回收PET瓶片/接枝PE反应共混物的形态及性能

利用有反应活性的各种接枝聚乙烯(PE)作为回收聚对苯二甲酸乙二酯(PET)瓶片的改性剂,使接枝PE上的活性酐基与PET的端羟基在不同的挤出设备中熔融反应,制备相分散均匀、力学性能较好的PET基工程塑料.结果表明,挤出设备的选择对混合效果影响较大,缩聚型反应挤出机和双螺杆挤出机比普通单螺杆挤出机具有更优良的混合效果;各种接枝PE的改性效果优劣次序是:马来酸酐接枝线型低密度聚乙烯,马来酸酐接枝低密度聚乙烯,马来酸酐接枝高密度聚乙烯;接枝PE添加质量分数为20%时,可大幅度提高反应共混物的冲击性能.     

回收聚酯瓶制备PET/PE合金及其应用

应用自制的接枝共聚相容剂将回收PET分别与韩国SK公司生产的瓶盖专用LLDPE和回收LLDPE共混改性制备成PET/PE合金,对2种合金的微观结构和力学性能进行了研究,SEM表明:2种合金性能相差不大,相容剂效果良好。其中用回收LLDPE制作的合金,其材料的拉伸强度为37.76 MPa,断裂伸长率达到470.0%,缺口冲击强度为18.3 kJ/m2,可以满足注塑、挤出等加工工艺要求,同时该合金可加工成塑料管材、塑料托盘和编织袋。另外,制备PET/PE合金不需要干燥处理,加工合金也不需要干燥。     

基于PE/EPDM胶粉的共混性能研究

通过密炼共混法成功制备了聚乙烯（PE）/废旧三元乙丙橡胶（EPDM）胶粉的热塑性弹性体,研究了不同PE/EPDM共混比和不同相容剂对热塑性弹性体力学性能的影响。实验结果表明：随PE用量增加,拉伸强度、100%定伸应力、硬度提高,拉断伸长率降低。在PE用量不变的条件下,加入相容剂可改善PE/废旧EPDM胶粉热塑性弹性体的基本力学性能,其中随着相容剂氯化聚乙烯（CPE）与马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS-g-MA）用量的增加,拉伸强度、100%定伸应力、拉断伸长率和硬度提高;而以马来酸酐接枝乙丙橡胶（EPDM-g-MA）为相容剂时,除拉断伸长率外,拉伸强度、100%定伸应力与硬度则呈现相反的趋势,其随EPDM-g-MA用量增多而降低。     

多组分HDPE的HDPE /PA6共混合金性能特征

摘 要：采用熔融法制备了高密度聚乙烯（HDPE）与马来酸酐（MAH）接枝物（HDPE-g-MAH）,并以此接枝物制备了 HDPE-g-MAH/PA6共混合金,通过调整引发剂过氧化二异丙苯（DCP）和马来酸酐（MAH)的用量来控制接枝率,并研究该共混合金的性能与接枝率之间的关系。结果表明：HDPE-g-MAH/PA6共混合金的力学性能、耐热性等均较纯高密度聚乙烯有很大提高,当HDPE:PA6:MAH:DCP份数比例为60:40:1:0.3时,共混合金表现出较佳的性能。     

增加聚烯烃共混物界面粘结力的研究

在加工设备中制备聚乙烯、聚丙烯树脂的马来酸酐(MAH)接枝共聚物(PE-g-MAH,PP-g-MAH)。用偏光显微镜、相差显微镜及扫描电镜研究了PP-g-MAH及PP共混物的形态、分散状态与相界面。考察了PE-g-MAH/PET,PE/PET复合薄膜的剥离强度及PE-g-MAH/CaCO_3,PE/CaCO_3共混物的力学性能。所有结果均表明聚烯烃马来酸酐接枝物可显著增加聚烯烃共混物中组分间的相容性和界面粘结力,并讨论了其机理。     

