马来酸酐接枝氢化苯乙烯—丁二烯嵌段共取物增韧聚苯醚体系的韧性、亚微相态的流变性能

考察了氢化苯乙烯－丁二烯嵌段共聚弹性体（SEBS）及其马来酸酐接枝共聚物（SEBS－g/MA)增韧聚苯醚（PPO）体系，DSC谱图显示，PPO与SEBS的共混物仅有一个Tg，两者完全相容；PPO与SEBS－g-MA的共混物存在两个Tg，只能达到部分相容。力学性能研究表明，在PPO／SEBS体系中，基体只发散相SEBS的相界面模糊，无法引发基体银纹和剪切屈服，增韧PPO的效果有限；而部分相容的PPO／SEBS－g-MA共混物显示了增韧剂良好的相界面引发基体银纹和剪切屈服的作用，其缺口冲击强度在SEBS-g-MA质量分数为20％时达到1260J／m的超韧性。亚微相态显示，SEBS和PPO中呈现条形分散相的“海岛”结构；而EBS－g-MA在基体中呈现网络结构。流变性能研究显示，PPO／SEBS共混物的表观粘度均高于PPO，并随SEBS的含量增加而变大；而PO／SEBS－g-MA则完全相反。     

马来酸酐化SEBS对尼龙1212/尼龙6共混体系形态和性能的影响

研究了马来酸酐接枝氢化苯乙烯 丁二烯 苯乙烯嵌段共聚物 (MA SEBS)对尼龙 12 12 尼龙 6共混体系形态和性能影响 .结果表明 ,在以尼龙 6为连续相而尼龙 12 12为分散相时 ,MA SEBS加入大大提高了两相间的相容性 ,导致尼龙 12 12分散相的细化 .透射电镜观察表明 ,共混体系形成特殊的“核 壳”结构 ,处在分散相和连续相间的“壳”MA SEBS起到了很好的相容剂的作用 .在尼龙 12 12 尼龙 6为 30 70时 ,仅用 15 %的MA SEBS ,共混体系即获得超高韧性 .     

基于UPLC-QTOF MS的食品接触用回收PET中非挥发性有机物的非靶向筛查

采用超高效液相色谱－串联四极杆飞行时间质谱技术（UPLC－QTOF MS）对经初步清洗后的回收聚对苯二甲酸乙二醇酯（rPET）瓶片中潜在的非挥发性有机物进行非靶向筛查,并考察了不同沉淀溶剂、去除溶剂方式、测试样品量等前处理方法,以及不同测试方法、流动相及洗脱剂梯度等条件对rPET瓶片中非挥发性有机物测定的影响。研究结果显示：以0.2 g的rPET瓶片溶于10 mL六氟异丙醇中,20 mL甲醇作为沉淀溶剂、氮吹去除溶剂的前处理方式,以甲醇－0.1%甲酸水体系作为流动相梯度洗脱,采用数据依赖型采集（DDA）模式进行测试。此时获得方法的回收率为66.0%～80.4%,相对标准偏差（RSD）均不高于5.1%,表现出较好的稳定性和可重复性。采用质谱数据库和二级谱图定性,通过结构类似的化合物进行半定量,rPET瓶片中共检出30种非挥发性有机化合物,含量范围为0.038～4.92 mg/kg。检出物质包括环状和线型寡聚物、助剂副产物或降解产物和污染物等非有意添加物27种,其余3种可能是有意添加物。利用建立的非靶向筛查方法以及主成分分析（PCA）对两个不同地域厂家的24种rPET瓶片（rPET C和rPET N）进行检测,结果显示两组样品在正离子模式下有明显差异,检出差异物质15种;负离子模式下差异不明显。表明同类型但不同来源的rPET瓶片具有不同的差异物质。研究表明,所建立的UPLC－QTOF MS筛查方法具有准确可靠、简单、快速等优点,可有效用于食品接触rPET中非挥发性有机物的分析及安全评价工作     

