预辐照聚丙烯无纺布共接枝丙烯腈和丙烯酸的研究

研究了在空气条件下丙烯腈和丙烯酸在预辐照聚丙烯无纺布上的共接枝反应,以及预辐照吸收剂量、接枝反应温度、反应时间、单体浓度及比例和摩尔盐浓度对接枝率的影响。结果表明,接枝的最佳条件为：反应温度75℃,反应时间4h,单体浓度50％。并对接枝前后的聚合物进行了红外光谱分析。     

聚丙烯胺肟螯合纤维的辐射合成及其对Pb(Ⅱ)离子的吸附性能

采用预辐照接枝法,在空气或氮气气氛下利用电子束对聚丙烯纤维进行辐照。然后,将样品置于4种不同溶剂(水、甲醇、正丁醇、10％甲醇水溶液)的丙烯腈溶液体系中进行接枝反应,并通过与盐酸羟胺溶液反应,引入胺肟基团,获得一种机械性能较好的偕胺肟螯合纤维(PPAO)。最后浸于硝酸铅标准溶液中,测定其对铅的吸附量。结果表明,接枝率与预辐照气氛、反应温度、反应液体积、单体浓度都有密切关系。聚丙烯纤维在水溶液和10％甲醇水溶液中接枝率较高。当纤维在空气中预辐照,丙烯腈单体体积浓度为30％,温度为70℃时,聚丙烯纤维的接枝率最高;对Pb(Ⅱ)的吸附容量为0．362mg／g(纤维)。     

60Coγ射线预辐照制备淀粉-丙烯酰胺接枝物

采用预辐照的方法研究了淀粉与丙烯酰胺的接枝反应,制备出了淀粉与丙烯酰胺的接枝物;采用元素分析法测量了接枝率.对预辐照接枝反应的一些影响因素,如吸收剂量、反应温度、反应时间、阻聚剂及辐照后效应也进行了研究,并获得了相关结果.淀粉预辐照的吸收剂量约10kGy,辐照后10min内在2530C下进行接枝可以获得80%以上的接枝率.     

聚苯乙烯-二乙烯基苯胺肟螯合树脂的辐射接枝合成

以聚苯乙烯-二乙烯基苯（SDB）树脂颗粒为基体，通过预辐照接枝聚合途径在空气气氛中接枝丙烯腈(AN)，然后用盐酸羟胺作功能化处理而引入胺肟基团。采用傅里叶红外光谱仪和扫描电镜等对产物的化学结构及表面微观形貌进行分析。分析结果表明：只有在高吸收剂量（0.6～2.4MGy）条件下才能发生接枝反应，且接枝率随吸收剂量增加而提高。在选定的吸收剂量（2.4MGy）条件下，以丙烯腈单体与水体积比1∶7，于80℃下反应4h所得的接枝产物（SDBAN）再与盐酸羟胺溶液反应，在中性条件下获得了性能良好的偕胺肟基螯合树脂(SDBAO)产物。     

^60Coγ射线预辐照制备淀粉—丙烯酰烷接枝物

采用预辐照的方法研究了淀粉与丙烯酰胺的接枝反应,制备出了淀粉与丙烯酰胺的接枝物;采用元素分析法测量了接枝率。对预辐照接枝反应的一些影响因素,如吸收剂量、反应温度、反应时间、阻聚剂及辐照后效应也进行了研究,并获得了相关结果。淀粉预辐照的吸收剂量约１０ｋＧｙ,辐照后１０ｍｉｎ内在２５～３０℃下进行接枝可以获得８０％以上的接枝率。     

聚丙烯与丙烯酸的辐射接枝反应的研究Ⅱ——预辐照聚丙烯的接枝共聚反应

本工作采用~(60)Coγ射线预辐照方法,研究聚丙烯毡在丙烯酸水溶液中的接枝共聚反应动力学。探讨了预辐照剂量,辐照气氛,接枝反应温度以及单体浓度对接枝共聚反应的影响。实验结果表明接枝反应速率与预辐照剂量的关系为0.445次方。由此得知反应是按自由基机理进行的。此外,计算了本体系的表观活化能为25.52kcal/mol。由本试验获得的接枝共聚物,其亲水性、透气性、及染色性均有明显地改善。但预辐照剂量超过1×10~6rad机械强度有所下降。     

