Modification of Interfacial Interaction of PBT/PP Blends by Adding Main-chain Liquid Crystalline Ionomer with Sulfonic Group

A main-chain liquid crystalline ionomer(MLCI)containing sulfonic group was synthesized by an interfacial condensation reaction.The MLCI was blended with polybutylene terephthalate(PBT)and polypropylene...     

侧链液晶离聚物对PA1010/PP共混体系的增容作用

将聚酰胺（PA1010）、聚丙烯（PP）和热致型侧链液晶离聚物（SLCI）进行熔融共混，采用FTIR，SEM，DSC，WAXD研究测定了共混物中的相互作用，用形态结构，热行为和结晶行为，系统地研究了SLCI对PA101／PP共混物的增容作用。结果表明，SLCI有效地改善了PA1010／PP共混物的形态结构，增强了PA1010与PP链间的相互作用，使PA1010／PP熔点升高，结晶度提高。     

Effect of a polyetheramine additive on the melt-flowability of poly(butylene terephthalate)

A polyetheramine (PEA) was added to poly(butylene terephthalate) (PBT) to improve its melt-flowability. Fourier transform infrared (FTIR) and solution proton nuclear magnetic resonance spectroscopy (¹H-NMR) were employed to check the change in chemical structure after compounding, while differential scanning calorimetry (DSC), wide angel X-ray diffraction (WAXD), capillary rheometer and a universal testing machine were used to investigate the thermal properties, crystal structure, rheological behavior and mechanical properties of PBT/PEA blends. The results revealed that a loading of 1.0wt% PEA in PBT drastically improved its melt-flowability without the loss of thermal properties and tensile strength. As comparisons, blends of PBT with polyols such as pentaerythritol and di(trimethylolpropane) were also prepared and the properties were evaluated. It was found that the melt-flowability improvement from these polyols was much lower than that from PEA.     

Preparation of core-shell structured polyacrylic modifiers and effects of the core-shell weight ratio on toughening of poly(butylene terephthalate)

Core-shell structured polyacrylic(named CSSP) impact modifiers consisting of a rubbery poly(n-butyl acrylate) core and a rigid poly(methyl methacrylate) shell with a size of about 353 nm were prepared by seed emulsion polymerization. The CSSP modifiers with different core-shell weight ratios(90/10, 85/15, 80/20, 75/25, 70/30, 65/35 and 60/40) were used to modify the toughness of poly(butylene terephthalate)(PBT) by melt blending. It was found that the polymerization had a very high instantaneous conversion(> 95.7%) and overall conversion(99.7%). The morphology of the core-shell structure was confirmed by means of transmission electron microscopy. Scanning electron microscopy was used to observe the morphology of the fractured surfaces. Differential scanning calorimeter was used to study the crystallization behaviors of PBT/CSSP blends. The dynamic mechanical analyses of PBT/CSSP blends showed two merged transition peaks of PBT matrix, with the presence of CSSP core-shell structured modifier, that were responsible for the improvement of PBT toughness. The results indicated that the notch impact strength of PBT/CSSP blends with a core-shell weight ratio of 75/25 was almost 8.64 times greater than that of pure PBT, and the mechanical properties agreed well with the SEM observation.     

高分子量聚对二氧环己酮改进聚DL-乳酸柔韧性的研究

为了提高DL-聚乳酸(PDLLA)的柔韧性,将10～20wt%不同比例的由本课题组自主合成的高分子量聚对二氧环己酮(PPDO)加入到PDLLA基体中,对共混物的微观两相形态、力学性能、热学性能和表面性质、降解性能等物化性质进行了研究.实验结果表明,PPDO加入后,在PDLLA/PPDO共混物的柔韧性得到显著提高的同时,共混物表面亲水性相应提高,降解速率也随之加快.     

Miscibility and properties of poly(l-lactic acid)/poly(butylene terephthalate) blends

Binary blends of poly(l-lactide) (PLLA) and poly(butylene terephthalate) (PBT) containing PLLA as major component were prepared by melt mixing. The two polymers are immiscible, but display compatibility, probably due to the establishment of interactions between the functional groups of the two polyesters upon melt mixing. Electron microscopy analysis revealed that in the blends containing up to 20% of poly(butylene terephthalate), PBT particles are finely dispersed within the PLLA matrix, with a good adhesion between the phases. The PLLA/PBT 60/40 blend presents a co-continuous multi-level morphology, where PLLA domains, containing dispersed PBT units, are embedded in a PBT matrix. The varied morphology affects the mechanical properties of the material, as the 60/40 blend displays a largely enhanced resistance to elongation, compared to the blends with lower PBT content.     