马来酸酐接枝氢化苯乙烯-丁二烯嵌段共聚物增韧聚苯醚体系的韧性、亚微相态和流变性能

考察了氢化苯乙烯-丁二烯嵌段共聚弹性体(SEBS)及其马来酸酐接枝共聚物(SEBS-g-MA)增韧聚苯醚(PPO)体系。DSC谱图显示,PPO与SEBS的共混物仅有一个T_g,两者完全相容;PPO与SEBS-g-MA的共混物存在两个T_g,只能达到部分相容。力学性能研究表明,在PPO/SEBS体系中,基体中分散相SEBS的相界面模糊,无法引发基体银纹和剪切屈服,增韧PPO的效果有限;而部分相容的PPO/SEBS-g-MA共混物显示了增韧剂良好的相界面引发基体银纹和剪切屈服的作用,其缺口冲击强度在SEBS-g-MA质量分数为20%时达到1260J/m的超韧性。亚微相态显示,SEBS在PPO中呈现条形分散相的"海岛"结构;而SEBS-g-MA在基体中呈现网络结构。流变性能研究显示,PPO/SEBS共混物的表观粘度均高于PPO,并随SEBS的含量增加而变大;而PPO/SEBS-g-MA则完全相反。     

基于全链条的回收PET材料中非挥发性可迁移物的非靶向筛查及特征风险标志物的确定

基于超高效液相色谱－四极杆飞行时间质谱（UPLC－Q－TOF MS）对回收聚对苯二甲酸乙二醇酯（回收PET,rPET）全链条中回收碎片及由碎片造粒得到的粒料、瓶坯、瓶子4个阶段rPET样品进行溶解沉淀实验及模拟迁移试验,对样品中的潜在迁移物及迁移物进行非靶向筛查,得到包括PET寡聚体、润滑剂、漂洗剂在内的30种有意、非有意添加物。使用MS－DIAL（Mass spectrometry－data independent analysis software）软件对rPET不同生产阶段的产品标志物进行快速筛选,发现在粒料到瓶坯的加工过程中,生成了新的PET寡聚体;rPET碎片样品中标志物为脂肪醇聚氧乙烯醚,分析可能由漂洗过程引入。对比PET寡聚体的相对含量发现,rPET材料中环状寡聚体的相对含量高于线性寡聚体,其中第二系列环状二聚体的相对含量最高。在rPET加工过程中部分寡聚体及润滑剂的相对含量增加。最后通过TEST（Toxicity estimation software tool）软件预测潜在迁移物及迁移物的大鼠经口急性毒性、发育毒性和致突变性,采用Toxtree软件进行Cramer分级,PET环状寡聚体及酰胺类润滑剂均被分为Cramer Ⅲ级,毒性均高于线性寡聚体,应在rPET加工过程中引起关注。     

嵌段共聚物相容剂对聚合物共混体系力学性能影响的连续介观模拟

结合介观动力学方法和三维弹簧格子模型, 研究了嵌段共聚物相容剂对相容性较差的聚合物二元共混体系力学性能的影响. 在适当范围内不断增加嵌段共聚物相容剂的用量, 研究了相容剂含量对体系杨氏模数及拉伸强度的影响, 同时也对不同体系材料的破碎位点进行了分析. 结果表明, 未加入相容剂的二元共混体系在拉伸模拟中表现出较低的拉伸强度, 而适量添加相容剂可以显著提升材料的拉伸强度, 随着相容剂含量的增加, 共混体系的破碎位点会发生转移并最终改善材料的整体性能. 而相容剂的加入对体系杨氏模数的影响较小. 该连续模拟方法为关联聚合物复合体系的微观结构和宏观力学性能提供了一条高效的途径.     

嵌段共聚物相容剂对聚合物共混体系力学性能影响的连续介观模拟

结合介观动力学方法和三维弹簧格子模型,研究了嵌段共聚物相容剂对相容性较差的聚合物二元共混体系力学性能的影响.在适当范围内不断增加嵌段共聚物相容剂的用量,研究了相容剂含量对体系杨氏模数及拉伸强度的影响,同时也对不同体系材料的破碎位点进行了分析.结果表明,未加入相容剂的二元共混体系在拉伸模拟中表现出较低的拉伸强度,而适量添加相容剂可以显著提升材料的拉伸强度,随着相容剂含量的增加,共混体系的破碎位点会发生转移并最终改善材料的整体性能.而相容剂的加入对体系杨氏模数的影响较小.该连续模拟方法为关联聚合物复合体系的微观结构和宏观力学性能提供了一条高效的途径.     

