E/VAC对PC/PBT共混体系性能的影响

针对聚碳酸酯(PC)／聚对苯二甲酸丁二酯(PBT)共混体系相容性差的缺点,采用(乙烯／乙酸乙烯酯)共聚物(E／VAC)作增容剂对其进行改性。研究了E／VAC对PC／PBT共混体系结晶性能和力学性能的影响,并用扫描电子显微镜观察了共混体系的形态结构。结果表明,E／VAC可以提高PC／PBT共混体系的相容性,当E／VAC含量为2％时共混体系的综合性能较好。试验还发现加入E／VAC后PC／PBT共混体系有良好的成型加工性能。     

聚碳酸酯/聚苯乙烯合金微观结构的研究

制备了聚碳酸酯／聚苯乙烯(PC／PS)共混合金，并用扫描电镜(SEM)观察了PC／PS共混物的微观结构及其在不同混合加工过程中的形态变化。结果表明，共混物的形态结构强烈地依赖于共混物的组成和混合方法，相转变点的理论预测与实验值有一定的偏差。     

游离链段在PA6/ABS共混物中的作用研究

采用种子乳液聚合方法合成了丙烯腈-丁二烯-苯乙烯共聚物(ABS)改性剂,采用超速离心分离方法,分离出ABS改性剂中的游离SAN链段。采用熔融共混技术,将ABS改性剂与聚己内酰胺(PA6)进行共混,研究了ABS改性剂中游离的SAN链段对PA6/ABS共混物性能的影响。结果表明,去除ABS改性剂中的游离SAN链段后,对PA6/ABS共混体系的加工流动性影响不大。除去ABS改性剂中的游离链,对共混物的弹性模量和屈服强度影响不大,共混物的冲击强度和断裂伸长率明显提高。动态力学分析仪(DMA)测试发现PA6/ABS共混体系的相容性有所改善,扫描电子显微镜(SEM)形态表明,分离游离链后核壳粒子更加均匀地分散在共混物中。     

HDPE/PC/EVA共混体系的性能研究

研究了乙烯-醋酸乙烯共聚物(EVA)增容高密度聚乙烯(HDPE)和聚碳酸酯(PC)共混体系，讨论了EVA，PC对HDPE／PC共混合金性能的影响。结果表明：随PC用量的增加，HDPE／PC共混合金的熔体流动速率减小，缺口冲击强度增大，拉伸强度增大，维卡软化点变化不大。EVA能够改善合金体系的加工流动性，却明显降低了合金体系的力学性能。     

相对分子质量对玻纤增强PBT/PC的影响

选用不同相对分子质量的聚对苯二甲酸丁二醇酯(PBT)及聚碳酸酯(PC)，通过双螺杆挤出机制备了一系列玻璃纤维增强PBT／PC的共混物。通过对共混物力学性能的测试以及用电子显微镜观察共混物的形态结构，研究了共混物组分的相对分子质量对共混体系的影响。结果表明，共混物组分的相对分子质量对共混物的相容性及性能影响非常显著。     

马来酸酐接枝PP／POE共混物对PC的改性研究

使用本实验室自制的(PP／POE)-g-MAH共混物作为聚碳酸酯(PC)的改性剂。研究了不同改性剂用量对PC共混物的力学、热学、加工及耐沸水性能的影响。结果表明，加入5％的(PP／POE)-g-MAH可明显提高PC的缺口冲击强度，改善PC的加工性能和耐沸水性能，从而得到一种综合性能较好的材料。同时使用扫描电镜对改性共混物的液氮脆断断面进行了观察。     

可互容的PVME/SAN共混物的微细结构

采用原子力显微镜的敲击模式来研究聚甲基乙烯基醚／苯乙烯-丙烯腈共聚物(PVME／SAN)共混物膜的表面，发现在相容的共混物中，存在着精细结构，其颗粒的大小分布与共聚物SAN中的丙烯腈体积分数呈规律性的变化。但在同样条件下得到的PVME／SAN 95(丙烯腈体积分数为95％)共混物试样用差示扫描量热法进行检测发现，共混物中只有1个热转变区。     

