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。     

PTW对PA1010/PP共混物的增容作用

为了增加聚酰胺1010/聚丙烯(PA1010/PP)共混物的相容性,提高共混物的力学性能,采用一种新型的反应型增容剂乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PTW)进行增容,通过扫描电镜(SEM)、力学性能、傅里叶变换红外光谱(FTIR)和差示扫描量热(DSC)测试,研究了PTW对PA1010/PP共混物的增容作用.结果表明,随着PTW的加入,共混物的相区尺寸明显变小,当PA1010/PP/PTW质量比为70∶30∶7时,分散相尺寸细小而均匀,表明PTW有较好的增容作用.FTIR结果表明,PTW上的环氧基团和PA1010在熔融共混中发生了化学反应.DSC研究结果表明,PA1010的结晶温度随PTW的加入而降低,说明PTW对PA1010结晶有抑制作用.另外,PTW的加入使PP的结晶温度下降,当PTW质量分数为5%时出现2个结晶峰,即出现异相成核结晶和均相成核结晶,PP均相成核结晶的出现从另一个方面说明,在PA1010基体中分散相PP尺寸非常细小.当PTW质量分数为7%时共混物的力学性能最佳,干态冲击强度达到13.93kJ/m2,是未加增容剂时的2倍,拉伸和弯曲性能基本不变.PTW的增容机理在于其分子链中的甲基丙烯酸缩水甘油酯能与PA1010发生化学反应,而乙烯链段与PP有较好的亲和性,从而降低界面张力,减少相区尺寸,大幅度提高力学性能.     

聚苯醚羧酸酯对C-PPO/PS共混体系的增容作用

前曾报道羧化度为8～lOmol%的羧化聚苯醚(C-PPO)与PS共混体系具有UCST和LCST共存的特殊相行为^[1],而羧化度大于11.6mol%时,C-PPO/PS共混体系表现出不相容性^[2,3]。化学改性PPO可作为PPO与其他聚合物共混的增容剂。本文讨论C-PPO的正十二酯(Lau-CPPO)对C-PPO/PO共混体系混溶性的影响。     

辐射增强PP／BR共混体系的力学性能

研究了在多官能团单体－三烯丙基异氰酸酯存在下，共混体系聚丙烯／１．４－聚丁二烯橡胶的辐射效应，用ＤＳＣ，动态粘弹谱对其进行表征。结果显示，三烯丙基异氰酸酯主要分布于聚丙烯／１．４－聚丁二烯橡胶共混物的界面自高能射线作用下，被引发参与界面反应，从而改善了共混体系的相容性，增强也界面粘接，提高了共混物的力学性能。     

增容聚苯乙烯共混物的研究进展

综述了增容聚苯乙烯与聚乙烯、聚丙烯、聚酰胺共混物的研究进展。不同共混物采用不同的增容剂,可使增容聚苯乙烯共混物改善分散相尺寸、界面相互作用与粘结,达到提高共混物的力学性能的目的。增容效果与增容剂的类型、用量和分子结构有关。     

反应性单体改性PP/PS共混物结晶与熔融行为

制备了三种反应性单体和两种PP接枝物改性的PP／PS共混物,用DSC研究了改性PP／PS共混物的结晶与熔融行为。结果表明：PS的加入提高了PP的结晶温度,两种接枝物的加入进一步提高共混物中PP的结晶温度,少量反应性单体对结晶温度影响不大,但高用量时则明显提高共混物的结晶温度;外加接枝物或者反应性单体对共混物中PP的熔融温度影响不大,但是熔融峰形与结晶温度高低有关。     

PP/EPDM共混物热氧稳定性研究

通过热氧加速老化的方法研究了不同的EPDM含量和抗氧剂对聚丙烯和三元乙丙橡胶共混物(PP/EPDM)热氧稳定性的影响.通过对老化前后试样的力学性能变化分析,热失重(TG)分析和扫描电镜(SEM)分析,结果表明:在热氧加速老化的初期,PP/EPDM共混物的拉伸强度随着时间的增长呈逐渐上升的趋势;在老化中期,共混物的拉伸强度变化不大;在老化后期,共混物的拉伸强度逐渐下降.在整个老化过程中,断裂伸长率都呈逐渐下降的趋势.而随着EPDM含量的增加,相应共混物的拉伸强度和断裂伸长率的下降减缓;相应共混物的分解温度得到较大的提高;抗氧剂的加入,能进一步提高共混物的热氧稳定性.     