含刚性链节和脲端基聚醚增韧剂改性环氧树脂的研究———反应活性及力学性能

合成了一系列既含环氧丙烷聚醚（ＰＰＧ）柔性间隔基、又含刚性介晶结构单元的端脲基活性改性剂（ＬＣＥＵＰＰＧ），并对其改性环氧树脂Ｅ ５１／双氰双胺（Ｅ ５１／ｄｉｃｙ）体系的固化反应活性、改性剂含量对增韧体系动态力学性能及冲击性能的影响进行了研究．结果表明：ＬＣＥＵＰＰＧ的加入对固化体系具有明显的增韧作用，冲击强度提高了３～７倍；其对Ｅ ５１／ｄｉｃｙ固化反应具有明显的促进作用，可使固化反应表观活化能（Ｅａ）降低５０～７０ＫＪ／ｍｏｌ、固化温度降低３０～４０℃；体系的玻璃化转变温度（Ｔｇ）略有下降，但模量基本不降低或略有升高；β 转变向低温方向移动．     

环氧树脂／PEG／OMMT杂化体的合成及性能研究

以三乙基苄基氯化铵为催化剂,制备了环氧树脂E-44和聚乙二醇（polyglycol,PEG）的杂化体A;将接枝了马来酸酐的PEG与E-44共混,制备了杂化体B。比较杂化体A和杂化体B的性能及其对E-44的增韧效果。结果表明,杂化体A具有水溶性和较好的表面活性,且对E-44具有优异的增韧效果,加入质量分数40％的杂化体A可使E-44的冲击强度提高203％,适量的有机蒙脱土（organic montmorillonite,OMMT）可有效弥补杂化体A增韧时所引起的剪切强度下降。杂化体B中的PEG与E-44几乎没反应,但PEG会参与其固化反应,从而显著提高E-44的韧性,只是效果不如杂化体A。     

双酚A型氰酸酯树脂/端羧基丁腈橡胶共混物的结构与性能

用液体端羧基丁腈橡胶（CTBN）对双酚A型氰酸酯树脂（BCE）进行增韧改性,用红外光谱、扫描电子显微镜,动态力学能谱仪等分析手段表征共混物的微观结构,测定其力学性能、耐热性等.结果表明,CTBN增韧BCE树脂体系可形成典型的海岛状共混结构;当平均粒径为2～3μm时,增韧效果最佳;当CTBN加入10份时,冲击强度提高150%,最大失重率所对应的温度只下降3.5℃;动态力学性能分析证明BCE/CTBN共混物是一个多相体系,存在橡胶CTBN相、BCE相和以BCE为主的BCE/CTBN共聚相、以CTBN为主的BCE/CTBN共聚相.     

Rheology,morphology and tensile properties of thermotropic liquid crystalline polymer/polypropylene in‐situ composites

Blends of various grades of polypropylene (PP) with a thermotropic liquid crystalline polymer (TLCP), namely a copolymer of p‐benzoic acid and ethylene terephthalate (60/40 mole ratio) were prepared as extruded films. A thermoplastic elastomer styrene (ethylene‐butylene) styrene (SEBS) was used as a compatibilizer. Melt viscosities of all specimens were measured using a plate‐and‐plate rheometer with oscillating mode in the shear rate region of 1 ‐ 200 rad/s. Addition of SEBS compatibilizer resulted in an increase of the blend viscosity. Observation of the blend morphology revealed an improvement of TLCP dispersion. The TLCP fiber aspect ratio (length to diameter) in the extruded film also increased after addition of SEBS. As a result, the film modulus in extrusion direction was enhanced. The tensile strength of the film specimen was also increased due to an improvement of interfacial adhesion.     

