二甘醇改性PETG共聚酯流变性能研究

为了提高聚对苯二甲酸乙二醇-1,4环己烷二甲醇酯(PETG)的加工流动性能,在分子链中引入柔性的二甘醇(DEG)结构,制备了DEG含量分别为1.16%、1.6%、2.03%的PETG改性共聚酯。采用毛细管流变仪研究了PETG改性共聚酯的流变性能。结果表明,不同DEG含量的PETG的剪切黏度随剪切速率的增高而降低,且非牛顿指数均小于1;在相同的剪切速率下,DEG含量越高,PETG的黏流活化能越小,共聚酯越容易在低温下产生流动,熔体黏度也会相应降低,说明DEG有利于改善熔体的流动性,使其加工性能提高。     

羟乙基化双酚A共聚改性PET的合成与表征

本文以对苯二甲酸(PTA)、乙二醇(EG)为主要原料,添加第三单体羟乙基化双酚A(BPE)经过直接熔融缩聚法合成了一系列不同BPE含量的共聚酯,研究分析了共聚酯的常规性能,利用1H-NMR、差式扫描量热法(DSC)研究了共聚物的链结构及热性能。结果表明:所得共聚物无规度值均接近1,为无规共聚物。随着BPE含量的增加,共聚酯二甘醇(DEG)含量逐渐下降;玻璃化转变温度(Tg)略微下降,熔融温度(Tm)、热结晶温度(Tmc)逐渐下降,冷结晶温度(Tc)逐渐上升,这些表明共聚酯的规整性、结晶能力随BPE用量的增加而下降。     

新戊二醇改性PET的合成研究

以对苯二甲酸（PTA）、乙二醇（EG）为主要原料,添加第三单体新戊二醇（NPG）合成了一系列不同NPG含量的共聚酯（PENT）,研究了NPG对酯化、缩聚过程的影响,分析了PENT共聚酯的常规性能。结果表明,酯化反应速率和聚合反应速率随NPG含量的增加而下降,共聚酯中的二甘醇（DEG）含量和端羧基（CEG）含量随NPG含...     

DSC研究二甘醇含量对PET热行为的影响

<正> 聚对苯二甲酸乙二酯(PET)的合成,无论是采用酯交换法还是直接酯化法,都由于反应过程中的副反应而导致二甘醇(DEG)存在于聚酯链中,从而使聚酯链中除了酯键外,还含有醚键。实验已证明,PET中DEG的存在会严重损害纤维的性能,例如机械性能、     

二甘醇在聚氨酯方面的应用

一、前言二甘醇是由环氧乙烷和乙二醇反应生成的低分子二元醇,即一缩二乙醇(简称DEG).分子式:C_(4)H_(10)0_(3);分子量:106.12;比重:d_(20)~(20): 1.1184;沸点:245℃;熔点:-8℃;酸值:<0.15毫克KOH/克;水份:<0.2%.作为聚氨酯合成材料的原料,最开始是作为合成聚酯的原料而被大量应用的.二甘醇和低分子二元酸缩合生成聚酯多元醇.反应如下:     

毛细管气相色谱法研究共聚酯中CHDM的含量

在GB/T14190-2008中DEG测试方法的基础上,对气相色谱法的色谱柱、柱温、分流比与进样量以及试样前处理的醇解时间与醇解温度等条件进行了系统探索,确定了同时分析共聚酯中1,4-环己烷二甲醇(CHDM)和二甘醇(DEG)含量的色谱条件与试样前处理条件,验证了气相色谱法分析共聚酯中CHDM含量的可行性,比较了CHDM理论加入量与共聚酯中实际值之间的差异。结果表明:采用毛细管气相色谱法分析共聚酯中CHDM含量,精密度高、准确度优、可行性强。     

水性聚氨酯在PET薄膜上附着力影响因素的探究

采用不同分子结构的低聚物二醇和二异氰酸酯为原料制备了一系列水性聚氨酯(WPU)树脂,对比分析了低聚物二醇、异氰酸酯和扩链剂种类对WPU在PET薄膜上附着力的影响;同时也探讨了低聚物二醇分子量、异氰酸酯指数(R值)以及交联剂用量对其在PET薄膜上附着力的影响。结果表明:采用间苯二甲酸聚酯二醇(PIA)、甲苯二异氰酸酯(TDI)、一缩二乙二醇(DEG)合成的WPU对PET薄膜的附着力最好,且配制的油墨手感好,不发粘; WPU对PET薄膜的附着力会随着低聚物二醇分子量的增大而增加,随着R值或交联剂用量的增加而减小。     