酯交换反应稳定剂对PBT／PC共混物性能和结构的影响

研究了亚磷酸三苯酯(TPPi)和焦磷酸二氢二钠(DSDP)对聚对苯二甲酸丁二醇酯(PBT)／聚碳酸酯(PC)共混体系中酯交换反应的抑制作用和对共混物性能和结构的影响。结果表明：TPPi和DSDP均能提高共混物的维卡温度，但是，在有增韧剂的PBT/PC共混体系中，TPPi会降低其冲击性能，DSDP则不会降低其冲击性能。对抽提分离物做的FTIR和DSC分析结果证实了DSDP是酯交换反应有效的稳定剂。     

PC/ABS共混改性的研究

运用二次通用旋转回归设计的方法，建立了共混合金组成与性能之间相互关联的数学模型，研究了PC／ABS共混体系在0水平时各组分及组分间交互作用对共混材料各项性能的影响。结果表明，共混体系中，PC含量是决定共混物力学性能的主要因素，PC、ABS的种类及其交互作用对体系的耐热性和强度等性能影响显著。     

HDPE/PC分散相纤维化及其原位复合材料的研究

将高密度聚乙烯(HDPE)和聚碳酸酯(PC)在双螺杆挤出机中熔融共混挤出，通过改变对挤出物施加的牵引速度，研究了拉伸力场对HDPE／PC共混物的形态及其原位复合材料性能的影响。结果表明，随着牵引速度的提高，纤维状分散相所占比例增加，但纤维直径无明显变化；HDPE／PC原位复合材料与其普通共混材料相比，拉伸强度基本无变化，但冲击强度提高较大。     

Effect of styrene–acrylonitrile on the electrical resistivity of polycarbonate/multiwalled carbon nanotube composites

Multiwalled carbon nanotube (MWCNT)‐filled polycarbonate (PC)/styrene–acrylonitrile (SAN) blends with a wide range of blend compositions were prepared by melt mixing in a rotational rheometer, and the effect of SAN on the electrical properties of the PC/MWCNT composites was studied. The structure/electrical property relationship was investigated and explained by a combination of MWCNT localization and blend morphology. Transmission electron micrographs showed selective localization of MWCNTs in the PC phase, regardless of the blend morphology. When the SAN concentration was 10–40 wt %, which corresponded to sea‐island (10–30 wt %) and cocontinuous (40 wt %) blend morphologies (PC was continuous in both structures), the electrical resistivity decreased with increases in the SAN content. The concept of an effective volume concentration of MWCNTs was used to explain this effect. When the SAN concentration was 70 wt % or higher, the electrical resistivity was very high because MWCNTs were confined in the isolated PC particles. In addition, SAN was replaced by other polymers [polystyrene, methyl methacrylate/styrene, and poly(methyl methacrylate)]; these yielded similar blend morphologies and MWCNT localization and showed the generality of the concept of effective concentration in explaining a decrease in the electrical resistivity upon the addition of a second polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Influence of a core/shell rubber phase on the morphology and the impact resistance of a PC/SAN blend (75/25)

At 75/25 concentration ratio, bisphenol a polycarbonate (PC)/styreneacry-lonitrile copolymer (SAN) blend has poor impact resistance compared to PC/ABS. A rubber phase methacrylate-butadiene-styrene (MBS) of core/shell type was dispersed in PC/SAN blend. The morphology of the unmodified and modified blend was investigated. The influence of the acrylonitrile ratio in the SAN on the microstructure was studied. It clearly shows that core/shell resides at the interface between PC and SAN. It seems that core/shell particles enhance the adhesion between the different phases. Their presence influences the interface mobility; i.e., the coalescence of the dispersed phase observed in pure PC/SAN is considerably reduced when the MBS particles are added. The impact resistance of the samples was correlated with the morphology.     

