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聚烯烃接枝马来酸酐接枝率的测定—聚乙烯接枝 总被引:2,自引:1,他引:2
以非均相化学接枝法和红外光谱法相结合的方法绘制了定量校正曲线,可用于红外光谱法测定聚乙烯接枝马来酸酐的接枝率。该方法简便快速,准确可靠,重复性好。 相似文献
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马来酸酐苯乙烯双单体接枝聚丙烯的研究 总被引:16,自引:3,他引:13
研究了聚丙烯(PP)采用熔融法接枝马来酸酐(MAH)聚乙烯(St)双单体。实验表明,马来酸酐接枝率随其加入量增加而提高;添加两种单体时,马来酸酐添加量保持不变,马来酸酐接枝率随苯乙烯添加量增加而提高。经转矩流变,红外,热失重和差示扫描量热分析表明:马来酸酐,苯乙烯均与聚丙烯发生接枝反应,且有交联网络出现,因此推断出苯乙烯和马来酸酐预先发生交替共聚,共聚物与聚丙烯反应生成最终接枝物。接枝物应用于PP 相似文献
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聚丙烯紫外辐照气相接枝马来酸酐 总被引:7,自引:0,他引:7
在60℃、氮气气氛下,用低能量紫外辐照聚丙烯,进行聚丙烯的气相马来酸酐接枝。红外分析显示,在所选择的实验条件下,马来酸酐已经接枝到聚丙烯的分子链上。用重量法计算了马来酸酐的接枝率。实验结果表明,接枝聚丙烯(PP-g-MAH)的熔体流动速率和马来酸酐的接枝率随紫外辐射时间的增加而增加;紫外辐照时间保持不变,PP-g-MAH的溶体流动速率基本相同。 相似文献
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马来酸酐在炭黑表面接枝聚合的研究 总被引:5,自引:0,他引:5
研究了过氧化苯甲酰引发马来酸酐在炭黑表面的接枝聚合反应,探讨了反应时间、引发剂用量、接枝单体用量对接枝率的影响。结果表明,接枝率随反应时间的延长而增加,但2h后,接枝率增加不多;随引发剂用量的增加,接枝率呈上升趋势,但用量在15mg以后,接枝率趋于定值;随接枝单体用量的增加,接枝率直线上升。在本实验条件下,接枝率达到9%。通过接枝产物的X射线光电子能谱及红外分析可以证实,马来酸酐已接枝到炭黑表面。从光学显微图像分析结果可知,马来酸酐接枝改性对炭黑在聚合物基体中的分布和分散性能起到良好的改善作用。 相似文献
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本文以溶液法合成SBS接枝马来酸酐(MAH),控制不同反应时间、反应温度及MAH用量,得到不同接枝率的产物,用红外光谱及反滴定法分别定性定量表征了接枝率,结果显示:随反应时间、反应温度和马来酸酐用量的增加,接枝率呈不同增加趋势,其中反应温度对产物接枝率的影响最为显著。分别用NaOH、CaCl2、LaCl3将SBS接枝马来酸酐(sBS-g-MAH)离子化,得到SBS接枝马来酸盐离聚物。其耐溶剂性能、吸水性能及对极性基体的粘合性能随离子化而发生变化。离聚物呈现更好的吸水性能及耐溶剂性能。 相似文献
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马来酸酐在乙丙橡胶上的接枝共聚 总被引:4,自引:0,他引:4
马来酸酐在乙丙橡胶上的接枝共聚,用过氧化苯甲酰为引发剂的效果优于偶氮二异丁腈。研究了温度、马来酸酐用量和引发剂用量等对接枝率的影响。用红外光谱和薄层色谱证明了接枝物的存在。用接触角技术测定了接枝物的表面性能。 相似文献
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基于误差传递公式,对马来酸酐接枝聚丙烯(PP-g-MAH)接枝率的酸碱反滴定法测定建立了误差模型,讨论了取样量、HCl-异丙醇溶液浓度和接枝马来酸酐含量对接枝率测定误差的影响。实验室制备了PP-g-MAH,进行了红外光谱分析,分别以不同取样量、HCl-异丙醇溶液浓度对接枝物进行了接枝率测定;对比了不同马来酸酐含量PP-gMAH的接枝率测定误差。结果表明,马来酸酐已接枝在PP分子链上;PP-g-MAH的沉析及对KOH的包裹效应是接枝率测定误差大、再现性差的主要原因;酸碱滴定溶液浓度减小、取样量增大可减小测定误差,HCl-异丙醇溶液浓度为0.01 mol/L时可取得最小测定误差;所制备PP-g-MAH在HCl-异丙醇溶液浓度为0.01 mol/L、取样量为0.2 g时,测定接枝率的相对标准偏差为32%;所建误差模型可用于优化PP-g-MAH接枝率测试条件,减小测定误差。 相似文献
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聚乙烯蜡的微波辐射接枝反应研究 总被引:3,自引:2,他引:1
研究了聚乙烯蜡(PEW)与马来酸酐(MAH)的微波辐射接枝反应。考察了引发剂配比及种类、单体配比、辐射条件等对接枝反应的影响,通过正交实验应用多元线性拟合得出了酸值与接枝条件的经验式,制提了酸值为75mgKOH/g左右的接枝聚乙烯蜡(MPEW)。IR、DSC等测试结果表明,微波辐射确实能使PEW与MAH的接枝反应发生。 相似文献
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E. A. Abdel-Razik 《Polymer International》1996,40(3):207-211
Homogeneous graft copolymerization of dichlorodimethylsilane (DCDMS) onto cellulose acetate (CA) was carried out in acetone. The weight conversion, grafting percentage and grafting efficiency were determined as functions of the polymerization temperature and the concentrations of monomer and cellulose acetate. The IR and NMR data of the graft copolymers showed peaks characteristic of grafted chains. The order of the solvents used for increasing the grafting yield values was found as follows: cyclohexanone > ethyl acetate > dioxane, which is in accordance with their dielectric constants. Cellulose acetate previously oxidized by treatment with a mixture of oxalic acid and potassium dichromate when grafted with DCDMS gave low grafting yield values. The rate of copolymerization grafting of DCDMS onto CA was determined (Rp = 1.1 %min−1). The activation energy of the reaction between DCDMS and CA was calculated (1.32 kJ mol−1, 0.32 kcal mol−1). The mechanism of graft copolymerization of DCDMS onto CA is discussed. 相似文献
