半芳香族耐高温尼龙PA6T/10T的合成及应用

利用癸二胺,己二胺和对苯二甲酸为聚合单体,以去离子水为溶剂,通过预聚合/固相增黏的工艺合成了半芳香族耐高温尼龙聚对苯二甲酰己/癸二胺(PA6T/10T)。采用傅里叶变换红外光谱、核磁共振碳谱对合成的PA6T/10T树脂进行了结构表征,并研究了PA6T/10T和聚(对苯二甲酰/己二酰)己二胺(PA6T/66)的熔点和结晶温度以及玻璃纤维(GF)增强改性PA6T/10T和PA6T/66的热失重行为、力学性能及耐热氧老化性能。结果表明,与传统的PA6T/66相比,合成的PA6T/10T结晶温度提升5℃,结晶半峰宽缩短了10.6℃,结晶速率明显提升;与GF增强PA6T/66相比,GF增强PA6T/10T的力学性能无显著差异,其初始分解温度提高16℃,热稳定性明显改善;GF增强PA6T/10T与GF增强PA6T/66的初始反射率及亨特白度相近,但经180℃热氧老化3h和表面贴装无铅回流焊接机过炉老化3次后,前者的反射率和白度均明显高于后者,表明GF增强PA6T/10T具有更好的耐热氧老化性能和耐黄变性能。     

聚对苯二甲酰十碳二胺的制备和热稳定性研究

以对苯二甲酸和癸二胺为原料,经成盐、预聚合和固相聚合三个步骤合成了新型长碳链和较高分子量的半芳香尼龙聚对苯二甲酰十碳二胺（PA10T）。用TG-DTG方法研究了PA10T的热降解和热降解动力学,结果表明,PAIOT的热分解为一步降解,其起始平衡降解温度为435．3℃,终止平衡降解温度为470．7℃,最大降解速率时平衡降解温度为459．5℃。通过微分法和积分法计算出PA10T的热分解活化能分别为274．4kJmol^-1和263．96～290．37kJmol^-1之间,其耐热性能优于脂肪族尼龙。     

无卤阻燃PA10T力学性能及热稳定性研究

采用一种次膦酸金属盐阻燃剂(FR-Phosphite)对聚对苯二甲酰癸二胺(PA10T)进行阻燃改性。研究了阻燃剂含量对改性PA10T力学性能的影响,并分析了不同阻燃剂含量时阻燃PA10T的热降解行为。结果表明,随着阻燃剂含量的增加,阻燃PA10T材料的拉伸强度呈现先上升后下降的趋势;阻燃剂FR-Phosphite降低了PA10T的初始降解温度。     

半芳香族耐高温PA10T/1010的非等温结晶动力学研究

利用对苯二甲酸、癸二胺、癸二酸合成了聚对苯二甲酰癸二胺(PA10T)和聚酰胺(PA)1010的共聚物PA10T/1010,通过差示扫描量热法研究了PA10T/1010的非等温结晶动力学,结果表明随着降温速率的增加,结晶温度和熔点不断降低,同时结晶温度的范围变宽,结晶所需时间减少。用Jeziorny法描述了PA10T/1010的非等温结晶过程,发现其结晶过程分为两段,晶体生长方式在前期为二维盘状生长,后期为多维生长。通过Mo法描述了PA10T/1010的非等温结晶动力学,发现降温速率越大,在单位时间内PA10T/1010所能达到的相对结晶度越高。最后通过Kissinger方法计算得到PA10T/1010非等温结晶活化能为–171.47 k J/mol。     

耐高温PA6T共聚物的合成与表征

采用预聚+固相增黏的方法合成了聚对苯二甲酰己二胺(PA6T)的共聚物,研究了预聚温度和压力以及排水量对预聚物端基和颜色的影响,确定最佳的预聚条件为:预聚温度240℃,最终预聚物含水量为22.7%;确定了最佳的固相增黏条件为:增黏温度240℃,氮气流量0.20 mL/min。采用傅立叶变换红外光谱和1H NMR表征了预聚物和聚合物的结构。研究了PA6T/66、PA6T/66/6和PA6T/6共聚体系的热力学性质,发现相对于PA66盐,己内酰胺的共聚能更大程度地降低聚合物的熔点和结晶温度;研究了DSC测试过程中预聚物的增黏行为,发现预聚物在第一次升温过程中已经完成了增黏;研究了预聚物和聚合物的热失重,发现二者曲线的差别来源于预聚物在升温增黏过程中释放的小分子。     

半芳香族耐高温聚酰胺（PA6T/10T/66）的制备及性能研究

二元共聚半芳香聚酰胺（PA6T/66）是一种低成本、高刚性、工艺较成熟的高分子材料，但韧性较差，具有一定的吸水率。文章在PA6T/66树脂中引入低吸水率脂肪族长碳链耐高温聚对苯二甲酰癸二胺（PA10T）链段，利用熔融聚合与微负压增黏相结合的方式制备PA6T/10T/66树脂。结果表明：制备PA6T/10T/66树脂时，PA10T盐最优加入量为5%。红外光谱表征PA6T/10T/66(45/5/50)树脂已完全聚合。差示扫描量热仪（DSC）测试PA6T/10T/66(45/5/50)树脂熔点为300℃。树脂黏度为2.5时，其拉伸强度达到50 MPa，弯曲强度为54 MPa。当聚合压力为2.35 MPa，封端剂用量占总盐质量为1.5%时，树脂黏度符合使用要求。此工艺成本低、制备过程简单，得到的三元共聚树脂适合玻纤改性、配色、注塑等应用。     