多单体接枝聚丙烯对PBT/PP共混体系的形态结构及力学性能影响研究

研究了甲基丙烯酸缩水甘油酯 (GMA)和苯乙烯 (St)多单体熔融接枝聚丙烯 (PP g (GMA co St) )对聚对苯二甲酸丁二酯 (PBT) 聚丙烯 (PP)共混物的形态结构和力学性能的影响 .利用双螺杆挤出机对PBT PP合金进行共混挤出 ,使用DSC、FT IR和SEM、TEM等手段对共混物进行了分析和相形态观察 ,并测试了力学性能 .实验证明 ,熔融共混过程中PP g (GMA co St)的环氧基团可以与PBT的端羧基发生化学反应 ,就地生成了PBT g PP共聚物 ,该共聚物可对PBT PP合金起到良好的增容剂作用 ,使共混物的相区尺寸显著减小 ,共混物的拉伸强度和冲击强度等力学性能同时得到明显改善 ,达到了弹性体系或小分子增容所难以达到的力学性能平衡的效果 .此外 ,TEM的研究还在PBT PP g (GMA co St)共混物中发现了特殊的微相分离结构     

Fully biodegradable blends of poly(butylene succinate) and poly(butylene carbonate): Miscibility, thermal properties, crystallization behavior and mechanical properties

Fully biodegradable poly(butylene succinate) (PBS) and poly(butylene carbonate) (PBC) blends were prepared by melt blending. Miscibility, thermal properties, crystallization behavior and mechanical properties of PBS/PBC blends were investigated by scanning electron microscopy (SEM), phase contrast optical microscopy (PCOM), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and mechanical properties tests. The SEM and PCOM results indicated that PBS was immiscible with PBC. The WAXD results showed that the crystal structures of both PBS and PBC were not changed by blending and the two components crystallized separately in the blends. The isothermal crystallization data showed that the crystallization rate of PBS increased with the increase of PBC content in the blends. The impact strength of PBS was improved significantly by blending with PBC. When the PBC content was 40%, the impact strength of PBS was increased by nearly 9 times.     

CaSO_4纳米晶须对PBT-PE-液晶离聚物杂化材料形态结构与力学性能的影响

通过熔融共混法将CaSO4纳米晶须和含磺酸离子的液晶离聚物(LCI)与聚对苯二甲酸丁二醇酯-聚乙烯(PBT-PE),制成PBT-PE-LCI-CaSO4纳米晶须杂化材料。通过DSC、红外图像系统分析和拉伸试验对共混体系的热性能、形态结构和力学性能进行了研究。结果表明:在共混体系中加入LCI提高了体系中PE的结晶温度和结晶度,并且LCI包裹着CaSO4纳米晶须,分散相PE均匀地分散在PBT基体中;当基体与CaSO4纳米晶须的质量比为100∶3时,杂化材料的力学性能最好。     

Preparation and characterization of poly(propylene carbonate)/montmorillonite nanocomposites by solution intercalation

Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate. However, the poor thermal stability and low glass transition temperatures (T_g) have limited its applications. To improve the thermal properties of PPC, organophilic montmorillonite (OMMT) was mixed with PPC by a solution intercalation method to produce nanocomposites. An intercalated-and-flocculated structure of PPC/OMMT nanocomposites was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal and mechanical properties of PPC/OMMT nanocomposites were investigated by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), and electronic tensile tester. Due to the nanometer-sized dispersion of layered silicate in polymer matrix, PPC/OMMT nanocomposites exhibit improved thermal and mechanical properties than pure PPC. When the OMMT content is 4 wt%, the PPC/OMMT nanocomposite shows the best thermal and mechanical properties. These results indicate that nanocomposition is an efficient and convenient method to improve the properties of PPC.     

Morphology and Mechanical Properties of Nylon 6/PBT Blends Compatibilized with Styrene/Maleic Anhydride Copolymer

The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly(butylenes terephthalate)(PBT),with styrene/maleic anhydride(SMA)as compatibilizer,were studied.The observation on the morphologies of the etched surfaces of the cryogenically fractured specimens via scanning electron microscopy(SEM)demonstrated that in the compatibilized Nylon 6/PBT blends,there exists a finer and more uniform dispersion induced by the in-situ interfacial chemical reactions during the preparation than that in the corresponding uncompatibilized blends.On the other hand,the overall mechanical properties of the compatibilized blends could be remarkably improved compared with those of the uncompatibilized ones.Moreover,increasing the amount of the compatibilizer SMA leads to a more efficient dispersion of the PBT phase in Nylon 6/PBT blends.Furthermore,there exists an optimum level of SMA added to achieve the maximum mechanical properties.As far as the mechanism of this reactive compatibilization is concerned,the enhanced interfacial adhesion is necessary to obtain improved dispersion,stable phase morphology,and better mechanical properties.     