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This paper deals with photostabilization of low density polyethylene films (LDPE) grafted with the UV-stabilizer 2-hydroxy-4-(3-methacryloxy-2-hydroxy-propoxy) benzophenone (HMB). The influence of grafting yield and the other grafting conditions upon photostabilization efficiency of LDPE films were then studied. The chemically bound monomer (HMB) was localized mainly near the surface of an LDPE film. The grafted LDPE film was exposed to an ultraviolet radiation source, and the degree of oxidation and other photooxidative changes were determined by transmission IR and ATR IR spectroscopy. Experimental results show that radiation grafting of a UV-stabilizer upon LDPE films is an efficient photostabilization method. 相似文献
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EPDM与EA接枝共聚反应 总被引:2,自引:0,他引:2
以BPO为引发剂,二甲苯为溶剂,在EPDM上接枝丙烯酸乙酯(EA)红外光谱分析与溶解实验证明了接枝物的存在;接触角实验证明,接枝后EPDM的极性加大;皂化水解接枝物后,用化学滴定法测定了接枝物的接枝率。讨论了单体浓度、引发剂浓度及反应温度对接枝率的影响,也研究了氧对此反应体系的影响,并计算了此接枝反应体系的接枝反应活化能。 相似文献
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To prepare super water absorbent hydrogels of wood cellulose fibers, poly (methyl acrylate) (PMA) was copolymerized onto softwood sulfite pulp fibers using free radical initiator followed by alkaline hydrolysis. Ceric ammonium nitrate (CAN) was used as the free radical initiator. Effects of various parameters such as fiber concentration, monomer/pulp (M/pulp) ratio, CAN concentration, and reaction time on the grafting yield and on other grafting parameters were investigated. The graft conversion was the same from low to medium fiber concentration. The amount of initiator required was found to be independent of fiber concentration to achieve maximum grafting yield. Different fiber fractions (classified based on their length) have no effect on the grafting yield. The evidence of graft copolymerization was determined by using ATR‐IR spectroscopy. The X‐ray diffraction (XRD) analysis shows that grafting takes place both in amorphous and crystalline regions of cellulose fibers and the decrease in crystallinity of the grafted fibers with an increase in grafting yield was confirmed. The surface morphology of the PMA‐g‐cellulose was characterized by scanning electron microscopy (SEM). The water retention value of the hydrolyzed grafted pulp was determined based on a centrifugation technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
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The homogeneous grafting of a hydrophilic monomer onto cellulose derivatives was carried out in an aqueous system at 30, 50, 70, and 90°C during reaction periods of 30–180 min. The graft polymer was isolated by ethanol from the reaction mixture, dried, and weighed. The grafted polymer was characterized by the IR method, as well as the microscopic sample morphology detected by scanning electron microscopy. The water absorption capacities and grafting values of the grafted cellulose derivatives were also determined. The maximum grafting yield was obtained at 30°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2629–2638, 2002 相似文献
