聚(丁二酸乙二酯-共-对苯二甲酸乙二酯)的流变性能

以对苯二甲酸、丁二酸和乙二醇为单体合成了3组不同特性黏度的聚(丁二酸乙二酯-共-对苯二甲酸乙二酯) (PEST),采用毛细管流变仪重点研究了样品的流变性能.结果表明:共聚酯PEST是假塑性流体,呈现典型的切力变稀现象;随着剪切速率增大,黏流活化能降低;非牛顿指数随着特性黏度的增大而减小,随温度的升高而增大;结构黏度指数随着温度升高而降低,随特性黏度的增大而逐渐增加.流变性能的研究结果对PEST共聚酯的加工生产提供了一定参考.     

聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯的热降解动力学

在高纯氮气保护下,采用不同的升温速率,用热失重法对聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯(PBST)共聚酯的热降解行为和热降解动力学进行了研究。用Kissinger、Flynn-Wall-Ozawa及Friedman 3种方法对比计算了PBST共聚酯在氮气气氛中的热降解活化能,并对PBST共聚酯的热老化寿命进行了探讨。结果表明在氮气气氛中共聚酯的热稳定性随BT含量增加而增强,不同组分的PBST共聚酯热降解均为1级反应,分解活化能E均随BT摩尔分数的增加而增大。     

聚对苯二甲酸-共-丁二酸丁二醇酯的研究及产业化现状

介绍了生物可降解材料脂肪族/芳香族共聚酯聚对苯二甲酸-共-丁二酸丁二醇酯(PBST)的合成工艺技术及基本性能,综述了近年来国内外PBST的研究现状和产业化现状.PBST的合成工艺主要是酯交换法和直接酯化法,酯交换法原料成本高、副产物分离较难、合成的PBST相对分子质量低;直接酯化法可以得到纯度较高的PBST,副产物只有...     

聚对苯二甲酸丁二酯结构与性能研究进展

综述了关于聚对苯二甲酸丁二酯结构与性能研究的一些结果，以及这些结果对理论和其应用的意义。同时．简介了如何结合其结构和性能进行改性．开拓应用等问题。     

扩链改性聚对苯二甲酸丁二醇酯流变性能的研究

利用毛细管流变仪和转矩流变仪对扩链改性聚对苯二甲酸丁二醇酯(PBT)的流变性能进行了研究，讨论了扩链剂用量对熔体流变性能的影响。结果表明：PBT经扩链改性后熔体的扭矩有显著的提高，在相同剪切速率下，其动态粘度比空白样增加了2～4倍，说明扩链剂对其有明显的扩链效果；其流动特性更趋于非牛顿型流体。     

支化改性对聚丁二酸丁二醇酯性能影响

采用直接熔融缩聚法,用丁二酸和丁二醇分别与1,2-丙二醇、1,2-戊二醇、1,2-己二醇共聚改性合成得到一系列产物聚丁二酸丁二醇酯(PBS)、聚(丁二酸丁二醇酯-co-丁二酸1,2-丙二醇酯)(PBSP)、聚(丁二酸丁二醇酯-co-丁二酸1,2-戊二醇酯)(PBST)和聚(丁二酸丁二醇酯-co-丁二酸1,2-己二醇酯)(PBSH).利用乌氏黏度计、1H NMR、DSC等对其摩尔质量、化学结构、热学性能和力学性能进行表征.结果表明,随着共聚酯分子主链上支链长度的增加,数均摩尔质量(Mn)几乎无变化,对应的熔点(Tm)、结晶温度(Te)、结晶度(Xc)、弯曲强度和拉伸强度逐渐降低,断裂伸长率明显增加.冲击强度变化:PBSP-10＜ PBST-10＜ PBSH-10＜PBS,总体上PBSH-10表现出良好的综合力学性能.     