A study of PP/PET composites: Factorial design,mechanical and thermal properties

Due to the economic importance of polypropylene (PP) and polyethylene terephthalate (PET), and the large amount of composites made with PP matrix and recycled PET as reinforcing material; an investigation was performed regarding the mechanical and thermal behavior of PP composites containing recycled polyethylene terephthalate fibers (rPET). Interfacial adhesion between the two materials was achieved by adding a compatibilizer, maleic anhydride grafted polypropylene, PP-g-MA. Mechanical behavior was assessed by tensile, flexural, impact and fatigue tests, and thermal behavior by HDT (Heat Deflection Temperature). Fractured surfaces and fiber were investigated by scanning electron microscopy. Multiple regression statistical analysis was performed to interpret interaction effects of the variables. Tensile strength, tensile modulus, flexural strength, flexural modulus and HDT increased after rPET fiber incorporation while strain at break, impact strength and fatigue life decreased. Addition of compatibilizer increased tensile strength, flexural strength and flexural modulus, fatigue life and HDT while tensile modulus, strain at break and impact strength decreased. However, at low fiber content, the impact strength increased, probably due to nucleation effects on PP.     

Long-Range Processing Correlation and Morphological Fractality of Compatibilized Blends of PS/ HDPE/ SEBS Block Copolymer

Summary: Processing and compatibilization effects of a commercially available styrene/ ethylene-butylene/ styrene (SEBS) compatibilizer on the morphological structure, rheological and mechanical properties of blends of polystyrene (PS) and high density polyethylene (HDPE) were investigated. The rheological behaviour of the blends melt during processing was followed by measuring torque; extrusion capacity output and melts back-pressure in a twin screw extruder. The processing parameters were decreased with the HDPE content. The results show that SEBS compatibilizer can yield compatibilization by substantially reducing torque and increasing the back-pressure. However, the Hurst indices of melt processing parameters are increased with compatibilization. Near-infrared spectra had been described by the Hurst index H_NIR which is then related to HDPE content in the blends. The correlation between the blend compositions, morphological structure, mechanical and rheological properties and processing parameters was established and discussed on base of correlation with the fractal indices obtained from the SEM microphotographs of PS/HDPE/SEBS blends.     

The effect of various compatibilizers on thermal,mechanical, and morphological properties of polystyrene/polypropylene blends

The effects of various compatibilizers on thermal, mechanical and morphological properties of 50/50 polypropylene/polystyrene blends were investigated. Various compatibilizers, polystyrene-(ethylene/butylenes/ styrene) (SEBS), ethylene vinyl acetate (EVA), polystyrene-butylene rubber (SBR) and blend of compatibilizers SEBS/PP-g-MAH, EVA/PP-g-MAH, and SBR/PP-g-MAH were used. Differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, scanning electron microscopy, microhardness, and Izod impact strength were adopted. It was found that the influence of various compatibilizers was appeared on all the properties studied. The properties of the blends compatibilized with SEBS, EVA, and SBR are very distinct from those of blends compatibilized with blend of compatibilizers. Results show that compatibilized blends with the blend of compatibilizers EVA/PP-g-MAH, SBR/PP-g-MAH, and SEBS/PP-g-MAH or SBR were relatively more stable than the uncompatibilized blend and blend compatibilized with SEBS or EVA. The compatibilizer does not only reduce the interfacial tension or increase the phase interfacial adhesion between the immiscible polymers, but greatly affects the degree of crystallinity of blends.

