超纤合成革基布用新型共聚醚酯的结构与性能设计

设计并合成了一系列含有磺酸盐基团化合物和不同聚乙二醇(PEG)添加量的新型共聚醚酯(COPEET),研究了它们的常规性能、玻璃化转变温度、结晶温度、熔融温度及热失重等性能随PEG添加量的变化,又将COPEET与低密度聚乙烯(LDPE)以60/40的质量比进行共混熔融纺丝,可纺性好,并得到了以COPEET为分散相的基体-微纤型纤维,经剥离后得到线密度低于0.001 dtex的超细纤维,可用于制成超纤合成革。     

PET-PEG共聚物及其纤维的制备及性能研究

通过共聚反应合成了含不同相对分子质量聚乙二醇(PEG)及其添加量的聚对苯二甲酸乙二醇酯(PET)-PEG嵌段共聚物,经熔融纺丝制备PET-PEG共聚酯纤维。利用核磁共振氢谱、差示扫描量热分析、X射线衍射(XRD)等手段对共聚酯的结构及其热性能进行了表征。结果表明:核磁共振氢谱证实了共聚酯为PET-PEG目标产物;随着PEG相对分子质量从800增加到6 000,PET-PEG共聚酯的熔融温度从243.97℃增加到253.55℃,冷却结晶温度从176.32℃增加到189.25℃,表面接触角从74.2°下降到62.3°,共聚酯纤维在标准环境下的回潮率从0.51%增加到0.68%;在PEG相对分子质量为2 000时,添加PEG相对对苯二甲酸(PTA)质量分数为0~20%时,共聚酯的熔融温度与冷却结晶温度随着PEG添加量的增加呈下降趋势,共聚酯纤维的回潮率呈指数增加;PEG添加量相对PTA质量分数为20%时,共聚酯可纺性较差;XRD表明PEG在结晶过程中并不进入PET晶格中,为了保证共聚酯的良好吸湿性能和力学性能,PET-PEG的共聚合反应时,PEG适宜的相对分子质量为2 000,添加量相对PTA的质量分数为10%。     

共聚醚酯的热失重研究

利用热失重分析法(TG),研究了所合成的一系列含有磺酸盐基团的间苯二甲酸二乙二酯-5-磺酸钠(SIPE)、对苯二甲酸乙二酯(BHET)和不同聚乙二醇(PEG)添加量的共聚醚酯(COPEET)在N2和空气气氛下,受热发生分解释放出小分子而失重的规律。结果表明:随聚乙二醇质量分数的增加,COPEET的热失重起始温度提前,且失重速率加快;在N2气氛下,COPEET的热失重起始温度均为350℃左右,而在空气气氛下的起始分解温度比在N2气氛下提前许多;在N2气氛下的热失重曲线只显示出一次分解现象,留下部分残留物,聚乙二醇添加量越多则残留物越少;而在空气气氛下会出现第二次甚至第三次分解,且残留物极少。     

聚乙二醇对聚羟基丁酸戊酸酯(PHBV)热特性和力学性能的影响

以聚乙二醇(PEG)为增塑剂、聚羟基丁酸戊酸酯(PHBV)为基体相,采用熔融共混法制备生物可降解PEG/PHBV复合材料。采用差示扫描量热仪(DSC)、热重分析仪(TG)、力学试验机探讨了PEG的添加量(5%~25%)对复合材料的结晶性能、热稳定性和力学性能的影响。结果表明,PEG的加入使得PHBV复合材料在较低的温度下形成更加完善的晶体,同时使得复合材料的结晶过程变得更加困难,结晶度下降。PHBV复合材料的热稳定性随着PEG添加量的增加先降低后升高,当PEG添加量为25%时,热稳定性能达到最佳。力学性能表明,PEG的加入使得PHBV复合材料的拉伸断裂伸长率和冲击强度显著提高,较纯PHBV增幅最大为57.0%和251.9%,复合材料的韧性得到明显改善,但拉伸强度和拉伸模量有所降低。     

聚苯酯对聚醚醚酮结晶行为的影响

用模压法制备了聚苯酯(Ekonol)／聚醚醚酮(PEEK)复合材料，通过X射线衍射(XRD)、差示扫描量热分析(DSC)考察了PEEK的结晶行为，并测定了复合材料的熔点、结晶温度和玻璃化转变温度。结果表明：Ekonol含量的大小对PEEK的结晶行为产生了直接影响，PEEK的相对结晶度随着Ekonol含量的增加而提高；Ekonol含量小于30％时，对复合材料的熔点、结晶温度和玻璃化转变温度影响不大，但含量大于30％时，材料的结晶温度、熔融温度下降，玻璃化转变温度提高。     

