PPS／PES共混体系热行为特征的研究

本文借用TBA、DSC技术,研究了聚苯硫醚(PPS)与聚醚矾(PES)共混的相容性,讨论了共混方法对两者相容性的影响,研究了无定形的聚醚矾对半结晶性的聚苯硫醚熔融、结晶和冷结晶行为的影响以及PPS/PES共混物的界面行为。结果表明:溶液共混较机械共混相容性好;且在PES含量为60～70％(重量百分比)时,两组份相容性得到提高并存在较强的界面效应,在DSC谱图上呈现界面相的玻璃化转变;PFS的加入,破坏了PPS原有的结晶聚集态结构,使PPS的熔融双峰变为单峰,并促进了PPS的冷结晶。     

多次DSC扫描对聚苯硫醚/尼龙6共混物中聚苯硫醚组分结晶行为的影响

用DSC研究了多次重复扫描对聚苯硫醚/尼龙 6(PPS/PA6)共混物中PPS组分结晶行为的影响.随扫描次数增加,熔融温度低时,PPS的结晶温度稍有提高;熔融温度高时,PPS的结晶温度逐步降低;而且出现2或3个结晶峰.共混物中PPS组分除结晶温度比纯PPS的高外,随熔融温度和扫描次数增加,仅有单一高温结晶峰 .以上结果可用自成核、异相成核和交联作用来解释.     

PPS/PES共混物及其碳纤维复合材料内耗行为的研究

本工作利用内耗测量方法研究了PPS/PES共混物及其碳纤维复合材料的相容性以及多重转变和松弛行为,结果表明:(1)PPS与PES存在分子运动水平上的相互作用,共混组份比是决定其相互作用程度的重要因素;(2)PPS/PES共混物及其碳纤维复合材料中的PES相的β转变与松弛的时间存在较宽的连续分布,其分布宽度随共混组份比变化而变化,当PES相对含量为80%时,松弛时间分布宽度出现最大值;(3)PPS/PES共混物及其碳纤维复合材料处于热力学亚稳态,热处理增大了PPS与PES的相分离程度,减弱了它们之间的相互作用;(4)低温区热历史对PPS玻璃化转变有较大影响,内耗峰高及峰温随起始测量温度的升高而下降。     

聚苯硫醚/尼龙6共混物的结晶与熔融行为EI北大核心

用 DSC研究了不同组成比的聚苯硫醚 ( PPS) /尼龙 6( PA6)共混物中 PPS和 PA6组分的结晶与熔融行为及其相互作用的影响 ,结果表明 ,PPS在 PA6熔体存在下结晶温度明显提高 ,结晶峰形变窄 ;随 PA6含量增加 ,PPS的结晶温度移向高温 ,甚至 PPS成为分散相 ,这一作用还十分明显 ;而 PPS的熔融温度受共混影响较小 ,结晶了的PPS也使 PA6的结晶温度有所提高 ,但不如 PPS的结晶温度提高明显 ;当 PA6为分散相时 ,PA6的结晶温度才开始降低 ;随 PPS含量增加 ,PA6的起始熔融温度和熔点逐渐降低。     

热塑性树脂增韧聚苯硫醚的结晶行为

用DSC研究了高性能热塑性树脂聚砜(PSF)、酚酞型聚醚酮(PEK-C)与聚苯硫醚(PPS)共混物的结晶熔融行为,结果表明,PSF、PEK-C主要起阻碍PPS结晶的作用,使Avrami指数n值和冷却结晶函数m值下降;热塑性树脂的T_g越高和熔融温度提高,影响更大。     

聚苯硫醚/聚醚砜共混体系的织构和动态力学行为

本文用偏光显微镜(PLM)和动态扭辫分析(TBA)技术研究了各种组成比聚苯硫醚/聚醚砜(PPS/PES)共混体系的形态结构和动态力学行为。实验结果表明,PPS/PES 共混物是高性能的部分相容的微多相分散体系。PPS/PES共混体系的结构和动态力学行为随组成的变化而变化。      

