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 共查询到19条相似文献,搜索用时 171 毫秒
1.
王勇  吴大诚 《应用化学》1994,11(5):95-97
采用差示扫描量热仪和热台偏光显微镜研究了对羟基苯甲酸(PHB)/聚对苯二甲酸丁二酯(PBT)共聚酯的热转变行为和液晶性。结果表明,PHB/PBT共聚酯呈现多重相转变特征,这与共聚酯中存在不同程度的PBT富微区和PHB富微区有关;当PHB链节含量在20%~80%范围时,共聚酯均呈现向列型液晶特征.  相似文献   

2.
PET/PA66/液晶共聚酯酰胺共混体系的流变性能   总被引:5,自引:0,他引:5  
采用SEM1、热偏光显微研究了聚对苯二甲乙二酯(PET)/聚酰胺66(PA66)/热致液晶共聚酯酰胺(LC30)三元共混物的形态结构;利用Instron3211型毛细管流变仪研究了共混物的流变性能,结果表明:PET/PA66/LC30共混物为一热力学不相容的多相聚合物体系,LC30的加入提高了PET/PA66的相容性,有效地改善了PET/PA66共混物的流变性能,PET/PA66/LC30三元共混  相似文献   

3.
聚酯酰胺的合成及表征   总被引:1,自引:0,他引:1  
用两种方法合成了聚酯酰胺(PEA)共聚物.一种是两步法,即先合成对苯二甲酸乙醇酰胺(BAET)单体,然后与对苯二甲酸乙二酯(BHET)共缩聚;另一种是一步法.即在酯交换反应中直接添加乙醇胺(EA).两种方法制得的聚酯酰胺(PEA)共聚物测试证明了为产物,并分析了合成中的化学反应.  相似文献   

4.
聚酯酰胺的合成及表征   总被引:2,自引:0,他引:2  
 用两种方法合成了聚酯酰胺(PEA)共聚物.一种是两步法,即先合成对苯二甲酸乙醇酰胺(BAET)单体,然后与对苯二甲酸乙二酯(BHET)共缩聚;另一种是一步法.即在酯交换反应中直接添加乙醇胺(EA).两种方法制得的聚酯酰胺(PEA)共聚物测试证明了为产物,并分析了合成中的化学反应.  相似文献   

5.
采用DCS、POM、SEM及力学性能测试,研究了不同对羟基苯甲醛和对苯二甲酸乙二醇酯含量的液晶共聚酯PET40/PHB60(LCP1)和PET30/PHB70(LCP2)的共混物与尼龙1010为基体的三元混体系。结果表明,液晶共混物的力学性能比单组分有明显提高,通过改变混合液晶中两组分的含量可调节其加工温度与粘度,从而满足了与尼龙1010共混的加工窗口要求。混合液晶的加入对尼龙1010的结晶与熔融  相似文献   

6.
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。  相似文献   

7.
用广角X-角线衍射法和差法扫描量热法研究了磷酸三苯酯对PBT/PET共混体系结晶行为影响,结果表明:TPPW作为该共混体系的稳定剂,只能延长在熔融状态下酯交换反应发生的时间,TPP含量一定时,熔融时间增加,PBT,PET之间的酯交换反应同样会发生,不同熔融时间,就要求TPP的用量也不相同。TPP在PBT/PET共混体系中没有结晶成核剂的作用,它也不改变PBT,PET的结晶结构。  相似文献   

8.
采用直接熔融缩聚及固相聚合方法由4,4’-二羟基二苯酮(BHP),对苯二甲酸(TPA),对羟基苯甲酸(PHBA),间苯二酚(RES)成功地合成了四元共聚酯高分子,该聚酯的组成结构及性质由偏光显微镜、广角X-射线衍射、DSC等手段进行表征,结果表明共聚酯具有向列型液晶特征。  相似文献   

9.
液晶嵌段共聚物PET/60PHB-b-PC的合成及结构与性能   总被引:1,自引:0,他引:1  
采用PET齐聚物的原位乙酰化法通过加入少量乙二醇(EG)合成了端羟基液晶聚合物PET/60PHB,并将其作为大单体,与双酚A及碳酸二苯酯通过熔融酯交换法,进一步制得了液晶嵌段共聚物PET/60PHB b PC.研究了合成规律,并借助粘度测定、DSC、偏光显微镜、X 光衍射和红外光谱分析等手段对合成的液晶嵌段共聚物进行了表征.研究表明,当PET齐聚物的ηinh=005~007dL/g,Ac2O/PHB(mol/mol)=13,EG/PET(mol/mol)=006时能获得颜色、液晶性、溶解性均很好的端羟基液晶聚合物PET/60PHB,以此液晶聚合物为原料,采用合适的配方与工艺,能获得粘度较高、液晶性较好,并且熔体流动性很好的液晶嵌段共聚物PET/60PHB b PC.通过偏光显微镜与X 光衍射观察,证明此嵌段共聚物呈现向列型液晶织构,但其液晶态织构与纯PET/60PHB、PET/60PHB和PC的混合物明显不同.此外,还初步建立了用红外的分析手段鉴定液晶聚合物PET/60PHB端基的方法.  相似文献   