聚己二酸丁二醇-co-聚对苯二甲酸丁二醇酯扩链改性研究

为了降低聚己二酸丁二醇-co-聚对苯二甲酸丁二醇酯(PBAT)的熔融指数,在双螺杆中,利用多元环氧扩链剂(ADR)对PBAT进行了扩链反应.基于正交实验对ADR扩链PBAT反应进行了研究,确定了影响反应的主要因素,并对扩链后的树脂进行了流变以及常规性能研究.结果 表明,扩链剂浓度对扩链反应速率影响最大,反应温度次之.A...     

聚对苯二甲酸丁二醇酯的发展现状

综述了聚对苯二甲酸丁二醇酯(PBT)在不同领域的应用、在国内外市场的占有率以及PBT的改性技术和发展前景。     

过滤材料用熔喷聚对苯二甲酸丁二醇酯切片的性能研究

通过对Ticona公司的聚对苯二甲酸丁二醇酯(PBT)切片性能的测试,分析了其热性能、结晶性能以及流变性能。实验结果表明:该种熔喷专用PBT切片熔点为224.7℃,分解温度为382.3℃;随着降温速率的增大,体系结晶峰值温度降低,结晶速率加快;随着体系温度的升高,PBT熔体非牛顿指数增大,体系流动性增强,易于熔喷纺丝。     

PBT共混改性研究最新进展

综述了最近几年国内外聚对苯二甲酸丁二醇酯(PBT)共混改性的研究进展,分类介绍PBT/聚烯烃、PBT/同系聚酯、PBT/液晶、PBT/弹性体、PBT/聚碳酸酯等不同共混体系,讨论了各体系中的相行为、相容性、热稳定性、力学性能等,并对该类共混物的发展趋势作了简要的分析。     

Blends of poly(ethylene terephthalate) and poly(butylene terephthalate)

Commercial grade poly(ethylene terephthalate), (PET, intrinsic viscosity = 0.80 dL/g) and poly(butylene terephthalate), (PBT, intrinsic viscosity = 1.00 dL/g) were melt blended over the entire composition range using a counterrotating twin‐screw extruder. The mechanical, thermal, electrical, and rheological properties of the blends were studied. All of the blends showed higher impact properties than that of PET or PBT. The 50:50 blend composition exhibited the highest impact value. Other mechanical properties also showed similar trends for blends of this composition. The addition of PBT increased the processability of PET. Differential scanning calorimetry data showed the presence of both phases. For all blends, only a single glass‐transition temperature was observed. The melting characteristics of one phase were influenced by the presence of the other. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 75–82, 2005     

Partially Bio-Based Polyester Bead Foams via Extrusion Foaming of Poly(butylene terephthalate)/Poly(butylene furanoate) Blends

The interest in bio-based alternatives to classical polyesters such as poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) is steadily growing to achieve a more sustainable approach to polymer materials. In this study, PBT/poly(butylene furanoate) (PBF) blends are prepared, characterized and extrusion foamed. PBF as a bio-based polyester offers two advantages. The ecological footprint of the material is reduced, and additionally, it can be used in Diels-Alder reactions at the blend surface to support fusion of the foamed beads. The blending behavior of the polyesters is investigated using samples prepared in a microcompounder, particularly focused on the miscibility of the blends and transesterification reactions. The blends are thermodynamically immiscible but show a certain degree of transesterification according to nuclear magnetic resonance (NMR) spectroscopy. The morphology of blend beads produced by an extrusion foaming process is analyzed regarding their cell density, cell size distribution, and open-cell content. It is shown that PBF has a positive effect on the bead foam morphology. The use of a bifunctional linker designed for chemical fusion of the bead surfaces allows to obtaining of molded parts, in contrast to beads containing pure PBT.     