     

Effects of different types of polyethylene on the morphology and properties of recycled poly(ethylene terephthalate)/polyethylene compatibilized blends

Recycled poly(ethylene terephthalate) (R‐PET) was blended with four types of polyethylene (PE), linear low density polyethylene (LLDPE; LL0209AA, Fs150), low density polyethylene (LDPE; F101‐1), and metallocene‐LLDPE (m‐LLDPE; Fv203) by co‐rotating twin‐screw extruder. Maleic anhydride‐grafted poly(styrene‐ethylene/butyldiene‐styrene) (SEBS‐g‐MA) was added as compatibilizer. R‐PET/PE/SEBS‐g‐MA blends were examined by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and mechanical property testing. The results indicated that the morphology and properties of the blends depended to a great extent on the miscibility between the olefin segments of SEBS‐g‐MA and PE. Due to the proper interaction between SEBS‐g‐MA and LDPE (F101‐1), most SEBS‐g‐MA, located at the interface between two phases of PET and LDPE to increase the interfacial adhesion, lead to better mechanical properties of R‐PET/LDPE (F101‐1) blend. However, both the poor miscibility of SEBS‐g‐MA with LLDPE (LL0209AA) and the excessive miscibility of SEBS‐g‐MA with LLDPE (Fs150) and m‐LLDPE (Fv203) reduced the compatibilization effect of SEBS‐g‐MA. DSC results showed that the interaction between SEBS‐g‐MA and PE obviously affected the crystallization of PET and PE. DMA results indicated that PE had more influence on the movement of SEBS‐g‐MA than PE did. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluation of the SEBS copolymer in the compatibility of PP/ABS blends through mechanical,thermal, thermomechanical properties,and morphology

Polypropylene (PP) blends with acrylonitrile-butadiene-styrene (ABS) were prepared using the styrene-ethylene-butylene-styrene copolymer (SEBS) as a compatibilizing agent. The blends were prepared in a co-rotational twin-screw extruder and injection molded. Torque rheometry, Izod impact strength, tensile strength, heat deflection temperature (HDT), differential scanning calorimetry, thermogravimetry, and scanning electron microscopy properties were investigated. The results showed that there was an increase in the torque of PA6/ABS blends with SEBS addition. The PP/ABS/SEBS (60/25/15%) blend showed significant improvement in impact strength, elongation at break, thermal stability, and HDT compared with neat PP. The elastic modulus and tensile strength have not been significantly reduced. The degree of crystallinity and the crystalline melting temperature increased, indicating a nucleating effect of ABS. The PP/ABS blends compatibilized with 12.5% and 15% SEBS presented morphology with well-distributed fine ABS particles with good interfacial adhesion. As a result, thermal stability has been improved over pure PP and the mechanical properties have been increased, especially impact strength. In general, the addition of the SEBS copolymer as the PP/ABS blend compatibilizer has the advantage of refining the blend's morphology, increasing its toughness and thermal stability, without jeopardizing other PP properties.     

Reactive compatibilization of poly(styrene-Co-maleic anhydride)/poly(phenylene oxide) blends

Primary amine terminated polystyrene (PS-NH₂), with Mn=12,000 g/mol and Mw=23,000 g/mol, was applied as a reactive compatibilizer for poly(styrene-co-maleic anhydride)/poly(phenylene oxide) (SMA/PPO) blends, in which both an impact modifier for the continuous SMA phase, viz. ABS, and the dispersed PPO phase, viz. SEBS, was incorporated. During melt blending, SMA-g-PS copolymers are generated at the interface between the SMA/ABS and the PPO/SEBS phases. The addition of 10 wt % of the reactive PS-NH₂ compatibilizer to a SMA/ABS/PPO/SEBS 30/30/30/10 blend results in a more significant refinement of the dispersed PPO/SEBS particles than 10 wt % of a commercially available, bulky PS-graft-PMMA copolymer with Mn=45,300 and Mw=293,400 g/mol. In addition, PS-NH₂ gives a more pronounced enhancement of the yield stress, the stress at break and the notched Izod Impact than the PS-g-PMMA. On the other hand, the elongation at break is higher in the case of the non-reactive PS-g-PMMA. It was demonstrated that surface imperfections, probably introduced by an observed strongly elastic character due to partial crosslinking of the SMA/ABS phase by difunctional H₂N-PS-NH₂, are responsible for the lower elongation at break for the PS-NH₂ based blends.     

