长链烷基胺氢卤酸盐的热致相变

差示扫描量热法（ＤＳＣ）结果表明，烷基胺氢卤酸盐化合物的相变温度与化合物烷基链链长之间存在明显的规律性，固－固结构相变的主相变峰温随烷基链链长的递增而升高，其逆相变过程表现出明显的热滞后现象；而熔融相变温度则随烷基链链长的递增而降低；实验结果还表明，试样的陈化放置过程以及结晶过程中所用的溶剂对化合物的热致相变历程都有明显的影响。     

接枝共聚法制备聚乙二醇(PEG)/聚乙烯醇(PVA)高分子固-固相变材料性能研究

用接枝共聚法将具有相变特征的聚乙二醇(PEG)接枝到具有较高熔点的聚乙烯醇(PVA)主链上,得到了系列性能稳定的PEG/PVA高分子固-固相转变材料,用DSC,WAXD和POM对其相变行为及形态结构进行了研究.结果表明,该材料呈现出可逆的固-固相转变特性;其结晶峰值温度和相变焓比纯PEG低,接枝率对相变温度和归一化相变焓影响不大;接枝率只影响结晶与熔融行为,不影响结晶结构.     

聚对苯甲酰胺薄膜的结构

聚对苯甲酰胺溶于ＤＭＳＯ ＮａＨ系中，变成聚合物阴离子，形成均相溶液．从此溶液中蒸发掉ＤＭＳＯ，用有机溶剂再生后获得再生薄膜．室温下干燥的薄膜基本上是无定形的，１３０℃的热处理对薄膜的结构几乎不发生大的影响，２５０℃或者３００℃的热处理后，薄膜的结构由无定性变成结晶１型及新的结晶２型．与结晶１型相比，结晶２型的ｄ＝０４９ｎｍ与ｄ＝０２８ｎｍ的反射强烈出现，而且相对于结晶１型的ｄ＝０３１ｎｍ的反射看不见或者看不清楚     

纳米二氧化锆制备过程的DSC、TGA和XRD研究

用ＤＳＣ、ＴＧＡ和ＸＲＤ技术研究了在沉淀法制备纳米ＺｒＯ２的过程中，残留ＮＨ４Ｃｌ、ｐＨ值、滴加方式、以及结构稳定剂Ｙ２Ｏ３的添加量对结晶过程的影响。结果表明，残留ＮＨ４Ｃｌ使结晶化温度降低，使放热过程变为吸热过程。而ｐＨ值、滴加方式和结构稳定剂的添加对结晶过程无明显影响。     

丙烯腈-衣康酸共聚物接枝聚乙二醇固-固相变材料的制备及表征

将衣康酸与丙烯腈共聚,构建具有双端羧基活性点的聚合物骨架,以二苯甲烷二异氰酸酯(MDI)为桥基,将聚乙二醇(PEG)接枝到聚合物骨架上,制备了丙烯腈-衣康酸共聚物接枝聚乙二醇(AIPCMs).采用红外光谱、差示扫描量热、X射线衍射、偏光显微镜、热失重及水静态接触角等方法研究了其结构、相变潜热性能、结晶性能、结晶形态、热稳定性及亲水性.结果表明,合成的AIPCMs具有固-固相变特性及优异的热储能性能,相变潜热达到70.5 J/g.化学接枝改变了AIPCMs中PEG的结晶结构及结晶形态.AIPCMs的热稳定性优异,初始分解温度达289℃,并且其亲水性较好,接触角最小可达33.71°.     

涤纶三维卷曲中空纤维结构性能研究 Ⅰ.涤纶中空纤维在纺丝及后加工过程中结构变化特征

用ＦＲＳ－ＸＲＳＡ、ＳＡＸＳ、ＤＳＣ表征了涤纶中空纤维在整个纺丝及后加工过程中结构的变化特征。结果表明，涤纶中空初生纤维基本是非晶态，在后加工过程中分两步结晶：拉伸应变诱导结晶和热结晶，在一次应变诱导结晶的同时伴随着纤维自卷形成三维卷曲，二次热结晶后形成长周期，使结构得以稳定。     

聚β-羟基丁酸酯/聚醋酸乙稀酯共混物结晶行为的研究

以ＤＳＣ，ＰＯＭ，ＷＡＸＤ实验方法研究了聚β－羟基丁酸酯／聚醋酸乙稀酯（ＰＨＢ／ＰＶＡｃ）共混体系的结晶行为。结果表明：随共混物中非晶组份ＰＶＡｃ含量的增加，ＰＨＢ结晶的活化能增大。用Ａｖｒａｍｉ方程处理实验数据，结果表明ＰＶＡｃ的加入对ＰＨＢ结晶的生长方式影响不大，但结晶速率却明显下降。ＷＡＸＤ实验表明，ＰＶＡｃ的加入不影响ＰＨＢ的结晶结构，但微晶尺寸和结晶度却明显变小。偏光显微镜观察结果与ＤＳＣ实验结果基本一致。     