10.
液晶共聚物与PSF原位复合的界面研究   总被引:3,自引:0,他引:3  
合成了两种热致性液晶共聚酯BP—LCP和SDP—LCP,对其熔融指数、取向性作了考察。选用基体聚砜(PSF)与液晶共聚酯进行熔融共混,得原位复合材料。SEM断口形态显示了两种液晶在基体中不同的成纤性,并显示出两相的不相容性。采用FT—IR方法分析了液晶共聚酯与PSF界面间的分子相互作用。进一步研究发现在PSF/BP-LCP原位复合体系中加入含PSF和BP-LCP的嵌段共聚物,其相容性得以改善  相似文献   

11.
通过熔融共混的方式,将实验室自行设计合成的三元共聚热致液晶聚酯酰亚胺(PPDI)与聚对苯二甲酸乙二酯(PET)进行共混,制备一系列不同液晶聚合物含量的共混体系.采用示差扫描量热仪(DSC)、广角X-射线衍射仪(WAXD)和动态力学性能分析仪(DMA)对共混体系的结构与性能进行表征.结果表明,共混体系中两组份之间具有良好...  相似文献   

12.
Acrylic acid has been grafted to polyethylene terephthalate (PET) by mutual irradiation, and the resulting copolymers converted to their sodium, calcium and lead salts. The electrical surface resistance of PET was reduced by grafting, the effect being most pronounced for the copolymer in the form of its sodium salt. The thermal stability of PET was studied by thermogravimetric analysis and differential thermal analysis, and activation energies were derived for the thermal decompositions; similar studies were made for the acidic and ionomeric copolymers. The stability of acidic copolymer was found to be lower than that of ungrafted PET; enhanced thermal stability was obtained only in the metallated copolymers.  相似文献   

13.
通过原子转移自由基聚合合成了线形及三臂聚苯乙烯-b-聚2(5)-乙烯基对(间)苯二甲酸二钠嵌段共聚物,通过凝胶渗透色谱、核磁共振和热失重表征证实得到了结构明确、分散度较窄的嵌段共聚物成核剂.采用熔融共混的方法制得聚对苯二甲酸乙二酯(PET)与成核剂共混样品.采用差示扫描量热仪与一维X射线衍射仪研究了PET及添加成核剂后...  相似文献   

14.
ABA‐type triblock copolymers and AB‐type star diblock copolymers with poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] hard outer segments and poly(n‐butyl vinyl ether) [poly(NBVE)] soft inner segments were synthesized by sequential living cationic copolymerization. Although both the two polymer segments were composed solely of poly(vinyl ether) backbones and hydrocarbon side chains, they were segregated into microphase‐separated structure, so that the block copolymers formed thermoplastic elastomers. Both the ABA‐type triblock copolymers and the AB‐type star diblock copolymers exhibited rubber elasticity over wide temperature range. For example, the ABA‐type triblock copolymers showed rubber elasticity from about ?53 °C to about 165 °C and the AB‐type star diblock copolymer did from about ?47 °C to 183 °C with a similar composition of poly(2‐AdVE) and poly(NBVE) segments in the dynamic mechanical analysis. The AB‐type star diblock copolymers exhibited higher tensile strength and elongation at break than the ABA‐type triblock copolymers. The thermal decomposition temperatures of both the block copolymers were as high as 321–331 °C, indicating their high thermal stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013  相似文献   

15.
液晶聚芳醚酮的结构与性能研究   总被引:1,自引:0,他引:1  
以联苯二酚、取代对苯二酚及含氟酮单体为原料 ,通过亲核取代反应 ,合成了系列具有液晶性的新型聚芳醚酮 .研究了聚合物分子结构与性能之间的关系 .由于结晶相是从有序的液晶相转化形成的 ,故侧基含量的增加对液晶聚合物的融熔转变温度无显著影响 .聚合物的液晶稳定性受侧基影响较大 ,含极性侧基的氯取代聚合物的液晶温区比含大空阻侧基的聚合物的液晶温区小得多 ,说明空间几何因素比极性因素对液晶稳定性的影响大 .不同分子量聚合物有不同的液晶有序结构 ,低分子量聚合物具有高有序液晶结构 ,而高分子量聚合物只有低有序的向列相结构 .  相似文献   