PPS/PES共混物及其碳纤维增强复合材料的热行为特征的研究

应用广角X光散射(WAXS)和示差扫描量热分析(DSC)技术研究了聚苯硫醚/聚醚砜共混物及其碳纤维增强聚苯硫醚/聚醚砜混杂基体复合材料的结构特征和熔融、结晶行为.实验结果表明,(1)聚醚砜和碳纤维的混入未使聚苯硫醚的晶型发生改变,但使聚苯硫醚的结晶规整度降低;(2)碳纤维的混入可引起聚苯硫醚熔点降低,而混入聚醚砜并不引起聚苯硫醚的熔点降低;(3)聚醚砜和碳纤维均对聚苯硫醚存在诱导结晶效应,当碳纤维和聚醚砜共存时,聚本硫醚倾向于在碳纤维表面择优成核结晶.      

间规聚苯乙烯/高抗冲聚苯乙烯(sPS/HIPS)共混物非等温结晶的晶型与熔融行为

本文采用熔融挤出共混法制备了间规聚苯乙烯/高抗冲聚苯乙烯（sPS/HIPS）共混物,并用差示扫描量热仪和X射线衍射仪研究了sPS及其共混物在不同的熔融温度和降温速率下的非等温结晶的晶型与熔融行为.研究结果表明,熔融温度的提高使sPS及其共混物的结晶温度降低,并有利于β晶的形成.sPS的晶型取决于sPS降温结晶的温度.HIPS的加入使sPS降温结晶的温度提高时,有利于形成α晶;反之有利于形成β晶.降温速率提高有利于形成α晶.     

FEP/PPS共混涂层的热学行为及相结构分析

采用差示扫描量热法(DSC)及热重分析法(TG)研究了聚全氟乙丙烯/聚苯硫醚(FEP/PPS)共混涂层的热学行为,用X射线衍射仪(XRD)测定了其相结构。结果表明,FEP/PPS为一不相容共混体系,在分子水平上是不相容的。在惰性气氛中,FEP/PPS共混涂层在380℃以前热稳定性良好,其热分解包含两个阶段,先是FEP的分解,后是PPS的分解,且第二阶段失重率和测试终止残重随PPS的增加而增加。相分析表明,FEP/PPS共混涂层由晶相及非晶FEP、晶相及非晶PPS和晶相TiO2组成,涂层中PPS的结晶度与涂料粉末相比有大幅降低,是由于涂层制备过程对PPS熔融结晶行为的影响所致。     

熔融温度对PPS／PEEK中PPS的结晶熔融行为的影响

用粉末干混法制备结晶／结晶共混体系ＰＰＳ／ＰＥＥＫ，并用ＤＳＣ研究了不同熔融温度下淬火ＰＰＳ及ＰＰＳ／ＰＥＥＫ共混物中ＰＰＳ的结晶熔融行为。熔融温度（Ｔｍｅｌｔ）高于３６０℃时，对ＰＰＳ的结晶熔融行为有影响，结晶温宽（ΔＴｃ）随Ｔｍｅｌｔ提高而加宽；ＰＥＥＫ加入ＰＥＥＫ含量增加，使ＰＰＳ的结晶、熔融温度下降。共混物中的ＰＰＳ的结晶熔融行为受Ｔｍｅｌｔ影响更大。     

聚苯硫醚/尼龙6共混物的结晶与熔融行为

用ＤＳＣ研究了不同组成比的聚苯硫醚（ＰＰＳ）／尼龙６（ＰＡ６）共混物中ＰＰＳ和ＰＡ６组分的结晶与熔融行为及其相互作用的影响,结果表明,ＰＰＳ在ＰＡ６熔体存在下结晶温度明显提高,结晶峰形变窄;随ＰＡ６含量增加,ＰＰＳ的结晶温度移向高温,甚至ＰＰＳ成为分散相,这一作用还十分明显;而ＰＰＳ的熔融温度受共混影响较小,结晶了的ＰＰＳ也使ＰＡ６的结晶温度有所提高,但不如ＰＰＳ的结晶温度提高明显;当ＰＡ６为分散     