1,2-丙二醇在聚酯合成中的应用研究

以1,2-丙二醇作为改性共聚酯合成过程中的二元醇组分,采用对苯二甲酸(PTA)、乙二醇(EG)和1,2-丙二醇为基本原料,通过熔融缩聚的工艺路线,得到改性共聚酯新材料,对1,2-丙二醇在聚酯合成中的应用进行研究。     

二甘醇对染色性能的影响

聚酯生产中,生产原料、生产负荷、工艺参数等因素的变化,均有可能对成品中二甘醇(DEG)的含量造成影响,如控制不当,会严重影响纤维的染色均匀性。通过DEG对聚酯染色性能的影响机理及影响DEG含量的因素的分析,提高调控水平,确保DEG含量稳定,避免纺丝染色出现明显色差。     

PET/PEG共聚反应的动力学研究

在试管合成装置上,以酯化率93%的BHET和分子质量不同的各种PEG为原料,合成了一系列PET均聚酯和PET/PEG共聚酯,研究了共聚酯与均聚酯的反应动力学差异。研究发现,反应温度、时间等工艺条件对(共)聚酯的缩聚反应速度有很大的影响,在相同的工艺条件下,(共)聚酯的反应速度快于PET。     

Synthesize and Crystallization Kinetics of Biodegradable Aliphatic Poly(Butylene Succinate-Co-Diethylene Glycol)

Biodegradable aliphatic poly(butylene succinate-co-diethylene succinate) (PBDEGS) were synthesized from succinic acid and diethylene glycol through a two step polycondensation with titanium tetraisoproxide (TTP) as catalyzer and polyphosphate (PPA) as the stablilizer at high temperature. The differential scanning calorimeter (DSC) was used to investigate the melting behavior, crystallization behavior and non-isothermal crystallization kinetics of this copolyester. The melting behavior showed that the melting temperature of the copolyester decreased gradually with increaseing of diethylene glycol in the copolyester. The crystallization mechanism of PBDEGSs were analyzed with the Avrami equation. The result showed that the DEG chains affected the crystallization mechanism of PBS and decreased overall crystallization rate in some extent. The contrastive method of Mo analysis showed similar rasult. At the same time, because of the flexible ether bond existed in the DEG molecules, the crystallization activation energy of PBDEGSs is obviously lower than that of PBS.     

含两种不同共聚组分改性聚酯的结晶速率

添加己二酸、间苯二甲酸,聚乙二醇对PET进行改性,合成样品。用DSC法研究合成共聚物的等温结晶动力学。结果表明,在所选择的温度范围内,共聚物很好的符合Avrami方程。随温度的升高,共聚物的结晶速度常数K和Avrami指数n逐渐减小,结晶速度G逐渐降低。含2种柔性组分的共聚酯随着一种柔性组分含量的增加,结晶速率G上升;含一种刚性一种柔性组分的共聚酯随刚性组分含量的增加,结晶速率G下降。     

Pervaporative dehydration of diethylene glycol through a hollow fiber membrane

In this study, the pervaporative dehydration of diethylene glycol (DEG) through a commercial hollow fiber membrane was investigated at various feed temperatures in the range of 333–363 K with feeds containing 0.5–2.0 wt % water. Unlike the usual pervaporative dehydration process in which water is less volatile than the organic solvent, the feed mixture used in this study contained the organic component DEG, which is less volatile than water, resulting in unique permeation behaviors. The permeation behaviors of the individual components were investigated as functions of the feed temperature and feed composition. In particular, the effect of the low vapor pressure characteristics of DEG was investigated. Semi‐empirical equations for predicting the individual component fluxes and separation factor were quantified directly from actual dehydration pervaporation of DEG. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

低熔点共聚酯的合成及性能研究

介绍了一种可用于纺丝的低熔点共聚酯的合成工艺及其纺丝性能。通过改变其组分降低聚酯的熔点,研究表明共聚酯的熔点随第三组分含双羟端基单体的加入量增加在一定范围内呈线性降低,当第四组分丁二醇的加入量为所加醇总量摩尔比的40％时,可得熔点为128％的共聚酯,所得共聚酯具有一定的结晶性和良好的纺丝性能。通过DSC、X射线衍射、红外光谱法等对共聚酯切片及其纤维性能进行了表征。结果表明,共聚酯中的亚甲基含量增高。通过提高亚甲基含量,可降低熔点,具有一定的结晶能力。     

