学强度和热稳定性,复合材料经热处理后由于PEN树脂侧链腈基产生交联反应,力学强度和热稳定性得到大幅提高。     

Effect of modified carbon nanotube on the properties of aromatic polyester nanocomposites

Aromatic polyester nanocomposites based on poly(ethylene 2,6-naphthalate) (PEN) and carbon nanotube (CNT) were prepared by melt blending using a twin-screw extruder. Modification of CNT to introduce carboxylic acid groups on the surface was performed to enhance intermolecular interactions between CNT and the PEN matrix through hydrogen bonding formation. Morphological observations revealed that the modified CNT was uniformly dispersed in the PEN matrix and increased interfacial adhesion between the nanotubes and the PEN, as compared to the untreated CNT. Furthermore, a very small quantity of the modified CNT substantially improved thermal stability and tensile strength/modulus of the PEN nanocomposites. This study demonstrates that the thermal, mechanical, and rheological properties of the PEN nanocomposites are strongly dependent on the uniform dispersion of CNT and the interactions between CNT and PEN, which can be enhanced by slight chemical modification of CNT, providing a design guide of CNT-reinforced PEN nanocomposites with a great potential for industrial uses.     

PEN聚酯工艺的研究进展

介绍了聚萘二甲酸乙二醇酯(PEN)聚酯的性能和用途，详细概括了合成PEN聚酯的各种工艺路线研究进展情况。     

Morphology,thermal and mechanical properties of glass fiber‐reinforced crosslinkable poly(arylene ether nitrile)

Crosslinkable poly(arylene ether nitrile)/glass fiber (PEN/GF) composites with high thermal stabilities and mechanical properties were prepared by a economically and environmentally viable method of melt extrusion and injection molding. The feasibility of using PEN/GF composites was investigated by evaluating its morphological, rheological, thermal, and mechanical properties. The morphology shows a good dispersion and strong interfacial interaction between PEN and GF. Thermal studies reveal that the thermal stabilities of PEN/GF are improved significantly with increase of GF content. Mechanical investigation manifested that GFs have strengthening effect (increase in flexural, tensile, and impact strength) on the mechanical performance of PEN composites. Most importantly, crosslinking reaction of PEN/GF composites can further improve their mechanical performances, because a couple of GFs are agglomerated by thermal motion and strong interfacial adhesion and the local agglomeration does not break the global uniform distribution. This work shows that both the enhancement of GF content and the crosslinking reaction of PEN/GF composites are two key factors influencing the thermal and mechanical properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

New concept of reducing a birefringence of poly(ethylene naphthalate) by a novel alloy with fluorene‐based polyester

This study proposes the new concept of reducing the birefringence of poly(ethylene naphthalate) (PEN) by a novel alloy with fluorene‐based polyester (FBP) involving the “cardo” structure in it. The alloys composed of PEN and FBP were prepared by simple melt blending method (process A) and reactive melt blending (process B). The resulting alloys were characterized by DSC, XRD, DMA, tensile testing, and polarized light microscopy. All PEN‐FBP alloys showed transparency and a single glass transition temperature (T_g), indicating that PEN‐FBP alloys were completely compatible. It was also demonstrated that T_g for PEN was shifted to the high‐temperature side by alloying with FBP. A large amount of the orientation‐induced birefringence was induced in drawn PEN sheets; however, in the cases of PEN‐FBP alloys, it was drastically decreased because of alloying with FBP. We could reveal the new concept for “low‐orientation‐induced birefringence material.” POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Synergetic effect of cyanogen functionalized carbon nanotube and graphene on the mechanical and thermal properties of poly (arylene ether nitrile)