聚烯烃弹性体与马来酸酐的熔融接枝

以双螺杆挤出机作为反应器，比较了聚烯烃弹性体（POE），线性低密度聚乙烯（LLDPE）与马来酸酐（MAH）的熔融接枝反应。尽这两种树脂具有相近的支化度，但由于POE树脂的大支链对大分子自由基之间的偶合反应具有抑制作用，所以，POE/MAH接枝体系的接枝率明显高于LLDPE／MAH接枝体系，而且接枝产物保持了较好的流动性；酸酐在POE树脂上的接枝率随过氧化物和接枝单体用量的增加而增大。接枝树脂可以明显提高PE与铝之间的粘接强度。     

功能化聚乙烯蜡的制备与表征

用溶液接枝法制备了马来酸酐（MAH）和马来酸酐／苯乙烯（St）双单体接枝的功能化聚乙烯蜡（PEW），考察了反应时间、温度、引发剂、单体用量对产物接枝率的影响。结果表明，接枝改性的最佳条件为温度110－120℃，反应时间2h，原料质量比为m(PEW)/m(MAH)/m(BPO)r=100/4/2/0.3。用傅立叶红外光谱和差示扫描量热分析表征了接枝产物的结构。     

聚乙烯-尼龙共混材料的相容性及性能研究

考察了不同种类和含量的相容剂对聚乙烯(PE)/尼龙(PA)两相共混物的熔融结晶行为、两相形貌和力学性能的影响。结果表明：PE接枝马来酸酐(PE-g-MAH)和POE接枝马来酸酐(POE-g-MAH)都使得PE和PA的结晶峰相互靠近,并且随着含量增加,两者的熔融峰呈现融合的趋势。两种接枝物都能使得共混物中PA6团聚颗粒的尺寸减小,孔洞减少,相界面模糊。PE接枝马来酸酐和POE接枝马来酸酐都能提高共混材料的拉伸强度和冲击强度。     

不同引发剂对PE熔融接枝MAH的影响

利用熔融反应挤出技术,研究了不同引发剂对聚乙烯接枝马来酸酐的影响。结果表明,DCP比较适合作为PE熔融接枝马来酸酐的引发剂,PE-g-MAH的接枝率随着DCP的用量增加而增加,接枝物的熔体流动速率（MFR）刚好相反,这是因为PE在接枝反应中存在交联的情况。     

EVA-g-MAH的制备及在聚合物共混相容中的应用

采用溶液接枝法合成得到乙烯-乙酸乙烯酯接枝马来酸酐聚合物（EVA-g-MAH）,利用核磁共振仪和红外光谱仪对产物进行分子链结构分析,结果表明：马来酸酐已成功接枝在EVA主链与酯基相连的叔碳原子上。通过调节马来酸酐（MAH）与EVA中乙酸乙烯酯（VA）单元的投料比,得到了不同接枝率（摩尔分数4.87%~12.3%）的产物。以EVA-g-MAH接枝共聚物为相容剂,通过聚合物加工制备了高密度聚乙烯（HDPE）/聚碳酸酯（PC）/EVA-g-MAH共混物,利用SEM对样品脆断面表面形貌进行对比观察,验证了EVA-g-MAH是HDPE/PC共混聚合物的良好相容剂。最后,研究了EVA-g-MAH对尼龙（PA6）/EVA共混物抗冲击强度的影响,当EVA-g-MAH加入质量分数为6%时对共混合金冲击强度提高最大。     

以回收聚酯为主要原料的PET/PE合金片材的研制及应用

以自制接枝共聚相容剂,将回收聚对苯二甲酸乙二醇酯(rPET)分别与全新线性低密度聚乙烯(PE-LLD)和回收聚乙烯(rPE-HD)共混改性,采用具备免干燥和侧面强制喂料系统的同向双螺杆挤出机熔融挤出rPET/PE合金片材(rPET与PE质量比为80:20),研究了不同厚度合金片材的性能.结果表明,使用rPET制备的合金...     