二甘醇对涤纶染色性能的影响

介绍了聚对苯二甲酸乙二酯(PET)纤维中二甘醇(DEG)的生成机理,分析了DEG对PET纤维(涤纶)染色性能的影响;阐述了涤纶中DEG含量的测试方法。PET中DEG有游离DEG、链内DEG与链端DEG3种形式,其中链内DEG的含量对涤纶染色均匀性及稳定性起重要作用。在配料时添加质量分数0.29%的DEG,55 dtex/144 f涤纶FDY的染色一等品率由85%提高到95%。建议采用高频核磁共振仪检测PET链内的DEG含量,可精确控制DEG含量,以提高涤纶染色的稳定性。     

橡胶替代品的耐热性共聚聚酯弹性体研究

研究橡胶替代品的耐热性共聚聚酯弹性体。通过对热塑性共聚聚酯解决方案、成功愿景、HT TPC导管工程、材料的热老化性能、部件性能、部件验证等方面的探讨,结果表明:热塑性共聚聚酯能降低系统成本,减轻重量,降低复杂程度,潜在泄露途径少,应用前景良好。     

Thermal decomposition behavior of carbon nanotube reinforced thermotropic liquid crystalline polymers

Thermotropic liquid crystalline polymers (TLCP), 4‐hydroxybenzoic acid (HBA)/6‐hydroxyl‐2‐naphthoic acid (HNA) copolyester, and HNA/hydroxylbenzoic acid (HAA)/terephthalic acid (TA) copolyester reinforced by carbon nanotube (CNT) were prepared by melt compounding using Hakke internal mixer. The thermal behavior and degradation of CNT reinforced HBA/HNA copolyester and HNA/HAA/TA copolyester have been investigated by dynamic thermogravimetric analysis under nitrogen atmosphere in the temperature range 30 to 800°C to study the effect of CNT on the thermal decomposition behavior of the TLCP/CNT nanocomposites. The thermal decomposition temperature at the maximum rate, residual yield, integral procedural decomposition temperature, and activation energy for thermal decomposition was studied to investigate thermal stability of TLCP/CNT nanocomposites. The thermal stability of CNT reinforced HBA/HNA copolyester was increased by addition of a very small quantity of CNT and the residual weight was 42.4% and increased until 50.8% as increasing CNT contents. However, the thermal stability of CNT reinforced HNA/HAA/TA copolyester was decreased initially when a very small quantity of CNT added. The residual weight was decreased from 50.4% to 45.1%. After addition of CNTs in the TLCP matrix, the thermal stability of CNT reinforced HNA/HAA/TA copolyester increased as increasing content of CNT and the residual weight was increased until 53% as increasing CNT contents. The activation energy was calculated by multiple heating rate equations such as Friedman, Flynn‐Wall‐Ozawa, Kissinger, and Kim‐Park methods to confirm the effect of CNT in two different TLCP matrices. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

间苯二甲酸共聚酯的流变特性

对聚对苯二甲酸乙二醇酯（ＰＥＴ）中加入间苯二甲酸的无规共聚酯（Ａ２）的流变性能进行了研究。结果表明：Ａ２熔体是切力变稀流体;共聚酯大分子中第三组分的加入,使体系粘度降低,粘流活化能比ＰＥＴ高,表明共聚酯粘度对温度的敏感性较大;同一温度下,共聚酯的非牛顿指数比常规聚酯的高,说明共聚酯的流动偏离牛顿流体的程度小;共聚酯的弹性雷诺指数有所升高,但相对于常规聚酯的变化量不大。     

MELTING BEHAVIOR OF POLYETHYLENE TEREPHTHALATE COPOLYESTER AND POLYSTYRENE BLENDS

The melting behavior of polyethylene terephthalate (PET) copolyester/polystyrene (PS) blends was studied using differential scanning calorimetry. Multiple melting endotherms were observed for the PET copolyester as well as the PET copolyester/PS blend at T_c = 483 and 493 K, respectively. A higher crystallization temperature resulted in the reorganization of the crystalline species and an increase in area under the reorganization peak. Higher melting temperatures for PS-rich blends may be attributed to the formation of a stiffer matrix around the crystallites and the possible inhibition of crystal thickening. Melting behavior shows that the PET copolyester and PS form miscible blends up to 30 wt.% of PS, whereas with the lowering of the isothermal crystallization temperature to 483 K, miscibility was found only up to 10 wt.% of PS.