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A study was made to modify water‐soluble poly(vinyl alcohol) (PVA) by grafting acrylic acid and styrene (AAc/Sty) comonomers using gamma rays as an initiator. The factors that affect the preparation process and grafting yield were studied and more economical grafts under the most favorable reaction conditions were obtained. It was found that the high degree of grafting in such systems was obtained in the presence of an ethanol–water mixture in which water plays a significant role in enhancing the graft copolymerization. The critical amount of water to afford the maximum grafting yield was evaluated. The effect of the comonomer composition on the grafting yield was also investigated and it was observed that using a mixture of AAc/Sty monomers influences the extent of grafting of each monomer onto the PVA substrate and the phenomenon of synergism occurs during such a reaction. Also, the degree of grafting increases as the content of the solvent decreases in the reaction medium. However, the grafting yield increased as the total dose increased. The graft copolymer was characterized by IR and UV spectroscopic methods. The permeation of heavy metals such as Ni and Co through the grafted membranes was investigated and the efficiency of the separation process was also determined. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 806–815, 1999 相似文献
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Radiation induced graft copolymerization of vinyl monomers and their binary mixture onto rayon fibre
Ethyl acrylate (EA), Vinyl imidazole (VI), and their binary mixture have been copolymerized onto rayon in aqueous medium by mutual method using γ-radiation. The graft yield has been determined as a function of different reaction parameters such as total dose, concentration of vinyl monomers, and amount of water. Effect of surfactant (1-octane sulfonic acid, sodium salt) has been studied on the percentage of grafting of EA, VI, and (EA + VI). A plausible mechanism has been suggested to explain the observed behavior of the surfactant on grafting. Water retention and moisture regain of the grafted film was determined at appropriate relative humidity. The graft copolymers have been characterized by IR spectroscopy and scanning electron microscopic methods. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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LLDPE与MAH熔融接枝反应的研究 总被引:5,自引:0,他引:5
考察了影响LLDPE与MAH熔融接枝反应的因素,用红外光谱法表征了接枝物的存在,用元素分析法和红外光谱法联立得到了测接枝率的半经验公式。 相似文献
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Carboxylic acid group was introduced by radiation-induced grafting of acrylic acid (AAc) onto a polypropylene (PP) nonwoven
fabric for a battery separator. The AAc-grafted PP nonwoven fabric was characterized by IR, SEM, and TGA. The wetting speed,
electrolyte retention, electrical resistance, and tensile strength were evaluated after grafting of AAc. It was found that
the wetting speed, electrolyte retention, thickness, and ion-exchange capacity increased, whereas the electrical resistance
decreased with increasing grafting yield. The elongation of AAc-grafted PP nonwoven fabric decreased with increasing grafting
yield in dry state, whereas the elongation increased in wetting state. 相似文献