16.
Pentaerythritol/butane tetracarboxylic acid/polyethylene glycol (PBPEG) crosslinking copolymers as a novel solid-solid phase change material (SSPCM) were successfully synthesized through the reaction mechanism and conditions of hydroxyl-carboxyl condensation reaction. The composition and chemical structure, crystalline properties, phase change behaviors, thermal reliability and chemical stability of PBPEG crosslinking copolymers were investigated by Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WAXD), polarization optical microscopy (POM), differential scanning calorimetry (DSC), and thermogravimetry (TGA), respectively. The results show that PBPEG crosslinking copolymers have typical solid-solid phase transition temperatures in the range of 10.31~53.27°C and high latent heat enthalpy in the range of 89.6~102.8 J/g, the synthesized SSPCMs have good thermal reliability and chemical stability after 300 thermal cycles, and PBPEG crosslinking copolymers have good thermal stability before 364°C. In summary, the synthesized PBPEG crosslinking copolymers could be potentially used for thermal energy storage.  相似文献   

17.
新型侧链液晶M5MPP/MMEANB高聚物的合成与表征   总被引:1,自引:0,他引:1  
以4,4'-二羟基联苯、4-硝基苯胺、二溴己烷、甲基丙烯酸、氯代乙醇为原料合成了单体甲基丙烯酸[5(4'-甲氧基联苯4氧基)戊基]酯(M5MPP)、4-硝基偶氮苯基甲基-2-甲基丙烯酸酯基乙胺(MMEANB),并完成了单体的聚合和共聚,得到了含有非线性光学活性基团(NLO)的侧链液晶高分子,对其结构进行了表征.结果表明,均聚物PM5MPP及共聚物(M5MPP/MMEANB)属双向液晶高分子;PMMEANB属于非晶性高分子.证实了分子间吸电子与给电子基团相互作用有利于提高液晶高分子热稳定性,共聚物(M5MPP/MMEANB)具有较宽的液晶相温度范围.  相似文献   

18.
以生物基单体2,5-呋喃二甲酸、乙二醇为原料合成聚2,5-呋喃二甲酸乙二醇酯(PEF)。采用熔融酯交换法以PEF聚酯部分取代聚对苯二甲酸乙二醇酯(PET),制备了系列PET-b-PEF嵌段共聚酯。通过核磁共振仪(NMR)、差示扫描量热仪(DSC)、热失重仪(TGA)、X射线衍射仪(XRD)等技术手段表征了共聚酯的结构和性能。结果表明,该系列共聚酯的玻璃化转变温度(Tg)在75.8~80.3℃之间,且随着PEF链段质量分数的增加,PET-b-PEF嵌段共聚酯的Tg先降低后升高,结晶度和熔融温度逐渐降低。当PEF链段含量高于15%时,共聚酯没有结晶峰。该系列共聚酯具有良好的热稳定性,起始分解温度在392.2~407.9℃之间,与所制备的PET起始分解温度403.3℃接近。且当共聚酯中PEF链段含量低于15%时,起始分解温度均在407℃左右,优于PET的热稳定性。  相似文献   

19.

A series of copolyesters were synthesized by melt‐polycondensation reaction of poly(ethylene terephtalate) (PET) with various proportions of equimolar compositions of p‐acetoxybenzoic acid (p‐ABA), hydroquinone diacetate (HQDA) and terephtalic acid (TPA). Viscosity, liquid crystallinity, thermal properties, degree of crystallinity and thermal stabilitiy of these copolyesters were investigated by Ubbelohde viscometer, hot‐stage polarized light microscopy (PLM), differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD) and thermogravimetric analysis (TGA), respectively. On the basis of viscosity measurement, it was observed that intrinsic viscosity values of the copolyesters are increased regularly with increasing amounts of aromatic units (p‐ABA, HQDA and TPA) in the polymer chain. Thermotropic liquid crystalline behavior was observed in the copolyesters containing over 50 mol% of rigid p‐ABA/HQDA/TPA aromatic units. DSC analysis of the anisotropic copolyesters revealed broad and weak endotherms associated with the nematic phases, and the melting temperatures were found to be in the processable region. As the mol% of PET in the polymer chain increased, the specific enthalpies of fusion and the degree of crystallinity of the copolyesters were also increased regularly.  相似文献   

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