sPS/PET/SsPS/MTA复合材料的力学性能研究

用保持正常熔体插层法制备了新型的间规聚苯乙烯（sPS）／聚对苯二甲酸乙二酯（PET）／磺化间规聚苯乙烯（SsPS－H）及其锌盐（SsPS-Zn）／11－氨基酸改性蒙脱土（MTA）复合材料，该材料的综合力学性能较未加MTA材料显著提高。加入2份MTA时，sPS/PET/SsPS－H/MTA（质量比为85／15／4／2）和sPS/PET/SsPS－Zn/MTA（质量比为85／15／2／2）复合材料的冲击强度达到最大值，分别为15．6kJ/m^2和14．7kJ/m^2，约是纯sPS的3．5倍，是未加MTA材料的1．5倍。拉伸强度和弯曲强度比未填充材料都提高了约30MPa。     

热封温度对PET/Al/PE包装膜热封性能的影响

设计多种实验工况研究热封工艺参数对聚对苯二甲酸乙二酯(PET)/Al/聚乙烯(PE)复合薄膜热封强度的影响.结果表明,热封温度对热封强度的影响最为显著.在此基础上,采用扫描电子显微镜和拉伸破坏模式对热封区域表观判定,采用差示扫描量热法分析热封材料PE的热性能,并结合工程实际,确定PET/Al/PE有效热封温度为110～160℃.     

Phase structure and properties of poly(ethylene terephthalate)/high‐density polyethylene based on recycled materials

Blends based on recycled high density polyethylene (R‐HDPE) and recycled poly(ethylene terephthalate) (R‐PET) were made through reactive extrusion. The effects of maleated polyethylene (PE‐g‐MA), triblock copolymer of styrene and ethylene/butylene (SEBS), and 4,4′‐methylenedi(phenyl isocyanate) (MDI) on blend properties were studied. The 2% PE‐g‐MA improved the compatibility of R‐HDPE and R‐PET in all blends toughened by SEBS. For the R‐HDPE/R‐PET (70/30 w/w) blend toughened by SEBS, the dispersed PET domain size was significantly reduced with use of 2% PE‐g‐MA, and the impact strength of the resultant blend doubled. For blends with R‐PET matrix, all strengths were improved by adding MDI through extending the PET molecular chains. The crystalline behaviors of R‐HDPE and R‐PET in one‐phase rich systems influenced each other. The addition of PE‐g‐MA and SEBS consistently reduced the crystalline level (χ_c) of either the R‐PET or the R‐HDPE phase and lowered the crystallization peak temperature (T_c) of R‐PET. Further addition of MDI did not influence R‐HDPE crystallization behavior but lowered the χ_c of R‐PET in R‐PET rich blends. The thermal stability of R‐HDPE/R‐PET 70/30 and 50/50 (w/w) blends were improved by chain‐extension when 0.5% MDI was added. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚乙烯纺粘非织造布生产技术初探

采取高温纺丝和较低的侧吹风速度冷却,在聚丙烯(PP)纺粘生产线上生产聚乙烯(PE)纺粘非织造布,探讨了其生产工艺。结果表明:采用熔融指数(每10min)20g的PE为原料,选择纺丝温度250℃,侧吹风速度1.5～1.8m/s,侧吹风温度16～18℃,气流速度5000m/min,生产的PE纺粘非织造布单丝线密度2.16dtex,断裂强度0.68～1.61cN/dtex,断裂伸长率150%～165%。     

PET/PP共混改性研究

用合成的增容剂SEBS-g-MAH增容PP/PET共混体系,通过改变PET的含量和添加成核剂研究共混体系的力学性能的变化研究结果表明:随着PET含量的逐渐增加,冲击强度逐渐上升、拉伸强度逐渐下降;成核剂的加入对合金的强度有所改善;PET含量在20%～250%时体系的力学性能最佳.     