预辐射引发气相接枝法制备PE-g-PAN材料

氰基是一类化学活性较高的基团,可以制备各种配位基团。接枝聚丙烯腈是引入氰基的主要方法之一。本文利用γ射线预辐射气相接枝的方法将丙烯腈接枝聚合到聚乙烯(PE)无纺布上,系统地研究了接枝率在不同温度、时间和吸收剂量时的变化规律。通过傅里叶变换红外光谱仪(Fourier transform infrared spectroscopy,FTIR)、拉力、扫描电子显微镜(Scanning electron microscope,SEM)、接触角等表征了样品的理化性能。结果证明,通过预辐射气相接枝方法可以成功的将丙烯腈接枝聚合到聚乙烯无纺布上;接枝聚丙烯腈后,无纺布的接触角会略有提高;无纺布受辐照后,机械性能下降,而接枝聚丙烯腈对无纺布的机械性能影响较小。     

高分子催化剂的研究——无机物辐射接枝丙烯腈-钯的络合物

本文采用预辐照接枝工艺研究了在无机物(氧化镁、Y型分子筛、二氧化硅等)上接枝丙烯腈,并以此为配位体的钯络合物高分子催化剂。X线光电子能谱(XPS)的研究结果表明,MgO-g-PAN-Pd(辐射接枝法)的C_(12)和O_(1?)窄谱比Mg—PAN—Pd(化学聚合法)变宽,而且多一个峰。据文献报导,该峰应归于—O—C—集团,因此MgO与丙烯腈的辐射接枝,可能是在MgO中的氧原子与丙烯腈中的β-碳原子之间进行的。用辐射接枝得到的高分子催化剂对烯烃的加氢活性和抗毒性均比用化学法担载在无机物表面上的聚丙烯腈—钯络合物催化剂要好些,而且对不同的烯烃催化加氢有一定的选择性。     

热敏智能径迹膜的研制

以N－异丙基丙烯酰胺热酶材料为单体，核径迹微孔膜为基材，用过氧化预辐照接枝技术研制出能控制开关的热敏智能径迹膜，考察了预辐照剂量，接枝温度，单体浓度和反应时间时间等因素对接枝的影响，以及膜孔开闭动态变化。亚微米级孔径上极薄的热敏接枝层，溶胀与收缩迅速，对温度开关响应更为灵魂。     

羟基磷灰石辐射接枝甲基丙烯酸甲酯反应的研究

研究了羟基磷灰石在空气中预辐照法接枝甲基丙烯酸甲酯（ＭＭＡ）反应的接枝剂量、单体浓试、接枝温度及无机酸对接枝体系的影响。结果表明，接枝率是由动力学条件控制的，经过恰当的条件选择，可以获得较高的接枝率。对接枝物进行重量法、灼烧法、扫描电镜及红外光谱研究，从不同的侧面证实ＭＭＡ已通过化学键接枝在羟基磷灰石上。表明用辐射引发无机材料接枝有机单体，改善无机－有机复合材料界面，制备生物医学材料的方法是可行的     

辐射法制备含偕胺肟和咪唑啉基团功能高分子膜的研究

本文描述了共辐照法丙烯腈在聚乙烯薄膜上的辐射接枝,该接枝体系的活化能由阿累尼乌斯公式求得为2.51 J·mol~(-1)。含偕胺肟和咪唑啉的两种功能高分子膜可以通过聚乙烯与丙烯腈的接枝共聚物分别与羟胺和乙二胺的化学反应制得。还对该两种膜在透过蒸发中的通量和分离系数作了比较。     

ACIDIC EFFECT OF RADIATION GRAFTING BETWEEN ACRYLONITRILE AND WOOL

The acidic effect in grafting of acrylonitrile onto wool fibre under mutual irradiation has been studied. The reactivity of various acids towards graft copolymerization was found as the order: H_2SO_4>HNO_3>HCl>HClO_4>HOAC.     