Effects of AN-contents and shear flow on the miscibility of PC/SAN blends

The miscibility of polycarbonate (PC) with styrene-co-acrylonitrile random copolymer (SAN) has been systematically investigated as functions of acrylonitrile content and shear flow. Various AN-contents ranged from 11 to 74 wt% and different simple shear flow values up to 90 s⁻¹ have been used to explore the effect of both material and proceeding parameters on the miscibility of PC and SAN blends. The finest phase dispersion of the SAN particles was observed at AN=25 wt% for PC/SAN=70/30 blends under the same processing condition using scanning electron microscope (SEM). The obtained morphologies indicated that PC and SAN could form a partial miscibility blend and the maximum miscibility occurred at AN=25 wt%. This observation was supported by considering the shifts in the glass processes of the two rich phases of the blend using the dynamical mechanical analysis (DMA) measurements. The optimum interaction of the two components at AN=25 wt% calculated from ellipsometric technique was found to be the only responsible parameter for the high miscibility of the blend. The viscoelastic properties of the pure polymer components were found to play a minor role in the obtained morphologies. The effect of simple shear flow on the morphology of PC/SAN-25=70/30 blend has been also investigated using a special shear apparatus of parallel plate geometry. It has been found that the dispersed phase of SAN was elongated and broken-up in the direction of flow with weaker contrast at high shear rates. The shear rate was found to enhance the miscibility of SAN (dispersed phase) in the PC matrix to a great extent as seen in the weak contrast of the two phases observed by transmission electron microscope (TEM).     

Influence of blend composition on the mechanical properties and morphology of PC/ASA/SAN ternary blends

Bisphenol A polycarbonate/acrylonitrile–styrene–acrylic/styrene–acrylonitrile copolymer (PC/ASA/SAN) ternary blends were prepared over a range of compositions via mixing PC, SAN, and ASA copolymer by melt blending. An analysis was made on the mechanical properties and morphology of the blends. Special care was taken to make comparisons of the morphologies and properties of blends with different SAN content. When a small amount SAN was introduced to PC/ASA blends, the dispersion condition of ASA in the matrix was improved and a better integrated mechanical properties was realized. Further increasing the SAN content led to a decrease of impact strength, which was due to the changing of the morphology of the blends and the inherent brittleness of matrix. The study about the effect of ASA content on the properties of PC/ASA/SAN blends showed that the blend with 20 wt% ASA had good mechanical properties.     

Gloss reduction and morphological properties of polycarbonate and poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) blends with SAN‐co‐GMA as a reactive compatibilizer

The gloss properties of the polycarbonate (PC)/poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) (MABS) blend with styrene‐acrylonitrile‐co‐glycidyl methacrylate (SAN‐co‐GMA) as a compatibilizing agent were investigated. For the PC/poly(MABS)/SAN‐co‐GMA (65/15/20, wt %) blend surface, the reduction of gloss level was observed most significantly when the GMA content was 0.1 wt %, compared with the blends with 0.05 wt % GMA or without GMA content. The gloss level of the PC/poly(MABS)/SAN‐co‐GMA (0.1 wt % GMA) blend surface was observed to be 35, which showed 65% lower than the PC/poly(MABS)/SAN‐co‐GMA blend without GMA content. The gloss reduction was most probably caused by the insoluble fractions of the PC/poly(MABS)/SAN‐co‐GMA blend that were formed by the reaction between the carboxylic acid group in poly(MABS) and epoxy group in SAN‐co‐GMA. The results of optical and transmission electron microscope analysis, spectroscopy study, and rheological properties supported the formation of insoluble structure of the PC/poly(MABS)/SAN‐co‐GMA blend when the GMA content was 0.1 wt %. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46450.     

Polycarbonate/acrylonitrile–styrene–acrylic elastomer terpolymer blends with enhanced interfacial adhesion and surface gloss

A blend of bisphenol A polycarbonate (PC) and an acrylonitrile–styrene–acrylic elastomer (ASA) terpolymer with high surface gloss and excellent interfacial properties was developed for automobile applications. Because PC and the styrene‐co‐acrylonitrile (SAN) copolymer that formed the matrix in the PC/ASA blend were not miscible, two different types of compatibilizers were examined to improve the compatibility of the blend. A diblock copolymer composed of tetramethyl polycarbonate and poly(methyl methacrylate) (PMMA) was more effective than PMMA in increasing interfacial adhesion between PC and SAN. The surface gloss of the PC/ASA blend was always lower than that of the pure ASA included in the blend because of PC existing at the surface of the injection‐molding specimen. The PC/ASA blend with optimum surface gloss and enhanced interfacial adhesion was developed through the control of the molecular weight of PC and the compatibilizer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2097–2104, 2005     

SAN/高胶粉/有机硅共混物的制备与性能研究

利用熔融共混法制备了苯乙烯-丙烯腈共聚物(SAN)/高胶粉/有机硅共混物,研究了高胶粉和有机硅用量对共混物力学性能和流动性能的影响。结果表明:随着高胶粉用量的增加,共混物的冲击强度提高,流动性能下降,当高胶粉/SAN=30/70时,共混物综合性能最佳;当有机硅用量为0.2%时,共混物的刚性和流动性能变化不大,但冲击强度得到大幅度提高。     