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     

聚丙烯／氯化聚乙烯共混物的形态结构

 用透射电子显微镜方法研究了聚丙烯（ｉＰＰ）和氯化聚乙烯（ＣＰＥ）共混物溶液浇铸膜的形态结构．共混物中ＣＰＥ含量≤７０％时不妨碍ｉＰＰ球晶两种结构（交叉结构和条状结构）区域的生成．在ＣＰＥ含量≥８０％时，分散相ｉＰＰ形成近乎直角（８０°）交叉的稀疏的片晶网络．在共混物的全组成范围内，ＣＰＥ结晶在ｉＰＰ片晶上附生生长，二者结晶Ｃ轴的交角为５０°     

RPS／CPE的反应性共混及其对PS／PE的增容作用

用ＦＴＩＲ、ＤＳＣ等方法研究了含恶唑啉官能力的聚苯乙烯（ＲＰＳ）与氯化聚乙烯（ＣＰＥ）之间的反应。ＲＰＳ、ＣＰＥ、ＰＳ、ＰＥ在不同温度下用反应式挤出要熔融共辊，结果表明，ＲＰＳ／ＣＰＥ对ＰＳ／ＰＥ共混物具有增容作用，提高了共混物的力学性能。此反应性共混适宜在较低温度下进行，对ＲＰＳＣＰＥ共混物还进行了动态力学表征，并与ＲＰＳ进行比较以进一步了解共混物的特征。     

Compatibilization efficiency of styrene–butadiene multiblock copolymers in PS/PP blends

The compatibilizing effect of di‐, tri‐, penta‐, and heptablock (two types) copolymers with styrene and butadiene blocks was studied in polystyrene/polypropylene (PS/PP) 4/1 blends. The structure of PS/PP blends with the addition of 5 or 10 wt % of a block copolymer (BC) was determined on several scale levels by means of transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS). The results of the structure analysis were correlated with measured stress‐transfer properties: elongation at break, impact, and tensile strength. Despite the fact that the molar mass of the PS blocks in all the BCs used was about 10,000, that is, below the critical value M^* (～18,000) necessary for the formation of entanglements of PS chains, all the BCs used were found to be good compatibilizers. According to TEM, a certain amount of a BC is localized at the interface in all the analyzed samples, and this results in a finer dispersion of the PP particles in the PS matrix, the effect being more pronounced with S‐B‐S triblock and S‐B‐S‐B‐S pentablock copolymers. The addition of these two BCs to the PS/PP blend also has the most pronounced effect on the improvement of mechanical properties of these blends. Hence, these two BCs can be assumed to be better compatibilizers for the PS/PP (4/1) blend than the S‐B diblock as well as both S‐B‐S‐B‐S‐B‐S and B‐S‐B‐S‐B‐S‐B heptablock copolymers. In both types of PS/PP/BC blends (5 or 10 wt % BC), the BC added was distributed between both the PS/PP interface and the PS phase, and, according to SAXS, it maintained a more or less ordered supermolecular structure of neat BCs. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 931–942, 2001     

The influence of nano‐PS particle on structure evolution and electrical properties of PP/PS

The polypropylene‐g‐polystyrene (PP‐g‐PS) copolymers with different grafting ratios are used as compatibilizers to control the size of polystyrene (PS) particles at nanometer scale in polypropylene (PP) matrix. Then the PP/PS insulating nanocomposites (containing 10 wt % PS calculated from PS and PP‐g‐PS) are manufactured. With the increase in grafting ratio of PP‐g‐PS, the size of PS particle is reduced and the interfacial adhesion is enhanced. Meanwhile, the dielectric properties, DC breakdown strength and volume resistivity are increased with the decreasing of PS particle size. The spherulite size of PP is decreased and the boundary between crystals and amorphous regions is blurred or even disappears due to the presence of PS nanoparticles. This evolution of PP structure is attributed to the serious entanglements of PP and PS molecular chains. Finally, the correlation between morphological structure and electrical properties is ultimately established based on the in‐depth understanding of the molecular chain movement, crystal structure, and phase morphology. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 706–717     

Phase morphology and mechanical properties of iPP/SEP blends

The effects of the addition of diblock copolymer poly(styrene‐b‐ethylene‐co‐propylene) (SEP) to isotactic polypropylene (iPP) on the morphology and mechanical properties were investigated. Phase morphologies of iPP/SEP blends up to a 70/30 weight ratio, prepared in Brabender Plasticoder, were studied with optical microscopy, scanning electron microscopy, transmission electron microscopy, and wide‐angle X‐ray diffraction. The addition of 2.5 wt % SEP caused a nucleation effect (by decreasing the crystallite and spherulite size) and randomization of the crystallites. With further SEP addition, the crystallite and spherulite size increased because of prolonged solidification and crystallization and achieved the maximum in the 80/20 iPP/SEP blend. This maximum was a result of the appearance of β spherulites and the presence of mixed α spherulites in the 80/20 iPP/SEP blend. Dispersed SEP particles were irregular and elongated clusters consisting of oval and spherical core–shell microdomains or SEP micelles. SEP clusters accommodated their shapes to interlamellar and interspherulitic regions, which enabled a well‐developed spherulitization even in the 70/30 iPP/SEP blend. The addition of SEP decreased the yield stress, elongation at yield, and Young's modulus but significantly improved the notched impact strength with respect to the strength of pure iPP at room temperature. Some theoretical models for the determination of Young's modulus of iPP/SEP blends were applied for a comparison with the experimental results. The experimental line was closest to the Takayanagi series model. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 566–580, 2001     