PPS／PBT共混体系的研究

在Ｂｒａｂｅｎｄｅｒ混合仪中，用熔融混合法制备结晶／结晶共混体系ＰＢＴ／ＰＰＳ。采用ＤＳＣ、ＷＡＸＤ和ＳＥＭ对共混物的结晶，熔融，相容性和形态进行了研究。结果表明，ＰＢＴ／ＰＰＳ共混物是不相容的，各自自己的微区内进行结晶。ＰＢＴ加入可使窝本粘度明显上升。     

Crystallization of polyphenylene sulfide

The properties of molded PPS parts are dependent on the crystalline morphology developed during processing. Even though processed under identical conditions, the crystalline morphology may differ owing to the differences in the crystallization process. The crystallization behaviour of a polymer is known to depend on its molecular architecture which in turn depends upon polymerization process. Thus the study of the crystallization behaviour of polymer with reference to its molecular architecture is essential for obtaining product with desirable properties. In the present paper, the crystallization behaviour of two grades of polyphenylene sulfide was investigated using differential scanning calorimetry (DSC). An attempt has been made to explain the differences in the crystallization behaviour of PPS samples on the basis of the differences in their molecular architecture. The structural differences of PPS manifest themselves in terms of the depression in the equilibrium melting point, retardation of nucleation and overall crystallization rate and coarsening of spherulitic texture.     

新型聚苯硫醚复合涂层的制备和性能研究

用浸涂法制备了G/MoS2/Ekonol/PES/PPS多元复合涂层,以涂层结合强度为评价标准,采用混料回归实验优化设计了G/MoS2/Ekonol/PES/PPS复合涂层的涂料配方,用拉开法测定复合涂层的结合强度,并对结合表面进行了观察和分析,研究了涂料组成、涂层制备工艺参数和涂层厚度对涂层结合强度的影响。结果表明,用浸涂法能制得力学性能优良的G/MoS2/Ekonol/PES/PPS复合涂层;采用典型配方Ekonol:PES:PPS:G/MoS2:助剂=25:20:45:8:2(质量比)能够得到较大的结合强度。     

Preparation and properties of poly (p-phenylene sulfide)/multiwall carbon nanotube composites obtained by melt compounding

In this paper, electrical and mechanical properties of Poly (p-phenylene sulfide) (PPS)/multi-wall carbon nanotubes (MWNTs) nanocomposites were reported. The composites were obtained just by simply melt mixing PPS with raw MWNTs without any pre-treatment. The dispersion of MWNTs and interfacial interaction were investigated through SEM &TEM and Raman spectra. The rheological test and crystallization behavior were also investigated to study the effects of MWNTs concentration on the structure and chain mobility of the prepared composites. Though raw MWNTs without any pre-treatment were used, a good dispersion and interaction between PPS and MWNTs have been evidenced, resulting in a great improvement of electrical properties and mechanical properties of the composites. Raman spectra showed a remarkable decrease of G band intensity and a shift of D bond, demonstrating a strong filler–matrix interaction, which was considered as due to π–π stacking between PPS and MWNTs. The storage modulus (G′) versus frequency curve presented a plateau above the percolation threshold of about 2–3 wt% with the formation of an interconnected nanotube structure, indicative of ‘pseudo-solid-like’ behavior. Meanwhile, a conductive percolation threshold of 5 wt% was achieved and the conductivity of nanocomposites increased sharply by several orders of magnitude. The difference between electrical and rheological percolation threshold, and the effect of critical percolation on the chain mobility, especially on crystallization behavior of PPS, were discussed. In summary, our work provides a simple and fast way to prepare PPS/MWNTs nanocomposites with good dispersion and improved properties.     

聚苯硫醚共混物非等温结晶动力学研究

酚酞型聚醚酮可显著改善聚苯硫醚的冲击韧性，本工作运用差示量热扫描技术（ＤＳＣ），研究了聚苯硫醚及聚苯硫醚／酚酞型聚醚酮共混物的非等温结晶动力学，定量计算了有关参量。结果表明，含１０％（质量）酚酞型聚醚酮的聚苯硫醚具有最高的结晶能力，据此探讨了酚酞型聚醚酮对聚苯硫醚结晶行为的影响。