辐射接枝法生产离子交换纤维的进展

介绍了辐射接枝生产离子交换纤维的主要方法 :共辐射接枝法、无氧预辐射接枝法和有氧预辐射接枝法。比较了这些方法的优缺点 ,指出有氧预辐射接枝更适合于工业化生产。对今后辐射接枝生产离子交换纤维的发展进行了展望     

聚丙烯接枝改性综述

本文从能量获取方式介绍了聚丙烯(PP)接枝改性的几种方法,其中包括紫外光接枝法、等离子接枝法、辐射接枝法、熔融接枝法、超临界接枝法、臭氧化接枝法等,并且介绍了各种不同接枝方法的优缺点.并且对聚丙烯接枝改性的发展方向进行了介绍.     

聚丙烯接枝改性研究进展

文章对聚丙烯(PP)接枝改性的几种方法及其研究进展进行了综述,其中包括溶液法接枝、悬浮法接枝、熔融法接枝、固相法接枝、辐射法接枝以及超临界CO2法接枝等,并且对各种不同接枝方法的优劣性进行了讨论,指出固相法接枝和超临界CO2法接枝是相对环保、实用的聚丙烯接枝改性方法。并且对聚丙烯接枝改性的发展方向进行了展望。     

无机微粒表面接枝聚合改性进展

讨论了表面接枝改性机理,综述了"接枝到"(Grafting to)法和"由表面接枝"(Grafting from)法以及其它表面接枝改性方法的研究进展。     

聚丙烯固相接枝马来酸酐改性研究

采用固相法以马来酸酐对聚丙烯粒料(粒径为2.7 mm)进行接枝改性,研究了反应条件对接枝率和接枝效率的影响,通过化学分析、红外光谱、平衡转矩等对接枝聚丙烯进行了表征。结果表明,马来酸酐成功接枝于聚丙烯上,最大接枝率可达2.2%;马来酸酐接枝聚丙烯平衡转矩明显大于接枝空白样,接枝率的大小对平衡转矩影响不大。     

聚烯烃热塑性弹性体POE官能化及其应用

聚烯烃热塑性弹性体（POE）的非极性限制了它的进一步应用,为了扩大其使用领域,对POE官能化引起关注。将POE作为接枝机体树脂,利用其支化度比较高、容易形成接枝点来获得较高的接枝率;由于其侧链相对较大,有可能降低大分子自由基之间碰撞的几率,从而减轻凝胶化程度,得到具有良好流动性的接枝树脂。本文综述了聚烯烃热塑性弹性体POE官能化几种方法,包括在有机过氧化物引发剂存在下的熔融接枝法、裂解引发接枝、机械力引发接枝、复合引发接枝等等,并对其产物的应用进行概括。     

聚丙烯的绿色环保固相接枝法研究进展

随着国家对化工生产中的污染问题日益重视,传统的聚丙烯熔融接枝和溶液接枝的工业化生产面临巨大的考验,而发展绿色环保的聚丙烯固相接枝法成为研究的热点之一.从热引发、光引发、等离子体引发、辐射引发、其他方法等五个方面综述了绿色环保的聚丙烯固相接枝的研究进展,并分析了各种固相接枝法的优缺点,最后对绿色环保的聚丙烯固相接枝法的前...     

配方和工艺对熔融法天然橡胶接枝马来酸酐结构的影响

研究配方和工艺对熔融法天然橡胶接枝马来酸酐(NR-g-MAH)接枝率和接枝效率的影响。结果表明:加入1,2-聚丁二烯(1,2-PB)对提高NR-g-MAH接枝率具有明显效果;马来酸酐用量为5份、1,2-PB用量为6份、引发剂DCP用量为0.2份、反应温度为135℃、转子转速为50r·min-1、反应时间为4min时,NR-g-MAH的接枝率和接枝效率较高。     