Cyanogen functionalized carbon nanotube and graphene/poly (arylene ether nitrile) (CNT-CN/GN-CN/PEN) nanocomposite films were prepared by a facile solution casting method. The weight ratio of CNT-CN/GN-CN was varied from CNT-dominated to GN-dominated for the purpose of investigating their synergetic effects on the mechanical and thermal properties of PEN nanocomposites. Consequently, GN-CN/PEN composites demonstrated better mechanical and thermal properties than CNT-CN/PEN composites due to larger contact area between GN-CN and PEN matrix. Nevertheless, all CNT-CN/GN-CN/PEN composites exhibit enhanced mechanical properties than those of GN-only nanocomposites. With the increasing of CNT-CN/GN-CN weight ratio, the mechanical properties of CNT-CN/GN-CN/PEN composites increase, then decrease, and reach their maximums when CNT-CN/GN-CN weight ratio is around 4/4. From scanning electron microscope images, it is found that around that point GN-CN is flatly dispersed and CNT-CN is penetrated into GN-CN, capable of transferring stress load and thus decreasing interface loss. Thermal properties of CNT-CN/GN-CN/PEN composites once again confirmed the joint effect of CNT-CN and GN-CN, leading to improved thermal properties. In short, a synergistic effect between one-dimensional (1-D) CNT and two-dimensional (2-D) GN on the mechanical and thermal properties of nanocomposites have been demonstrated in these systems.     

Effect of nitrile functionalized graphene on the properties of poly(arylene ether nitrile) nanocomposites

In this study, novel nitrile functionalized graphene (GN‐nitrile)/poly(arylene ether nitrile) (PEN) nanocomposites were prepared by an easy solution‐casting method and investigated for the effect of surface modification on the dielectric, mechanical and thermal properties. Graphene (GN) was first functionalized by introduction of nitrile groups onto the GN plane, which was confirmed by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, thermogravimetric analysis and dispersibility research. Compared with pure GN, the grafted nitrile groups on the GN‐nitrile can interact with nitrile groups in PEN and lead to flat but better dispersion and stronger adhesion in/to the PEN matrix. Consequently, GN‐nitrile had a more significant enhancement effect on the properties of PEN. The dielectric constant of the PEN/GN‐nitrile nanocomposite with 5 wt% GN‐nitrile reaches 11.5 at 100 Hz, which is much larger than that of the pure PEN matrix (3.1). Meanwhile, dielectric loss is quite small and stable and the dielectric properties showed little frequency dependence. For 5 wt% GN‐nitrile reinforced PEN composites, increases of 17.6% in tensile strength, 26.4% in tensile modulus and 21 °C in T_d5% were obtained. All PEN/GN‐nitrile nanocomposite films can stand high temperature, up to 480 °C. Hence, novel dielectric PEN/GN‐nitrile nanocomposite films with excellent mechanical and thermal properties can be used as dielectric materials under some critical circumstances such as high wear and temperature. Copyright © 2012 Society of Chemical Industry     

Influence of viscosity ratio on processing and morphology of thermotropic liquid crystal polymer‐reinforced poly(ethylene 2,6‐naphthalate) blends

Thermotropic liquid crystal polymer (TLCP) microfibril‐reinforced poly(ethylene 2,6‐naphthalate) (PEN) composites with various intrinsic viscosities were prepared by a melt compounding method. Polymer composites consisting of bulk cheap polyester with a small amount of expensive TLCP are of interest from a commercial perspective. The TLCP acts as a nucleating agent in the TLCP/PEN composites, enhancing the crystallization of the PEN matrix through heterogeneous nucleation. The structural viscosity index of the TLCP/PEN composites was lower than that of PEN and TLCP, which was attributed to the formation of TLCP fibrillar structures with elongated fibrils in the PEN matrix. The TLCP/PEN composites with higher intrinsic viscosity than the polymer matrix contained these elongated fibrils, and had a TLCP component with a smaller average diameter, and a narrower diameter distribution than TLCP/PEN composites with lower intrinsic viscosity. The higher intrinsic viscosity of the polymer matrix, the higher shear rate and the lower viscosity ratio of TLCP to PEN can all favour TLCP fibrillation in the polymer composites. Copyright © 2006 Society of Chemical Industry     

聚萘二甲酸乙二醇酯的市场现状及发展前景

简述了聚萘二甲酸乙二醇酯(PEN)的优异性能,诸如高耐热性,良好的机械性能,阻气性和防紫外线性等等;介绍了PEN在薄膜、啤酒瓶、纤维等领域的应用情况;指出了萘二甲酸(NDA)和二甲基萘(DMN)的工业化,大大降低了PEN成本,为PEN的快速发展创造了条件。