Dynamic‐mechanical analysis of MWNTs‐filled PC/ABS blends

In a systematic manner, the roles of MWNTs as filler and styrene acrylonitrile copolymer‐graft‐maleic anhydride (SAN‐MA) as compatibilizer, individually and together, on dynamic‐mechanical behavior of polycarbonate (PC)‐rich/acrylonitrile butadiene styrene terpolymer (ABS) blend were studied. The investigations were performed using small‐scale mixing in a one‐step procedure with a fixed MWNTs content of 0.75 wt% and a blend composition of PC/ABS = 70/30 w/w. PC/SAN blends and nanocomposites as simpler model system for PC/ABS were also studied to reveal the role of the rubbery polybutadiene (PB) fraction. It is found that the tendency of MWNTs to localize within the PC component in compatibilized PC/ABS was lower than in compatibilized PC/SAN blends. Dynamic mechanical analysis (DMA) revealed the dual role of SAN‐MA as blend compatibilizer and also promoter of MWNTs migration towards PC, where SAN‐MA to MWNTs weight ratio varied between 1 and 4. At the compatibilizer/MWNTs weight ratio of 1, MWNTs localized in PC component of the blends whereas increasing the compatibilizer/MWNTs ratio to 4 led to migration of MWNTs toward SAN or ABS component. In DMA studies, loss modulus normalization of the nanocomposites revealed the coexistence of mobilized and immobilized regions within the nanocomposite structure, as a result of MWNTs and compatibilizer loading. POLYM. ENG. SCI., 54:2696–2706, 2014. © 2014 Society of Plastics Engineers     

Influence of the viscosity ratio in PC/SAN blends filled with MWCNTs on the morphological,electrical, and melt rheological properties

Co-continuous polycarbonate (PC)/poly(styrene-acrylonitrile) (SAN) = 60/40 wt.% blends were filled with 1 wt.% multi-walled carbon nanotubes (MWCNTs), which selectively localized within the PC component. To study the influence of the viscosity ratio, PCs with different viscosities were selected resulting in PC/SAN viscosity ratios (at 100 rad/s) between 1.2 and 4.5. With increasing viscosity ratio, smaller blend structures were observed. Furthermore, optical microscopy revealed that the filler dispersion was improved with decreasing PC viscosity. The highest electrical conductivity was achieved for the blend composite with the coarsest morphology, containing the low viscosity PC and having the lowest PC/SAN viscosity ratio. Transmission electron microscopy analysis indicated that for the composite prepared with high viscosity PC, not all of the incorporated MWCNTs were able to localize completely into the PC component. Instead, some MWCNTs were found to be stacked at the interface of the two polymers, indicating that the high PC melt viscosity had a restricting effect on the movement of the MWCNTs. Moreover, with electrical conductive atomic force microscopy, it was proven that small, spherical PC particles, even if filled with CNTs, do not take part in the conductive network of the blend composites. Rheological analyses showed a correlation with the morphological analysis and the electrical conductive behavior of the blend composites. In summary, a lower viscosity ratio between the blend components, in which upon addition due to thermodynamic reasons the CNTs localize (here PC), and the other component (here SAN) is favorable for high electrical conductivity values.     

Visco-elastic properties related to the phase morphology of 60/40 PC/SAN blend

Stress relaxation and dynamic mechanical measurements have been performed on a 60/40 blend of polycarbonate of bisphenol A (PC) and poly (styrene-co-acrylonitrile) (SAN). This paper clearly demonstrates that the phase morphology of an immiscible co-continuous polymer blend is an important parameter in determining visco-elastic behavior. The dynamic mechanical properties are discussed in terms of the visco-elastic form of a Kerner equation as a function of the reciprocal Chalkey parameter, which has been used to quantify the co-continuous phase morphology. The effective volume fraction of the SAN phase has been found to decrease as the phase structure coarsens during annealing above T_g of both SAN and PC. This is probably the result of phase break-up and subsequent inclusion of SAN domains in the PC matrix during the coarsening process, which modifies the structure produced during melt compounding and injection molding.