双螺杆挤出机液体进料工艺在改性塑料中的应用

采用双螺杆液体进料接枝法合成聚丙烯接枝丙烯酸共聚物,研究双螺杆液体进料接枝共聚方法对接枝物接枝率大小及性能的影响,采用红外光谱对接枝物结构进行分析。结果表明：用恒流泵在液体加料口匀速进料,当调节恒流泵转速8．0时,接枝率最高：6．254％。     

接枝支链结构对聚乙烯多单体接枝共聚物结晶性能的影响

采用固相接枝法合成聚乙烯(PE)与甲基丙烯酸缩水甘油酯、苯乙烯、丙烯酸丁酯的固相接枝共聚物(PETM),利用差示扫描量热法、X射线衍射和偏光显微镜等测试手段研究了接枝支链对接枝共聚物的结晶过程的影响,并对接枝共聚物的X射线衍射峰进行分峰,计算接枝共聚物的晶胞参数。结果表明:接枝支链并没有改变PE的晶型,只是充当异相成核剂的作用并阻碍PE的晶体生长;受接枝支链影响,PE中存在不完善的结晶,PETM的结晶度比PE低。     

Determination methods of the grafting yield in glycidyl methacrylate‐grafted ethylene/propylene/diene rubber (EPDM‐g‐GMA): Correlation between FTIR and 1H‐NMR analysis

A normalized and universally applicable calibration function for the Fourier‐transformed infrared (FTIR) quantification of the glycidyl methacrylate (GMA) grafting yield in polymers of known compositions having ethylene block sequences was established. The ¹H nuclear magnetic resonance (¹H‐NMR) spectroscopy results achieved on different GMA‐grafted ethylene/propylene/diene rubber (EPDM‐g‐GMA) and ethylene/GMA copolymers were correlated to their FTIR data to calibrate the relative determination of the FTIR method. Both direct and indirect standardization approaches were followed and evaluated. The calibration deduced was used to investigate the free radical grafting reaction of GMA on EPDM rubber in the melt phase. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2616–2624, 1999     

亚甲基丁二酸接枝LDPE

利用反应挤出技术制备了低密度聚乙烯(LDPE)/亚甲基丁二酸接枝物。研究了引发剂种类及用量对接枝率和接枝物熔体流动速率(MFR)的影响。结果表明：采用引发剂L-101的接枝率最高,添加ω(L-101)为0．2％时．接枝率即可接近90％,接枝的同时伴有交联,接枝物的MFR从LDPE的16g／10min下降到2g／10min左右。     

甲基丙烯酸缩水甘油酯接枝聚烯烃及在塑料改性中的应用进展

简单介绍了甲基丙烯酸缩水甘油酯熔融接枝聚烯烃的第二单体、引发剂、反应温度和反应时间等因素对接枝反应的影响,探讨了接枝率的测定方法及接枝聚烯烃在塑料改性中的应用等。     

GMA接枝聚烯烃及在塑料改性中的应用进展

简单介绍了甲基丙烯酸缩水甘油酯(GMA)熔融接枝聚烯烃的第二单体、引发剂、反应温度和反应时间等因素对接枝反应的影响,接枝率的测定方法及接枝聚烯烃在塑料改性中的应用等。     

Biofouling reduction of EPDM by radiation-assisted modification for water environment applications

Ethylene propylene diene elastomer (EPDM) harbors diverse microbiota that form biofilms. Such biofilms may contaminate water and can increase drag force impacting the hydrodynamic performance of a ship, once it is used as fenders. Here, the EPDM surface is modified by radiation-assisted grafting to prevent biofilm formation. Three different monomers, namely, methacrylic acid (MAA), isodecyl methacrylate (IDM), and lauryl methacrylate (LMA), are grafted on EPDM. The modified surfaces are characterized by Fourier transform infrared (FTIR) spectroscopy, surface wettability, mechanical and dynamic mechanical properties (DMA), and scanning electron microscopy (SEM). The modified surfaces are subjected to biofouling by prominent biofilm adherents, that is, Pseudomonas aeruginosa and Klebsiella pneumoniae. The standard plate count and resazurin fluorescence assays are performed to observe the microbial load on these surfaces. The MAA-grafted EPDM, which is hydrophilic in nature, shows a considerable decrease in bacterial adhesion compared to pure EPDM, but for IDM and LMA-grafted EPDM, it is the opposite. The deterioration of the surface with bacteria by environmental scanning electron microscopy (ESEM) supports the findings. The tensile property of the modified EPDM is observed to be within satisfactory limits. After such modification, the EPDM is expected to expand its application.     