Influence of Reactive Compatibilization on the Morphology of Polypropylene/Polystyrene Blends

To study the efficiency of different mechanisms for reactive compatibilization of polypropylene/polystyrene blends (PP/PS blends), main chain or terminal-functionalized PP and terminal-functionalized PS have been synthesized by different methods. While the in-situ block and graft copolymer formation results in finer phase morphologies compared to the corresponding non-reactive blends, the morphology development in the ternary blend system PP/PS + HBP (hyperbranched polymer) is a very complex process. HBP with carboxylic acid end groups reacts preferably with the reactive sites of the oxazoline functionalized PS (PS-Ox) and locates mainly within the dispersed PS-Ox phase. A bimodal size distribution of the PS-Ox particles within the oxazoline modified PP (PP-Ox) matrix phase is observed with big PS-Ox particles (containing the HBP as dispersed phase) and small PS-Ox particles similar in size to the unimodal distributed particles in the non-reactive PP-Ox/PS-Ox blends. Factors influencing the morphology are discussed.     

RPS增容LDPE／PS研究

用ＨＡＡＫＥ、ＤＳＣ、ＩＲ等方法研究了侧基含有过氧键的反聚苯乙烯与ＬＤＰＥ之间的反应，并将其应用到ＬＤＰＥ／ＰＳ共混体系。考察了不同添加方式，交联助剂等对共混物力学性能、流变性能及微观结构的影响。     

Effect of dispersed phase composition on morphological and mechanical properties of PET/EVA/PP ternary blends

Immiscible ternary blends of PET/EVA/PP (PET as the matrix and (PP/EVA) composition ratio = 1/1) were prepared by melt mixing. Scanning electron microscope results showed core‐shell type morphology for this ternary blend. Binary blends of PET/PP and PET/EVA were also prepared as control samples. Two grades of EVA with various viscosities, one higher and the other one lower than that of PP, were used to investigate the effect of components' viscosity on the droplet size of disperse phase. The effect of interfacial tension, elasticity, and viscosity on the disperse phase size of both binary and ternary blends was investigated. Variation of tensile modulus of both binary and ternary blends with dispersed phase content was also studied. Experimental results obtained for modulus of PET/EVA binary blends, showed no significant deviations from Takayanagi model, where considerable deviations were observed for PET/PP binary blends. Here, this model that has been originally proposed for binary blends was improved to become applicable for the prediction of the tensile modulus of ternary blends. The new modified model showed good agreement with the experimental data obtained in this study. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 251–259, 2010     

Study on In-Situ Compatibilization of the PP/PA6 Blends in Twin Screw Extruders

The in-situ compatibilization of PP/PA6 blend was studied in a twin screw extruder. The maleic anhydride (MA) content, peroxide concentration, shear rate and feeding order were among the variables investigated. Degree of grafting of samples collected prior to feeding of PA6 into the extruder was measured using titration combined with FTIR technique. From the SEM results it was found that the increasing of initial MA concentration led to larger PA particle size which could be related to secondary reactions between excess MA and PA. The melt linear viscoelastic measurements performed on the blend samples and the obtained relaxation time spectra showed shorter form relaxation time and interfacial relaxation time for one-step compatibilized sample compared to the sample prepared by the two-step method with the same degree of grafting. This was attributed to the stronger interfacial interaction of the one-step compatibilized blend samples which could be resulted from greater efficiency of grafting and/or compatibilization. These results were supported by SEM results which showed smaller particle size for the one-step compatibilized samples. It was demonstrated that melt linear viscoelastic measurement could provide a great insight into understanding the compatibilization process in twin screw extruder.     

HIPS／PP熔融反应共混及其动态力学性质

研究了高抗冲聚苯乙烯（HIPS）／聚丙烯（PP）共混物在过氧化二异丙苯（DCP）存在下的熔融反应过程及其动态力学性质．HIPS在DCP存在下以聚苯乙烯（PS）的降解为主，伴随着聚丁二烯（PB）的交联和接枝，PP在DCP存在下以降解为主，HIPS／PP在DCP存在下以PP同HIPS的反应接枝为主，这种原位生成的增容剂显著地改善了HIPS／PP两组份间的相容性，其分子运动特征较前两者发生明显变化，PS的Tg下降，PB和PP的Tg升高．