PET共聚酯的热性能及其纤维的力学性能

直接酯化法合成了一系列聚对苯二甲酸乙二酯(PET)-间苯二甲酸双羟乙酯磺酸钠(SIPE)-聚乙二醇(PEG)共聚酯,以差示扫描量热分析法(DSC)研究了这些共聚酯及纯PET的熔融和结晶过程,并利用万能材料测试仪研究了纤维的力学性能。试验结果表明:加入SIPE和PEG后,共聚酯熔点(Tm)、玻璃化转变温度(T)g降低;随着PEG相对分子质量的增大,PET共聚酯的Tg、冷结晶温度(Tc)c、Tm、结晶温度降低(T)c,纤维的断裂强度和初始模量下降,断裂伸长率增加。     

PET-co-PEG共聚酯的制备及其结晶行为的研究

以对苯二甲酸、乙二醇、聚乙二醇(PEG)为原料,通过直接酯化-缩聚法制得不同PEG含量的共聚酯(PET-co-PEG),并用差示扫描量热(DSC)仪、X射线衍射(XRD)仪对PET-co-PEG的结晶性能进行了表征。结果表明:PEG的引入使得PET的玻璃化转变温度、冷结晶温度、熔点降低,且随着PEG添加量的增加,降低幅度增大,结晶过冷度和过热度增加,结晶变难;在118~178℃等温冷结晶过程中,PEG质量分数为15%的PET-co-PEG试样的Avrami指数为1.23~1.59,在等温结晶温度为148℃时,试样结晶速率最高,结晶速率常数达1.7 min~(-1),而在133℃结晶完全时试样的结晶度最高,XRD结果显示在133℃完成等温结晶时,衍射峰强度和结晶度最高,表现出与DSC测试结果类似的变化规律。     

聚乙二醇增塑聚乳酸复合薄膜的制备与性能研究

通过溶液共混法,以三氯甲烷为溶剂,分别以聚乙二醇200(PEG200)和聚乙二醇1000(PEG1000)作为增塑剂制备了PEG增塑的聚乳酸复合薄膜。通过机械拉伸、热重、XRD和DSC对复合薄膜的力学性能、热稳定性以及热性能进行了表征。结果表明:PEG的加入能有效增强聚乳酸的柔性,断裂伸长率随PEG含量的增大明显升高,拉伸强度则随之降低,且少量添加时PEG200比PEG1000的增塑效率更高;增塑的聚乳酸薄膜低温热稳定性下降,冷结晶温度(t_c)和熔融温度(t_m)降低,结晶能力大幅提高,添加量为15%(质量分数)时PEG200和PEG1000增塑的聚乳酸薄膜结晶度(X_c)分别达到41.06%和50.15%。     

聚酰胺酯结晶行为研究

利用差式扫描量热法对聚酰胺酯进行结晶行为分析。结果表明:与常规PET相比,聚酰胺酯玻璃化温度、冷结晶温度、熔点、熔融结晶温度均较低,同时其熔融结晶速率也较慢;且随着共聚酯中聚酰胺成分的增加,玻璃化温度、熔点、熔融结晶温度逐渐降低并呈现一定的变化关系;在相同结晶温度下,聚酰胺成分增加,共聚酯半结晶周期t_(1/2)增加,结晶随之变慢。     

COPEET/HSPET并列复合纤维结晶和热收缩性能的研究

以共聚醚酯(COPEET)及高收缩聚酯(HSPET)为原料,经熔融复合纺丝,制备了COPEET/HSPET初生纤维,将初生纤维经不同热定型温度处理及2倍拉伸后,制得COPEET/HSPET并列复合纤维;对所纺纤维进行热处理,研究了热定型温度、热处理工艺条件对COPEET/HSPET并列复合纤维结晶结构和热收缩性能的影响。结果表明:当热定型温度在150~180℃时,随着热定型温度升高,COPEET/HSPET复合纤维两组分的热焓差越大,其潜在热收缩性越强;180℃热定型所制得COPEET/HSPET复合纤维经90℃,30 min的热处理,热收缩率最大,达52.65%;热收缩率较大的COPEET/HSPET复合纤维卷曲波幅小、卷曲数多且形态较不规整;沸水处理后复合纤维的结晶度明显增加。     

阳离子易染共聚酯的热性能研究

在半连续大装置上合成了含第三单体间笨二甲酸乙二脂-5-磺酸钠(SIPE),第四单体聚乙二醇(PEG)的阳离子易染共聚酯(ECDP);采用热失重分析、差示扫描量热法对ECDP的热性能进行了研究,并对ECDP切片干燥和熔融过程的特性粘数降进行了测试.结果表明:随行PEG含量的增加,ECDP的热分解温度下降,玻璃化转变温度相...     