Miscibilities and rheological properties of poly(butylene succinate)–Poly(butylene terephthalate) blends

An aliphatic/aromatic polyester blend has been dealt with in this study. As an aliphatic polyester, poly(butylene succinate) (PBS) was used, which is thought to possess biodegradability, but it is relatively expensive. It has been blended with poly(butylene terephthalate) (PBT) in order to obtain a biodegradable blend with better mechanical properties and lower cost. The miscibilities of PBS–PBT blends were examined not only from the changes of T_g but also from log G′–log G" plots. Dynamic mechanical thermal analyzer (DMTA) was an appropriate, sensitive method to obtain the glass transitions properly. Thermal stabilities of PBS and PBT were also verified at the temperature of 240°C. A transesterification reaction between two polyesters at 240°C was hardly detectable so that it did not affect the miscibilities and properties of the blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 945–951, 1999     

ABS-g-GMA增韧聚对苯二甲酸丁二醇酯的研究

用甲基丙烯酸环氧丙酯（（MA）接枝的丙烯腈／丁二烯／苯乙烯（ABs）接枝共聚物（ABS-g-GMA）改善聚对苯二甲酸丁二醇酯（PBT）的缺口冲击韧性。动态力学分析、差示扫描量热分析以及流变性能测试结果表明，GMA引入到ABS中，随GMA含量的增加，PBT与ABS的玻璃化转变温度相互靠近，PBT的熔点降低，共混体系的扭矩、温度提高，这些结果表明GMA提高了PBT与ABS之间的相容性；增容反应导致ABS在PBT基体中均匀、稳定分散，有利于共混物性能的改善；交联反应导致交联聚集网状结构的生成，使共混物性能变差。冲击强度结果表明，1％（质量含量。下同）GMA含量就可以导致PBT／ABS-g-GMA共混物冲击韧性显著改善，当ABS-g-GMA1含量为30％时，共混物冲击强度高达850J／m。     

Fabrication and Properties of Modified Poly(butylene terephthalate) with Two-Step Chain Extension

High-viscosity, low-crosslinked poly(butylene terephthalate) (PBT) from organic chain extenders and inorganic particles are prepared. PBT modification adopted from multifunctional, commercially available chain extension containing nine epoxy groups (ADR9) occurs in the first-step chain extension; hydroxyl addition modified dioxazoline (BOZ) serves as the second step. Anion stratiform inorganic hydrotalcite (HT) is used to adjust the crystallization behavior and damp-heat aging properties of PBT. The reaction between the chain extender and PBT end-groups such as carboxyl (–COOH) and hydroxyl (–OH) enhances the interfacial bonding between the PBT matrix and dispersed HT phases. With a fraction of chain extenders in the PBT matrix, the chain-extended PBT exhibits higher mechanical properties, intrinsic viscosity, average molecular weight, and melt viscosity than those of unmodified PBT. Damp-heat aging resistance measurements show correlation with initial carboxyl content in the resin. Reducing the concentration of carboxyl end-groups in the resin is shown to increase hydrolytic stability. The modified PBT resin can be used in optical fiber communication cable industry for its high level of damp-heat aging resistance as well as good mechanic properties.     

PBS/PBAT共混型全生物降解材料的制备及其性能研究

通过熔融共混法制备了聚丁二酸丁二醇酯（PBS）/聚己二酸对苯二甲酸丁二酯（PBAT）共混物,用熔体流动速率法、扫描量热法、X射线衍射、扫描电镜法及力学性能测试等手段研究了PBS/PBAT共混物的熔体流动性、结晶性能、力学性能以及共混物相容性。结果表明,随着PBAT含量的增加,PBS/PBAT共混体系的拉伸强度先升高后降低,断裂伸长率不断提高,冲击强度先降低后提高;当PBAT含量为20 %（质量分数,下同）时,与纯PBS相比,断裂伸长率提高10倍,冲击强度提高82 %,而拉伸强度仅仅降低6 %。     

聚对苯二甲酸甲二酯的热分解行为及其动力学研究

研究了惰性气氛下聚对苯二甲酸甲二酯(PMT)的非等温热分解行为及其动力学,并与聚对苯二甲酸丁二酯 (PBT)进行了对比。研究发现,PMT的热降解过程包括两个主要失重阶段,其热分解反应不是一级反应。第一阶段的起始分解温度较低是由于产物的分子链末端基中含有Br或Cl能催化聚合物的降解反应;第二阶段为分子链主体的热分解过程,由于分子链中苯环的密度较大,分子链的热稳定性比具有较低苯环密度的PBT要高。而PBT的降解失重过程仅为一个阶段,为一级反应。