热处理对聚乙烯／炭黑导电复合体系形态结构及PTC特性的影响

借助ＷＡＸＤ、ＳＡＸＤ和ＤＳＣ等手段研究了炭黑与聚乙烯复合体系在不同热处理条件下的结晶行为及聚集态结构的大尺寸效应对ＰＴＣ特性的影响。由此提出，不仅结晶度大小，而且聚集大尺寸效应性能对ＰＴＣ行性有重要影响的新观点。     

聚β—羟基丁酸酯／聚醋酸乙烯酯共温物结晶行为的研究

以ＤＳＣ，ＰＯＭ，ＷＡＸＤ实验方法研究了聚β－羟基丁酸酯／聚醋酯乙稀酯（ＰＨＢ／ＰＶＡｃ）共混体系的结晶行为。结果表明：随共混物中非晶组份ＰＶＡｃ含量的增加，ＰＨＢ结晶的活化能增大。用Ａｖｒａｍｉ方程处理实验数据，结果表明ＰＶＡｃ的加入对ＰＢＨ结晶的生长方式影响不大，但结晶速率却明显下降。ＷＡＸＤ实验表明，ＰＶＡｃ的加入入不影响ＰＨＢ的结晶结构，但微晶尺寸和结晶度却明显变小。偏光显微镜观察结果与Ｄ     

相变调温微胶囊的制备及其在PVA膜中的应用

采用类核壳乳液聚合法制备了相变调温微胶囊(Micro PCMs),并与聚乙烯醇(PVA)水溶液共混,制备了具有相变调温功能的PVA膜,对微胶囊及PVA复合膜的表面形貌、化学结构、耐热性能及相变调温等性能进行了研究,同时对PVA膜的断裂强度和拉伸强度进行了表征.结果表明,相变调温PVA膜的相变焓随MicroPCMs用量的增加而增大,当MicroPCMs与PVA的质量比为1∶1时,相变调温PVA膜的熔融焓与结晶焓分别为43.9和-44.8J/g,具有较好的相变调温功能.     

含两种不同介晶基团的半刚性共聚酯液晶态的结构研究

用Ｘ－光衍射，偏光显微镜及ＤＳＣ对含两种不同长度介晶基团４，４’－联苯二酚（Ⅰ）和对苯二甲酸二（对羟苯基）酯（Ⅱ）的系列共聚酯的液晶态进行了表征，据其液晶态中两种介晶单元的堆砌方式提出了可能的模型，这种模型很好地解释了液晶态的Ｘ－光衍射分布．     

含二羟基二苯酮热致液晶共聚酯的合成与表征（Ⅵ）──含二羟基二苯酮热致液晶共聚酯结晶结构的X射线衍射研究

以广角Ｘ－射线衍射（ＷＡＸＤ）对含二羟基二苯酮（ＢＨＰ）、对羟基苯甲酸（ＰＨＢＡ）、对苯二甲酸（ＴＰＡ）、问苯二酚（ＲＥＳ）的系列热致液品共聚酯进行了较为深入的研究，详细讨论了不同组成的共聚酯的结晶结构、结晶度、结晶颗粒大小等等。     

Synthesis and properties of novel photocrosslinkable aromatic-aliphatic liquid crystal copolyesters based on poly(ethylene glycol) and cinnamic acid

Firstly, PEGn-TA monomers with carboxyl functional groups were synthesised by terephthalic acid (TA) and poly(ethylene glycol) (PEG) with molecular weight of 200, 400 and 600. Then, photocrosslinkable thermotropic liquid crystal copolyesters derived from PEGn-TA, 4,4?-biphenol, 4-hydroxy-cinnamic acid and 4-hydroxy-benzoic acid were successfully obtained by Vilsmeier adduct solution polymerisation method. Influence of PEG molecular weight on thermal behaviour, liquid crystal mesophase, hydrophilicity, structure and photoactivity were investigated by various measurements. Experimental results indicated that all copolyesters showed nematic mesophase textures, relative low melting temperatures, and two glass transitions as well as better hydrophilicity were observed for those contained higher PEG molecular weight. Photocrosslinking rate was increased first and then decreased due to effect of flexible PEG moieties. The resulted copolyesters with liquid crystal behaviour, excellent hydrophilicity and photoactivity could be potentially used as biomaterial.     