利用反应挤出的聚丙烯熔融接枝改性

系统简介了聚丙烯熔融接枝体系的组成、机理及实现熔融接枝的反应挤出技术。介绍了聚丙烯接枝物的表征和应用状况，并指出了熔融接枝体系中存在的问题。     

三元乙丙橡胶与尼龙树脂的增容共混

以甲基丙烯酸缩水甘油酯为接枝单体、过氧化二异丙苯为引发剂对三元乙丙橡胶（EPDM）进行熔融接枝。用傅里叶红外光谱（FTIR）对接枝产物进行了表征,分析测试了共混硫化胶的力学性能和微观结构。结果表明,随着共混体系中接枝EPDM用量的增加,EPDM与尼龙树脂的相容性不断改善,尼龙颗粒作为分散相在EPDM中分散得更加均匀和细致化,共混硫化胶的力学性能得到进一步提高,尼龙树脂原位生成的短纤维可明显提高共混硫化胶的撕裂强度,同时使其保持了弹性体高伸长率的特性。     

GMA熔融接枝SBS的研究

研究了活性单体甲基丙烯酸环氧丙酯（GMA）对苯乙烯一丁二烯一苯乙烯嵌段共聚物（SBS）的接枝，制备成SBS—g—GMA接枝物，用红外光谱对其进行了表征，并用化学滴定方法测定其接枝率及接枝物的凝胶含量；考察了单体GMA和引发荆DCP的用量以及停留时间对接枝率的影响。     

PP-g-GMA的制备及其改性PP/PA6合金性能

采用双螺杆熔融接枝的方法,在引发剂过氧化二异丙苯(DCP)作用下,将甲基丙烯酸缩水甘油酯(GMA)和共单体苯乙烯(St)接枝到聚丙烯(PP)上。通过傅立叶变换红外光谱仪确定了接枝物的生成,采用酸碱滴定法测定了接枝率。探讨了GMA,St,DCP不同用量对PP接枝物的接枝率和熔体流动速率的影响,并将接枝产物PP–g–(St–co–GMA)加入PP/尼龙6(PA6)的合金中,通过注塑成型样条,测定其力学性能,并观察微观结构。结果表明,St的加入能够提高接枝率,抑制副反应的发生。在PP/PA6合金中加入接枝物PP–g–(St–co–GMA),其拉伸强度可提高46.45%,弯曲强度可提高32.47%,但对冲击强度影响不大。     

Study of multi‐monomer melt‐grafting onto polypropylene in an extruder

Free‐radical melt‐grafting of the dual‐monomer systems glycidyl methacrylate–styrene (GMA‐St) and hydroxyethyl methacrylate–styrene (HEMA‐St) onto polypropylene (PP) has been studied using a single‐screw extruder. For single monomer grafting systems, degradation of PP was unavoidable and deterioration of the mechanical properties of the grafted PP subsequently occurred because of β‐scission of PP chains during the free‐radical melt‐grafting process. However, for the dual‐monomer systems, it is shown that the addition of styrene as a comonomer can significantly enhance the GMA or HEMA grafting levels on PP and reduce the extent of β‐scission of PP backbone. It has been found that the grafting degree of dual‐monomer melt‐grafted PP, such as PP‐g‐(GMA‐co‐St) or PP‐g‐(HEMA‐co‐St), is about quadruple that of single‐monomer grafted PP for the same monomer and dicumyl peroxide concentrations. Moreover, the melt flow rate of the dual‐monomer grafted PP is smaller than that of the unmodified PP. Hence, PP not only was endowed with higher polarity, but also kept its good mechanical properties. © 2000 Society of Chemical Industry