Effect of crystallinity on enthalpy recovery peaks and cold‐crystallization peaks in PET via TMDSC and DMA studies

Poly(ethylene terephthalate) (PET) sheets of different crystallinity were obtained by annealing the amorphous PET (aPET) sheets at 110°C for various times. The peaks of enthalpy recovery and double cold‐crystallization in the annealed aPET samples with different crystallinity were investigated by a temperature‐modulated differential scanning calorimeter (TMDSC) and a dynamic mechanical analyzer (DMA). The enthalpy recovery peak around the glass transition temperature was pronounced in TMDSC nonreversing heat flow curves and was found to shift to higher temperatures with higher degrees of crystallinity. The magnitudes of the enthalpy recovery peaks were found to increase with annealing times for samples annealed ≤30 min but to decrease with annealing times for samples annealed ≥40 min. The nonreversing curves also found that the samples annealed short times (≤40 min) having low crystallinity exhibited double cold‐crystallization peaks (or a major peak with a shoulder) in the region of 108–130°C. For samples annealed long times (≥50 min), the cold‐crystallization peaks were reduced to one small peak or disappeared because of high crystallinity in these samples. The double cold‐crystallization exotherms in samples of low crystallinity could be attributed to the superposition of the melting of crystals, formed by the annealing pretreatments, and the cold‐crystallizations occurring during TMDSC heating. The ongoing crystallization after the cold crystallization was clearly seen in the TMDSC nonreversing heat flow curves. DMA data agreed with TMDSC data on the origin of the double cold‐crystallization peaks. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of the polyethyleneglycol content on the properties of ethyleneglycolterephthalate/polyethyleneglycol terephthalate copolymers

The effect of the polyethyleneglycol (PEG) content on the properties of the ethyleneglycol terephthalate (EGT)/polyethyleneglycol terephthalate (PEGT) copolymers has been studied. The PEG content varied over a wide range (5-70% PEG). To obtain information on the solubility and on the thermal properties, the following methods: turbidimetry, differential scanning calorimetry (DSC), thermogravimetry and differential thermogravimetry (TG, DTG) have been used. The turbidimetric characteristics are dependent on composition copolymers. The incorporation of increasing amount of PEG 4000 in EGT/PEGT copolymers has a pronounced effect on the properties: increases viscosity and solubility of copolymers, decreased glass transition, cold crystallization and melting temperatures and also decreased crystallization and melting heat. These changes are desirable for better processing of these copolymers comparatively with PET in products with higher elasticity and hydrophilicity. It must be take into account, however, that above 20 wt% PEG the copolymers the thermal stability is significantly affected.     

不同PEG含量对PLA/PEG共混物结晶动力学的影响

采用溶液共混法制备了一系列不同配比的聚乳酸(PLA)/聚乙二醇(PEG)共混物。通过偏光显微镜(POM)、扫描电镜(SEM)和差式扫描量热仪(DSC)研究了不同PEG含量的PLA/PEG共混物在不同结晶温度下,聚乳酸的晶体形貌、球晶生长速率及热力学性能。研究发现,PEG能够显著提高聚乳酸球晶的生长速率。当PEG含量为60%时,PLA/PEG共混物中聚乳酸球晶的生长速率最快,达到23.6μm/min,比纯聚乳酸的最快球晶生长速率(0.5μm/min)高47倍。但是,当PEG含量高于60%时,聚乳酸球晶的生长速率有所降低。同时,PLA/PEG共混物中聚乳酸球晶速率随结晶温度变化的取向,均向低温移动。另外,PLA/PEG共混物中聚乳酸球晶呈现环状花纹。DSC测试结果表明,随着PEG含量的增加,PLA/PEG共混物的玻璃化转变温度明显降低。     

Properties and weldability of plasticized polylactic acid films

The objectives of the presented work were to investigate films based on polylactic acid (PLA) and polyethylene glycol (PEG) in order to improve ductility and weldability of PLA films. The effect of plasticizer amount on the thermal, rheological, and mechanical properties of PLA plasticized films was investigated. The PEG content does affect the glass transition and the cold crystallization temperature of PLA in blends, while the melting temperature was not affected by the addition of PEG. The complex viscosity of the neat PLA granules and of plasticized films showed strong temperature and angular velocity dependence. The Young's modulus and tensile strength of plasticized films were improved with increasing plasticizer concentration, while the elongation at break stays rather constant. Plasticized PLA films were furthermore heat welded. These investigations showed that plasticized PLA films can be welded by heat welding. The obtained weld strength is strongly depending on the PEG amount as well as on selected welding parameters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40394.     