三元乙丙橡胶环氧化增韧聚对苯二甲酸丁二酯的研究

三元乙丙橡胶环氧化增韧聚对苯二甲酸丁二酯的研究王学会，张会轩，王新华，王志刚，蒋俊光，姜炳政（吉林工学院化工系，长春，１３００１２）（中国科学院长春应用化学研究所）关键词三元乙丙橡胶，环氧化，ＰＢＴ，增韧作用，共混物聚对苯二甲酸丁二酯（ＰＢＴ）具有优...     

Novel copolyesters based on poly(alkylene dicarboxylate)s: 1. Thermal behavior and biodegradation of aliphatic-aromatic random copolymers

In order to improve the thermal and mechanical properties of the poly(butylene 1,12-dodecanedioate), some novel aliphatic-aromatic random copolyesters have been prepared by starting from 1,4-butanediol and different molar ratio of 1,12-dodecanedioc acid and terephthalic acid. The samples were characterized by ¹H NMR and the molecular structure was correlated with the crystalline phase present, the level of crystallinity, the glass transition temperature, the mechanical behavior, and the biodegradability. In particular, the copolymer containing the 70 mol% of PBT repeating units notably improves the thermal and mechanical properties of the poly(butylene 1,12-dodecanedioate) towards those of PBT and maintains a very high thermal stability, but loses the biodegradability of the poly(alkylene dicarboxylate). Therefore, for this class of aliphatic-aromatic copolymers the chemical composition must be carefully chosen to reach a compromise between good thermal and mechanical performances and biodegradability, according to the necessity.     

一类含萘环结构的聚酯酰亚胺液晶聚合物的结构与性能研究

利用Higashi芳香聚酯直接缩聚法的原理,采用分步投料的方法,以N,N′-1,6-亚己基-双苯偏三酸酰亚胺二酸(IA6)、6-羟基-乙-萘甲酸(HNA)和4,4′-二羟基二苯酮(DHBP)为单体原料,合成了一系列聚酯酰亚胺共聚物.用核磁共振(NMR)、差热分析(DSC)、偏光显微镜(PLM)、广角X射线衍射(WAXD)、热重分析(TGA)等手段对所合成的聚酯酰亚胺的液晶行为、结构以及热性能进行了表征.研究结果表明,当HNA投料量占单体总投料量高于33mol%时,所得聚合物均呈明显的向列型热致液晶特性.但是,此类液晶聚合物仅在升温过程中出现液晶的相转变,而在降温过程中并未观察到液晶的相转变行为.由DSC结果分析可知,此类聚合物具有较高的玻璃化转变温度(Tg)和较低的熔融温度(Tm),有望成为一类既具有较低加工温度又有较高使用温度的液晶聚合物材料.     

PBT/POE-g-MAH/PP共混体系的相态结构与性能

采用马来酸酐接枝乙烯-辛烯共聚物弹性体(POE-g-MAH)与聚丙烯(PP)在双螺杆挤出机上进行熔融共混,制备了3种新型增韧改性剂.研究了增韧改性剂的种类及其用量对共混物的力学性能、相形态结构、熔融与结晶行为的影响.力学性能测试表明,POE-g-MAH与适量PP并用具有显著的协同增韧作用,当POE-g-MAH与PP的配比为70/30时,所得增韧改性剂(POEg2)具有最佳的增韧效果.当POEg2含量达到15%时,共混物的缺口冲击强度(Is)从纯PBT的7.5 kJ/m2提高到51.2 kJ/m2,与15%的纯POE-g-MAH弹性体增韧PBT具有相近的缺口冲击强度值.同时,共混物的拉伸强度(σb)损失最小.采用AFM和SEM观察发现,新型增韧改性剂作为分散相具有软壳-硬核结构.DSC测试表明,随增韧改性剂中PP含量增加到一定值时,壳-核结构中软壳层出现不完整现象,导致界面作用力减小,共混物的Is和σb都出现明显下降.     