过氟化聚合物的苯乙烯接枝研究--辐照条件与反应条件的影响

Fuel cell is in focus as a very low exhaust new dynamo system. Especially polymer electrolyte fuel cells (PEFC) using proton exchange membranes (PEM) have attracted much attention for the electrical vehicle and other mobile applications such as cellar phone and personal computer. Conventional perfluoro-sulfonic acid membranes such as Nation() (DuPont de Nemours LTD.) have been the popular PEM used in PFEC. However, there are still several problems such as insufficient gas barrier properties, low thermal resistance, and their high costs.In this study, hawse have studied the partially fluorinated PEM for PEFC by radiation grafting onto per-fluorinated polymers such as PFA, FEP and ETFE with reactive styrene monomers using pre-irradiation grafting method in gas and in liquid phase, respectively, and successive sulfonation. Characteristic properties of the grafted and sulfonated materials have been discussed and optimized fabricating conditions were determined.Characteristic properties of the obtained materials have been measured by differential scanning calorimetry,thermogravimetric analysis and FT-IR spectroscopy, etc.In the case of irradiation in air, glass transition temperatures (Tg) of the grafted materials depend on the yields of styrene grafting onto the materials. That is higher yields of grafting give lower thermal stability. On the other hand, when the peroxy radicals were converted trapped radicals by exposure in air after irradiation under oxygen-free atmosphere, Tg of the grafted materials hardly depends on the grafting yields.Moreover, the yields of grafting in gas phase were higher than that of liquid phase. However, the sample form of grafting in gas phase has been greatly changed, whereas the sample form of grafting in liquid phase has kept its original feature.Therefore, it is suggested that the fabricating conditions for PEFC membranes were preferred to irradiation under oxygen-free atmosphere and grafting in liquid phase.Ion exchange capacities of the sulfonated-materials could be 3.0meq/g. Other properties of the obtained membranes such as chemical structure were also discussed.     

Amidoxime-based adsorbents prepared by cografting acrylic acid with acrylonitrile onto HDPE fiber for the recovery of uranium from seawater

An amidoxime-based polymeric adsorbent was prepared by pre-irradiation grafting of acrylonitrile and acrylic acid onto high-density polyethylene fibers using electron beams,followed by amidoximation.Quantitative recovery of uranium was investigated by flow-through experiment using simulated seawater and marine test in natural seawater.The maximum amount of uranium uptake was 2.51 mg/g-ads after 42 days of contact with simulated seawater and 0.13 mg/g-ads for 15 days of contact with natural seawater.A lower uranium uptake in marine test can be attributed to the short adsorption time and the contamination of marine microorganisms and iron.However,the high selectivity toward uranium against vanadium may be beneficial to harvest uranyl ion onto adsorbents and the economic feasibility for recovery of uranium from seawater.     

Effect of the displacement damage from argon ion irradiation on the synergistic effect of helium–hydrogen in tungsten

The effect of argon ion pre-irradiation on helium and hydrogen ion irradiation was investigated in tungsten. At the same time, comparative experiments were carried out on the irradiation of helium and hydrogen ions in tungsten. Without the argon ion irradiation, the energy of 35 keV hydrogen ions mainly accelerated the coalescence of defects created by the 60 keV helium ions, the irradiation damage degree increased with hydrogen ion fluence increasing. With the argon ion irradiation, lots of voids were created by argon ion irradiation, which increased the helium and hydrogen retention and the synergistic effect of helium–hydrogen in tungsten. In the same hydrogen fluence, the surface damage degree with argon ion pre-irradiation was higher than that without argon ion pre-irradiation.     

辐照接枝改性涤纶织物的亲水性能

利用电子束辐照接枝的方法将丙烯酸(Acrylic acid,AA)单体接枝到涤纶织物上来改善其亲水性。通过改变吸收剂量、接枝单体浓度、阻聚剂浓度、预辐照的吸收剂量以及前处理氢氧化钠浓度等影响因素来获得具有不同接枝率的改性涤纶织物。优化的反应条件:吸收剂量为195 k Gy、AA浓度为50%、阻聚剂(Fe SO4?7H2O)浓度为0.8%、预辐照的吸收剂量为43 k Gy、前处理Na OH浓度为15 g/L。傅里叶红外光谱证明AA已接枝成功;扫描电子显微镜分析表明改性涤纶织物的表面具有覆盖物,且随着接枝率的增大,其覆盖物明显增多;回潮率测试结果表明,改性涤纶的回潮率随接枝率的增加而逐渐增大,当接枝率达到最大值27.84%时,改性涤纶的回潮率可达3.51%。涤纶织物经30次洗涤后减重率仅1%左右,说明接枝牢度优异。     

不同分子量的丙烯酸酯对聚乙烯辐射接枝的研究

利用预辐射方法，在聚乙烯薄膜上接枝不同分子量的缩乙二醇丙烯酸酯单体。研究单体不同分子量的变化对接枝反应和接枝样品亲水性等的影响。结果表明：摩尔接枝率随单体分子量增加而非线性地降低；接枝基材的溶胀程度对分子量较大的单体的接枝反应影响较大；该片溶胀度越大，接枝率越高；单体分子量增加，接枝反应初速度下降。