Improvement of Impact Strength of Polylactide Blends with a Thermoplastic Elastomer Compatibilized with Biobased Maleinized Linseed Oil for Applications in Rigid Packaging

This research work reports the potential of maleinized linseed oil (MLO) as biobased compatibilizer in polylactide (PLA) and a thermoplastic elastomer, namely, polystyrene-b-(ethylene-ran-butylene)-b-styrene (SEBS) blends (PLA/SEBS), with improved impact strength for the packaging industry. The effects of MLO are compared with a conventional polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene-graft-maleic anhydride terpolymer (SEBS-g-MA) since it is widely used in these blends. Uncompatibilized and compatibilized PLA/SEBS blends can be manufactured by extrusion and then shaped into standard samples for further characterization by mechanical, thermal, morphological, dynamical-mechanical, wetting and colour standard tests. The obtained results indicate that the uncompatibilized PLA/SEBS blend containing 20 wt.% SEBS gives improved toughness (4.8 kJ/m²) compared to neat PLA (1.3 kJ/m²). Nevertheless, the same blend compatibilized with MLO leads to an increase in impact strength up to 6.1 kJ/m², thus giving evidence of the potential of MLO to compete with other petroleum-derived compatibilizers to obtain tough PLA formulations. MLO also provides increased ductile properties, since neat PLA is a brittle polymer with an elongation at break of 7.4%, while its blend with 20 wt.% SEBS and MLO as compatibilizer offers an elongation at break of 50.2%, much higher than that provided by typical SEBS-g-MA compatibilizer (10.1%). MLO provides a slight decrease (about 3 °C lower) in the glass transition temperature (T_g) of the PLA-rich phase, thus showing some plasticization effects. Although MLO addition leads to some yellowing due to its intrinsic yellow colour, this can contribute to serving as a UV light barrier with interesting applications in the packaging industry. Therefore, MLO represents a cost-effective and sustainable solution to the use of conventional petroleum-derived compatibilizers.     

Compatibilizing effect of functionalized polystyrene blends: a study of morphology,thermal, and mechanical properties

Polystyrene (PS), being an amorphous polymer is immiscible with other polymers. To engender miscible blends, PS has been functionalized with an active amino‐functional group on the molecular chains of PS to yield amino‐substituted polystyrene (APS), which serves as a reactive compatibilizer. The compatibilization effect of amino functionalized polystyrene on the rubber toughening was explored and results were compared in terms of morphology, thermal, and mechanical properties of PS/SEBS‐g‐MA versus APS/SEBS‐g‐MA blends. In addition, the effect of rubber content on the blend morphology and mechanical properties were investigated. An appreciable change in the thermal stability of APS blends in comparison with PS blend has been probed. A marked correlation has been observed between phase morphology and thermal stability. Use of APS produced the compatibilized blends which render improved blend morphology, enhanced thermal and mechanical properties. Optimal thermal, morphological and mechanical profiles were depicted by 20‐wt% APS blend. Copyright © 2008 John Wiley & Sons, Ltd.     

Impact‐modified polypropylene/vermiculite nanocomposites

Impact‐modified polypropylene (PP)/vermiculite (VMT) nanocomposites toughened with maleated styrene–ethylene butylene–styrene (SEBS‐g‐MA) were compounded in a twin‐screw extruder and injection‐molded. VMT was treated with maleic anhydride, which acted both as a compatibilizer for the polymeric matrices and as a swelling agent for VMT in the nanocomposites. The effects of the impact modifier on the morphology and the impact, static, and dynamic mechanical properties of the PP/VMT nanocomposites were investigated. Transmission electron microscopy revealed that an exfoliated VMT silicate layer structure was formed in ternary (PP–SEBS‐g‐MA)/VMT nanocomposites. Tensile tests showed that the styrene–ethylene butylene–styrene additions improved the tensile ductility of the (PP–SEBS‐g‐MA)/VMT ternary nanocomposites at the expense of their tensile stiffness and strength. Moreover, Izod impact measurements indicated that the SEBS‐g‐MA addition led to a significant improvement in the impact strength of the nanocomposites. The SEBS‐g‐MA elastomer was found to be very effective at converting brittle PP/VMT organoclay composites into tough nanocomposites. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2332–2341, 2003