Novel poly(butylene succinate-co-lactic acid) copolyesters: Synthesis, crystallization, and enzymatic degradation

A series of aliphatic biodegradable poly(butylene succinate-co-dl-lactide) (PBSLA) copolyesters were synthesized with the aim of improving the degradation rate of poly(butylene succinate) (PBS) by incorporation of dl-oligo(lactic acid) (OLA) into the PBS molecular chains. The composition and sequential structure of the aliphatic copolyesters were investigated by proton nuclear magnetic resonance (¹H NMR) spectroscopy. The crystallization behaviors, the crystal structure and morphology of the copolyesters were investigated by using differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM), respectively. The results indicate that the crystallization of the copolyesters was restricted by the incorporation of lactide (LA) units, which further tuned the mechanical properties of the copolyesters. The copolyesters could form complete spherulites and exhibit the same crystal structure as that of PBS. Enzymatic study indicated that the copolyesters with higher content of LA units degraded faster, and the degradation began in the amorphous regions and then in the crystalline regions. The morphology and the resulting degradation products of the copolyesters were investigated by scanning electron microscopy (SEM) and ¹H NMR analysis during the degradation process.     

PROPERTIES AND MICROSTRUCTURE OF AROMATIC LIQUID CRYSTALLINE COPOLYESTERS

The properties and structures of thermotropical liquid crystalline copolyesters basedon p-hydroxybenzoic acid (PHBA), terephthalic acid (TPA) and bisphenol A (BPA) werestudied by DSC, WAXD, hot stage polarized microscopy and NMR. It was found that mostof the copolyesters were soluble in many common organic solvents. The copolyesters hadfow T_m/T_f values and a broad range of liquid crystal phase, making the polymers readilymelt-processable. The effects of annealing at different temperatures on the copolyestercontaining 33% PHBA were also discussed. It was noted that annealing at ca. 200℃(below Tc - n) could lead to the increasing of the crystallinity of the copolyester while themicrostructure and sequence structure had not changed. Annealing at ca.280℃ (nearTc - n) could bring a change of crystal and sequence structure and simultaneously madethe ndcrodomains be ordered more perfectly.     

Direct synthesis of potentially biodegradable aromatic–aliphatic thermotropic copolyesters with photocrosslinking properties

ABSTRACT

In this study, aromatic–aliphatic thermotropic copolyesters derived from p-hydroxybenzoic acid, p-hydroxycinnamic acid (HCA), terephthalic acid and polyethylene glycol (PEG) with different molecular weight (200, 400, 600) were directly synthesised via Vilsmeier adduct solution polymerisation method. The structure, thermal behaviour, liquid crystal property, hydrophylicity and photoactivity were investigated by Fourier transform infrared and nuclear magnetic resonance spectroscopy, differential scanning calorimeter, polarised optical microscopy, water contact angle measurement and ultraviolet (UV) spectrophotometer. The PEG incorporation ratio is 0.540–0.691 related to the HCA units, because of its low reactivity. And, the copolyesters have relatively low melting temperatures (96–107°C) and good hydrophylicity (water contact angle value 61.2–75.3°) as compared with wholly aromatic thermotropic copolyester. All of the copolyesters exhibited nematic liquid crystal behaviour and the stable mesophase temperature range was more than 60°C after being melted. The resulted copolyesters had enough thermal stability for melt processing without any degradation. The UV absorption intensities decreased with increased irradiation time, indicating that photocrosslinking occurred.     