膨胀型环状类磷酸酯蜜胺盐阻燃剂的合成及阻燃聚丙烯的结构与性能

以双季戊四醇、三季戊四醇、多聚磷酸、五氧化二磷和三聚氰胺为原料,合成了膨胀型环状类磷酸酯蜜胺盐阻燃剂,并与聚丙烯共混制成阻燃聚丙烯.红外分析表明该阻燃剂具有环状结构.通过扫描电镜和X射线衍射对阻燃聚丙烯进行了结构分析和表面纹理的表征.实验结果表明：该阻燃剂阻燃性能良好,但在聚丙烯中的分散性较差;用甲基纤维素对该阻燃剂进行表面化学修饰以后,该阻燃剂在聚丙烯中的分散性及阻燃材料的机械性能得到了明显的改善.     

The effect of nucleating agents on the crystallization kinetics of polypropylene

Compositions of neat polyproylene (PP), PP–PE (polyethylene) blend and PP–PE–DBS (dibenzylidene sorbitol) were studied with respect to their crystallization kinetics by means of differential scanning calorimetry in isothermal mode. A modified Avrami equation was applied to obtain the crystallization parameters of PP, PP–PE and PP–PE–DBS. Optical and hot-stage microscopy and dynamical analysis were used for structure determination. Experimental results have indicated that PE addition inhibits PP crystallization rate and acts as a plasticizer, while addition of DBS changes the crystallization kinetics. A detailed study of the DBS nucleation effects indicates that owing to the high surface energy, nuclei are formed during primary crystallization, leading to a fine PP crystalline structure and improved mechanical properties.     

Simultaneously Improving the Tensile and Impact Properties of Isotactic Polypropylene with the Cooperation of co-PP and β-nucleating Agent through Pressure Vibration Injection Molding

In this article, crystalline morphology and molecular orientation of isotactic polypropylene(i PP), random copolymerized polypropylene(co-PP) and ?-nucleating agent(?-NA) composites prepared by pressure vibration injection molding(PVIM) have been investigated via polarized light microscopy, scanning electron microscopy, wide-angle X-ray diffraction and differential scanning calorimetry. Results demonstrated that the interaction between co-PP and i PP molecular chains was beneficial for the mechanical improvement and the introduction of ?-NA further improved the toughness of i PP. In addition, after applying the pressure vibration injection molding(PVIM) technology, the shear layer thickness increased remarkably and the tensile strength improved consequently. Thus, the strength and toughness of i PP/co-PP/?-NA composites prepared by PVIM were simultaneously improved compared to those of the pure i PP prepared by conventional injection molding(CIM): the impact toughness was increased by five times and tensile strength was increased by 9 MPa. This work provided a new method to further enhance the properties of i PP/co-PP composites through dynamic processing strategy.     

碳纳米管对聚酯相容共混体系酯交换反应的影响

采用熔融共混制备了聚对苯二甲酸丙二酯(PTT)/聚对苯二甲酸丁二酯(PBT)共混体系以及碳纳米管(C NTs)填充改性的三元复合体系,通过核磁共振波谱仪(NMR)研究了CNTs对共混基体组分间酯交换反应的影响,并结合透射电子显微镜( TEM)、沉降实验等多种测试结果初步探讨了影响的机理.研究结果表明,PTT/PBT为典...     

碳纳米管改性聚苯硫醚熔纺纤维的结构与性能研究

将多壁碳纳米管(MWCNTs)和聚苯硫醚(PPS)经过熔融挤出后制备成复合材料切片,并采用熔融纺丝法制得碳纳米管改性聚苯硫醚复合纤维.采用扫描电镜(SEM)、拉曼光谱、示差扫描量热分析(DSC)、动态机械分析(DMA)以及力学性能测试等表征手段研究了复合纤维中碳管的分散状态,与基体的界面作用,复合纤维的结晶性能以及力学性能,从而探讨了聚苯硫醚/碳纳米管复合纤维体系的微观结构与宏观性能之间的关系.研究表明,聚苯硫醚分子结构与碳纳米管之间具有的π-π共轭作用使碳管较为均匀的分散在基体中,界面结合较为紧密.同时熔融纺丝过程中的拉伸作用使碳管进一步解缠并使碳管沿纤维拉伸方向取向.另一方面,拉曼光谱显示拉伸作用有效地增强了界面作用,有利于外界应力的传递.碳管的良好分散以及强的界面作用使复合纤维力学性能得到大幅度的提高,当碳管含量达到5 wt%时,复合纤维的模量有了明显的提高,拉伸强度较纯PPS纤维提高了近220%.