半芳香族耐热性共聚酰胺的合成及性能

以癸二胺、己二胺和对苯二甲酸为主要原料,通过一步熔融缩聚法合成了半芳香族共聚酰胺聚对苯二甲酰癸二胺/己二胺(PA10T/6T),采用核磁共振碳谱确认了其结构。在此基础上,通过差示扫描量热仪、X射线衍射仪和热重分析仪对其熔融温度、结晶温度、晶体生长方式、结晶活化能、结晶度以及热稳定性进行了测试分析研究。结果显示,PA10T/6T具有较宽的加工窗口,当PA6T链段的物质的量分数达到10%,30%和50%时,PA10T/6T熔融温度较PA10T分别下降了10.97,37.41,7.8℃;PA6T链段的引入并没有改变聚合物的晶体生长方式且对聚合物的热稳定性没有明显影响;随着PA6T链段含量的增加,聚合物的结晶温度、熔融温度、结晶活化能的绝对值以及结晶度均呈先降低后升高的趋势,这是聚合物分子链结构和聚合物晶体完整性综合影响的结果。     

聚对苯二甲酰癸二胺导热复合材料性能的研究

通过双螺杆挤出机制备出石墨/聚对苯二甲酰癸二胺(PA10T)和石墨烯/PA10T导热复合材料,研究了石墨和石墨烯对复合材料力学性能和导热性能的影响。研究发现:导热复合材料的拉伸强度和悬臂梁缺口冲击强度随着导热填料含量的增加呈现先增大后减小的变化,而弯曲模量和导热系数随导热填料含量的增加而增加。与石墨相比,添加更少量的石墨烯即可以显著提高复合材料的力学性能和导热性能。     

耐高温PA10T/11共聚尼龙的合成与表征

以癸二胺、对苯二甲酸和氨基十一酸为单体,水为溶剂,通过高温熔融缩聚合成了PA10T/11共聚尼龙.采用特性黏度测试、傅里叶红外光谱、差示扫描量热法和热重分析对产物的结构和热性能进行了表征.结果表明:PA10T/11共聚尼龙的耐高温性能优秀,PA10T盐质量分数为70％时,PA10T/11共聚尼龙的起始分解温度为385.2℃,热分解温度(Td)为439.2 ℃,熔点(Tm)为281.64 ℃.PA10T/11共聚尼龙在保证耐高温性能的同时,有效地降低了熔点.     

半芳香族耐高温尼龙PA12T的合成、表征与性能

利用1,12–十二烷二胺和对苯二甲酸为聚合单体,以去离子水为溶剂,通过预聚合加固相增黏的工艺合成了半芳香族耐高温尼龙聚对苯二甲酰十二烷二胺(PA12T)。分析了影响聚合反应的主要因素,从而确定最优的工艺条件。采用傅立叶变换红外光谱,核磁共振1H谱、13C谱、1H–13C的异核单量子相关谱对所合成的PA12T进行了结构表征,并研究了PA12T的熔点和结晶温度、热失重行为、毛细管流动性和力学性能。结果表明,合成的PA12T具有良好的耐热性能和力学性能,合成方法为PA12T的工业化生产提供了参考。     

Solid‐state polymerization and characterization of a copolyamide based on adipic acid, 1,4‐butanediamine,and 2,5‐furandicarboxylic acid

2,5‐Furandicarboxylic acid (FDCA) is a promising biobased alternative material to terephthalic acid. In this study, three types of poly(butylene adipamide) (PA‐4,6) containing 10, 20, and 30 mol % of poly(butylene‐2,5‐furandicarboxylamide) (PA‐4,F) were synthesized through consecutive prepolymerization and solid‐state polymerization (SSP). The incorporation of a 10 mol % PA‐4,F component into PA‐4,6 resulted in slight increases in the intrinsic viscosity (IV) and glass‐transition temperature (T_g) after 12 h of SSP at 220 °C. When the SSP temperature and reaction time increased, IV increased proportionally. The highest IV value of 0.75 was obtained by 48 h of SSP at 240 °C, whereas increases in the PA‐4,F content to 20 and 30 mol % gave rise to decreases in IV, T_g, and melting temperature; this interrupted the increase in SSP temperature. The thermal decomposition temperature of the PA‐4,F‐incorporated polyamide was lower than that with PA‐4,6 because of the lower thermal stability of the FDCA component. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43391.     