利用回收PET改性PC及其合金的研究

用已扩链增黏的回收聚对苯二甲酸乙二醇酯(PETr)及改性聚碳酸酯(PC),并通过熔融反应挤出制备了PC/PETr合金,采用相容剂乙烯-丙烯酸甲酯-甲基丙烯酸缩水甘油酯(E-MA-GMA)对PC/PETr合金进行增容。研究了相容剂用量对该合金拉伸强度、冲击强度和形态结构等的影响。结果表明,当m(PC)/m(PETr)为60:40,相容剂E-MA-GMA的质量分数为7.5%时,合金发生脆韧转变,缺口冲击强度达到58.76kJ/m2,同时拉伸强度达到49.96MPa。SEM观察发现,E-MA-GMA作为反应性增容剂,使得分散相PET颗粒变细。并且,随着E-MA-GMA用量的增加,PET在PC/PETr/E-MA-GMA共混体系中呈现出极不规则的近似条状或片状的形态结构,共混体系呈现出双连续相     

Calendar of events

The growth of Cu and Al films thermally evaporated onto polyethylene (PE) and polyethyleneterephthalate (PET) surfaces is followed in situ by XPS (X-ray Photoelectron Spectroscopy) and XAES (X-ray Auger Electron Spectroscopy) from the early submonolayer stages up to the completion of a metallic film. PE and PET surfaces were metallized first without any preliminary treatment. A second series of metallization experiments were run on the polymer surfaces but pretreated by a remote O₂ microwave plasma (2.45 GHz). These metal films have also been investigated by AFM (Atomic Force Microscopy) in air. Both metals are shown not to undergo chemical interaction with low surface energy polyolefin such as PE. While an abrupt interface is seen with A1, a diffusion of Cu into the bulk of the polymer is demonstrated. Large size clusters are evidenced by AFM in the initial steps of deposition. Cu and A1 are both shown to react with PET, but not in the same way. In the case of A1, the chemical interaction across the metal/polymer interface proceeds through an electron transfer from the metal toward the ester group O=C-O. With Cu, the chemical interaction is not so clearly evidenced and the Cu is found to diffuse into the PET. Oxygenated functionalities grafted by O₂ plasma on PE and PET are C-O, C=O, O-C-O, O-C=O, and O₂C=O. The roughness of the PE and PET surfaces is observed by AFM to increase with the plasma treatment. A metal-CO type complex is clearly observed with Al/treated PE and Cu/treated PET. No chemical interaction was observed at the Cu/treated PE interface.     

PET/PE/CB导电母料的研制

采用分离喂料技术在聚对苯二甲酸乙二酯(PET)/聚乙烯(PE)共混物中加入导电炭黑(CB),通过布斯往复式脉动挤出机熔融共混、挤出造粒,制备了综合性能较好的纤维级PET/PE/CB导电母料。研究发现,以PET/PE不相容共混物代替PET作母料的基体树脂,能以较低的CB用量获得较好的导电性能;CB的质量分数为15%时,母料的体积电阻率随PET用量的增加呈先减小后增大的趋势,在PET与PE的质量比为60∶40时,母料的体积电阻率最低。     

Structure and morphology of polyethylene/polypropylene in‐reactor alloys synthesized by spherical high‐yield Ziegler–Natta catalyst

A series of spherical polyethylene/polypropylene (PE/PP) in‐reactor alloys were synthesized with spherical high‐yield Ziegler–Natta catalyst by sequential multistage polymerization in slurry. The morphology of PE/PP alloy granule was evaluated by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results show PE/PP in‐reactor alloy with excellent morphology, high porosity, and narrow distribution of the particle size. The PE/PP in‐reactor alloys show excellent mechanical properties with good balance between toughness and rigidity. It was fractionated into five fractions by temperature‐gradient extraction fractionation, and every fractionation was analyzed by FTIR, ¹³C‐NMR, DSC, and WAXD. The PE/PP in‐reactor alloy was found to contain mainly five portions: PP, PE, segmented copolymer with PP and PE segment of different length, ethylene‐b‐propylene copolymer, and an ethylene–propylene random copolymer. The characteristic chain structure leads to good compatibility between the fractions of the alloy that shows a multiphase structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2075–2085, 2007