Structure-property relationships in novel poly(imide-amide)-poly(ethylene glycol) hybrid networks

Broadband dielectric relaxation spectroscopy (DRS), thermally stimulated depolarisation currents (TSDC), differential scanning calorimetry (DSC) and to a lesser extent water uptake measurements, were employed to investigate molecular mobility, morphology and crystallization/melting events of PEG in poly(imide-amide)-polyethylene glycol hybrid networks (PIA-PEG) with short (M_n=1000 g/mol) and long (M_n=3400 g/mol) PEG crosslinks. The results obtained suggest long range connectivity of the PEG component in the hybrids with short PEG crosslinks at PEG content higher than 40 wt% and in these with long PEG crosslinks at PEG content higher than 20 wt%. Crystallization of the PEG component is observed by DSC in the hybrids with the longer crosslinks at sufficiently high content of PEG, only. The glass transition temperature, T_g, of PEG component in the hybrids with the shorter PEG crosslinks is shifted to higher temperatures compared to that of the hybrids with longer PEG crosslinks, while suppression of the glass transition of the PEG component is observed in the hybrids with the shorter PEG crosslinks at PEG content lower than 40 wt%. The results are discussed in terms of constraints to segmental motion of the PEG crosslinks, imposed by fixed PEG chain ends on the rigid PI chains.     

温度调制热分析技术对预吸热峰的研究

以快速的冷却速率冷却熔体获得的金属玻璃通常远离平衡状态。如果在适当温度经过合适时间退火后,在热流曲线上玻璃转变温度之前会产生明显的预吸热峰。使用常规差示扫描量热法(DSC)和温度调制差示扫描量热法(TMDSC)对Pd₄₀Ni₁₀Cu₃₀P₂₀和Au₄₉Ag_5.5Pd_2.3Cu_26.9Si_16.3两种金属玻璃进行研究。结果表明,预吸热峰从玻璃态到过冷液态是一个连续演变过程,当预吸热峰出现在玻璃转变温度之下时,预吸热峰向高温移动过程中对玻璃化转变过程没有影响。然而,当预吸热峰出现在玻璃化转变温度以上时,玻璃转变开始温度会随着预吸热峰值的增加而增加,因此金属玻璃的动力学稳定性得到了提高。实验结果对理解预吸热峰从玻璃态到过冷液态过程中的稳定变化具有重要意义。     

改性共聚酯切片的化学结构及热性能

在30 L聚合装置上,成功制备了一系列用聚乙二醇(PEG)和间苯二甲酸乙二醇酯-5-磺酸钠(SIPE)改性的共聚酯切片(MECDP)。核磁氢谱(1H-NMR)的测试结果表明:聚合物大分子链中的精对苯二甲酸(PTA)与SIPE单元的摩尔比以及PTA与PEG单元的质量比,与其相应的投料比基本一致;共聚酯的分子链化学结构与设想的分子链化学结构大致吻合。差示扫描量热法(DSC)试验结果表明:玻璃化转变温度(T)g、冷结晶温度(Tc)c和熔点(Tm)均随着PEG质量分数的增加而逐渐下降。色度(b值)变化的测试结果表明:PEG的质量分数越高,干燥温度越高,干燥时间越长,其b值会变得越大。     

Thermal behaviour of poly(lactic acid) in contact with compressed carbon dioxide

BACKGROUND: The thermal behaviour of poly(lactic acid) (PLA) in contact with compressed CO₂ was studied using high‐pressure differential scanning calorimetry. In particular, the effect of annealing below and above the glass transition temperature (T_g) on the glass transition, cold crystallization and melting temperatures was studied systematically as a function of annealing time and pressure. RESULTS: The effect of compressed CO₂ on the thermal properties of PLA is time dependent. Annealing below T_g decreases the temperature and enthalpy of cold crystallization. Similar, but more evident, behaviours are observed when annealing above T_g. Crystallization temperature and enthalpy during cooling decrease with increasing pressure, and the peak is narrower. CONCLUSION: Annealing PLA in the presence of compressed CO₂ accelerates cold crystallization, but retards crystallization during cooling. Copyright © 2009 Society of Chemical Industry