固体超强酸催化PLA-PEG嵌段共聚物的合成

采用开环聚合法,固体超强酸SO42-/ZrO2-CeO2为催化剂,催化丙交酯和聚乙二醇合成PLA-PEG嵌段共聚物,研究了聚乙二醇(PEG)分子量、反应时间、温度、催化剂用量等条件对共聚物的影响,并通过红外光谱、Hammett指示剂法及NH3-TPD等方法对固体超强酸的酸性质进行了表征。结果表明,当焙烧温度为650℃时,得到的固体超强酸SO24-/ZrO2-CeO2酸强度与酸量最大,用该催化剂催化合成PLA-PEG嵌段共聚物,当PEG分子量为6 000,反应时间9 h、反应温度170℃,催化剂用量为丙交酯质量分数的1.0%时,得到PLA-PEG共聚物的特性粘数最大,为1.693 g/dL。     

阻燃型玻纤增强PA10T复合材料的热氧老化性能

采用溴化环氧树脂对聚对苯二甲酰葵二胺(PA10T)进行改性,并通过熔融共混法制备阻燃型玻璃纤维(GF)增强PA10T复合材料,采用人工加速热氧老化手段,研究了热氧老化对其力学性能的影响,并用扫描电子显微镜(SEM)对复合材料的冲击断面形貌进行观察。结果表明,随热氧老化时间增加,复合材料的拉伸强度、弯曲强度和缺口冲击强度均下降明显,分子链松弛过程减弱;老化10 d后,复合材料的弯曲弹性模量仅略有下降而储能模量达到最大值,表明在热氧老化初期PA10T分子链之间发生了微交联,但随老化时间继续增加,两者均下降明显。SEM结果表明GF与树脂基体之间界面粘接作用的强弱是影响材料热氧老化性能变化的主要因素。     

Compatibilization of polypropylene/nylon 6 blends with a polypropylene solid‐phase graft

The compatibilization of polypropylene (PP)/nylon 6 (PA6) blends with a new PP solid‐phase graft copolymer (gPP) was systematically studied. gPP improved the compatibility of PP/PA6 blends efficiently. Because of the reaction between the reactive groups of gPP and the NH₂ end groups of PA6, a PP‐g‐PA6 copolymer was formed as a compatibilizer in the vicinity of the interfaces during the melting extrusion of gPP and PA6. The tensile strength and impact strength of the compatibilized PP/PA6 blends obviously increased in comparison with those of the PP/PA6 mechanical blends, and the amount of gPP and the content of the third monomer during the preparation of gPP affected the mechanical properties of the compatibilized blends. Scanning electron microscopy and transmission electron microscopy indicated that the particle sizes of the dispersed phases of the compatibilized PP/PA6 blends became smaller and that the interfaces became more indistinct in comparison with the mechanical blends. The microcrystal size of PA6 and the crystallinity of the two components of the PP/PA6 blends decreased after compatibilization with gPP. The compatibilized PP/PA6 blends possessed higher pseudoplasticity, melt viscosity, and flow activation energy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 420–427, 2004     

20kt/a PA6前聚合工艺的优化

介绍了20kt/aPA6聚合装置前聚合器的结构及工艺特点;分析了生产中前聚合工艺存在的问题,提出了解决措施;验证了前聚合器结构的设计参数。指出生产中由于前聚合器底部出料温度波动大,波动值达±8.08℃,影响了PA6切片的可纺性。通过降低前聚合反应的压力及加热联苯炉的温度,调整前聚合器顶部冷凝器的排汽温度,前聚合器底部出料温度的波动值可控制在±2.5℃,有效提高了PA6切片的质量。     

聚乳酸及其共聚物合成技术进展

介绍了聚乳酸及其共聚物的合成方法；讨论了直接缩聚法、开环聚合法和直接-固相聚合法制备聚乳酸及其共聚物的工艺条件与催化体系。     

Synthesis and characterization of high strength polyimide/silicon nitride nanocomposites with enhanced thermal and hydrophobic properties

Polyimide (PI) composite films were synthesized incorporating amino modified silicon nitride (Si3N4) nanoparticles into PI matrix via in situ polymerization technique. The mechanical and thermal perfor-mances as well as the hydrophobic properties of the as prepared composite films were investigated with respect to the dosage of the filler in the PI matrix. According to Thermogravimetric (TGA) analysis, mean-ingful improvements were achieved in T5 (5％weight loss temperature) and T10 (10％weight loss temper-ature) up to 54.1 ℃ and 52.4 ℃, respectively when amino functionalized nano-Si3N4 particles were introduced into the PI matrix. The differential scanning calorimetry (DSC) results revealed that the glass transition temperature (Tg) of the composites was considerably enhanced up to 49.7 ℃ when amino func-tionalized Si3N4 nanoparticles were incorporated in the PI matrix. Compared to the neat PI, the PI/Si3N4 nanocomposites exhibited very high improvement in the tensile strength as well as Young's modulus up to 105.4％ and 138.3％, respectively. Compared to the neat PI, the composites demonstrated highly decreased water absorption behavior which showed about 68.1％ enhancement as the content of the nanoparticles was increased to 10 wt％. The SEM (Scanning electron microscope) images confirmed that the enhanced thermal, mechanical and water proof properties are essentially attributed to the improved compatibility of the filler with the matrix and hence, enhanced distribution inside the matrix because of the amino groups on the surface of Si3N4 nanoparticles obtained from surface functionalization.