含X-型二维液晶基元和顺式-4,4′-双(4-羟基苯基偶氮)二苯并-18-冠-6冠醚环液晶共聚酯的合成与表征

以4,4-′(α,ω-辛二酰氧)二苯甲酰氯(M1)、2,5-双[4-′(对癸氧基苯基)苯甲酰氧基]对苯二酚(M2)和顺式-4,4′-双(4-羟基苯基偶氮)二苯并-18-冠-6(M3)为单体,通过溶液共缩聚反应,合成了一系列新的含X-型二维液晶基元和顺式-4,4′-双(4-羟基苯基偶氮)二苯并-18-冠-6冠醚环的主链型液晶共聚酯.单体1(M1)由对羟基苯甲酸和辛二酰氯,通过酯化和取代反应制备,单体2(M2)由2,5-二羟基苯醌和对癸氧基苯基苯甲酰氯通过酯化和还原反应制备,单体3(M3)由顺式-二氨基二苯并-18-冠-6和苯酚通过重氮化和偶联反应制备.共聚酯的分子量不高,[η]在0.30~0.39之间.单体的化学结构通过IR、UV1、H-NMR、MS和元素分析等方法确证.共聚酯的外观为黄色粉状固体,除共聚酯CP9外,室温下不溶于CHCl3和THF溶剂.共聚酯的性质采用GPC、[η]、DSC、TG、WAXD和POM等方法进行了研究,发现所有的共聚酯加热到各自的熔融温度以上都能形成液晶态,在液晶态可以观察到近晶相和向列相的典型织构.共聚酯的熔融温度(Tm)和各向同性温度(Ti)随共聚酯分子中顺式-4,4′-双(4-羟基苯基偶氮)二苯并-18-冠-6用量的改变呈规律性变化.WAXD研究进一步证实了共聚酯的液晶性.     

Carbohydrate‐based copolyesters made from bicyclic acetalized galactaric acid

Mixtures of the dimethyl esters of adipic acid and 2,3:4,5‐di‐O‐methylene‐galactaric acid (Galx) were made to react in the melt with either 1,6‐hexanediol or 1,12‐dodecanediol to produce linear polycyclic copolyesters with aldarate unit contents varying from 10 up to 90 mole %. The copolyesters had weight–average molecular weights in the ～35,000–45,000 g mol^?1 range and a random microstructure, and were thermally stable up to nearly 300 °C. They displayed T_g in the ‐50 to ‐7 °C range with values largely increasing with the content in galactarate units. All the copolyesters were semicrystalline with T_m between 20 and 90 °C but only those made from 1,12‐dodecanediol were able to crystallize from the melt at a crystallization rate that decreased as the contents in the two comonomers approached each other. Copolyesters containing minor amounts of galactarate units adopted the crystal structure characteristic of aliphatic polyesters but a new crystal polymorph was formed when the cyclic sugar units became the majority. Stress–strain parameters were sensitively affected by composition of the copolyesters with the mechanical behavior changing from flexible/ductile to stiff/brittle with the replacement of adipate units by the galactarate units. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

ABA triblock copolyesters composed of poly(l-lactide) A hard blocks: A comparative study of amorphous and crystalline aliphatic polyesters as B soft blocks

In this article, two series of ABA triblock copolyesters composed of poly(l-lactide) A hard blocks and odd-odd aliphatic polyesters as B soft midblock were prepared and compared by various techniques. The results showed that the block structures could be formed without any detectable transesterification, and the composition and molecular weight of the triblock copolyesters could be well controlled by adjusting the feeding ratio of l-lactide monomer to the polyester macroinitiator. It was found that the thermal properties, crystal structure, and spherulitic morphology of the triblock copolyesters depended on the composition and block length. The impact of amorphous and crystalline midblocks on the mechanical properties was compared and discussed. The triblock copolyesters composed of crystalline midblock showed similar ultimate stress and elongation, but higher tensile modulus and yield stress, in comparison with analogous containing amorphous midblock. The triblock copolyester composed of short PLLA hard block and amorphous aliphatic polyester soft midblock displayed typical elastomeric behavior without yield, which is a promising aliphatic polyester thermoplastic elastomer.     

Syntheses and Physical Characterization of Biodegradable Poly(butylene succinate-co-butylene itaconate) Copolymers

Biodegradable aliphatic poly (butylene succinate-co-butylene itaconate) (PBSBIs) from succinic acid, itaconic acid and 1,4-butanediol were synthesized through a polycondensation with titanium tetraisoproxide (TTP), diphenylphosphinic acid (DPPA) as the novel co-catalysts in this article. By means of gel permeation chromatography (GPC) and nuclear magnetic resonance spectrometer (NMR), it was revealed that the PBSI copolyesters had number average molecular weights M_n higher than 3.0 × 10⁴, and the composition of copolyesters was in good agreement with that expected from the feed composition of the reactants. With respect to thermal properties, melting temperature (T_m), crystallization temperature (T_c), and crystallinity (X_c) were found to decrease with increasing the BI/BS unit molar ratio up to 0.67. X-ray diffraction patterns indicated that the PBSIs copolyesters had the same crystal structure as the PBS. While increasing the BI/BS unit molar ratio up to 1, the copolyesters would change into insolubility and inmelt crosslinked elastomer. Otherwise, the observation of polarizing optical microscope (POM) showed that the spherulite size of copolyesters gradually became smaller with the increasing of BI unit content. Experimental results also showed that the contents of itaconic acid had an important effect on the biodegradable performance of copolyesters.