大豆蛋白质改性腈纶的接枝工艺探讨

采用大豆蛋白质接枝改性腈纶,研究了接枝工艺条件对接枝率的影响。结果表明:在加入过量的蛋白质,加入质量分数10％的NaOH用量为1 mL、反应温度80℃,反应时间5 min,能够获得较好的接枝效果,腈纶表面蛋白质接枝率达3．2％。红外分析表明在腈纶表面接枝蛋白质效果明显。     

蛋白质接枝改性腈纶的水解工艺研究

采用NaOH溶液对腈纶进行水解,表面接枝蛋白质制得改性腈纶。讨论了NaOH浓度、水解温度、水解时间对腈纶接枝效果的影响。结果表明:在水解反应温度80~90℃、NaOH溶液质量分数14%、水解时间15 m in时,改性腈纶接枝率较高。力学性能分析和电镜表面观察表明:在腈纶表面接枝大豆蛋白质,不仅可以赋予纤维表面完整的蛋白质覆盖层,而且还可以较好的弥补纤维因水解而产生的表面损伤和力学性能下降等缺陷。     

腈纶接枝蛋白质水解条件对吸水率和接枝率的影响

研究了腈纶表面接枝蛋白质水解工艺条件对吸水率和接枝率的影响关系。通过红外光谱分析结果证实了腈纶纤维已接枝上大豆蛋白。实验结果还表明,水解时间、水解温度及NaOH浓度都对腈纶纤维的吸水率和接枝率有很大的影响。在一定的水解强度范围内,腈纶的吸水率及接枝率均随水解强度的增加而不断提高;当水解强度过高时,接枝率反而会下降。腈纶表面接枝蛋白质的最佳水解工艺条件为:水解时间15 min、水解温度为90℃、NaOH浓度为10%。X-射线衍射分析表明,腈纶经过水解、接枝后,纤维的聚集态结构没有明显变化。     

微乳液法腈纶接枝聚苯胺及其性能研究

采用低温等离子体技术对腈纶纤维表面进行处理,使用苯胺微乳液在腈纶表面进行接枝聚合,对腈纶进行改性处理,通过增重率、导电率测试、接枝聚合的因素和接枝聚合对腈纶纤维结构、导电性能和强力进行分析评价;扫描电镜和红外测试显示聚苯胺成功接枝上腈纶表面;腈纶接枝聚苯胺后,导电性能增加,强力变化不大,但伸长率略有降低。     

接枝改性腈纶织物亲水性能的研究

利用等离子体辐照引发聚丙烯腈纤维大分子,进行反相微乳液接枝聚合,在腈纶织物上接枝季胺盐类单体(F单体),以改善腈纶织物的亲水性能,借助红外光谱和扫描电镜对改性腈纶进行表征,探讨了改性腈纶织物的吸水性、回潮率、透气性及力学性能与其接枝率的关系。结果表明:F单体已接枝到腈纶织物上,接枝率和回潮率呈线性关系;当接枝率为20%左右时,回潮率达到约7%;当接枝率小于20%时,对腈纶织物透气性影响较小;随着接枝率的增加,腈纶织物的抗弯刚度减小,断裂强力和伸长有所增加。     

混合短链PEG硫醇自组装膜制备与蛋白质固定

采用自组装技术制备了一系列在金表面不同摩尔比的PEG硫醇混合自组装膜,并将蛋白质共价固定在膜表面。通过AFM、接触角测试仪和XPS技术对混合自组装膜和蛋白质接枝反应后表面的物理和化学性质进行了分析表征。通过抗原-抗体反应实验检验了蛋白质膜表面生物活性的相对大小。结果表明:自组装膜表面的比例组成与溶液中的组成并不完全一致。接枝后蛋白质的形貌及蛋白质膜表面粘附力分布与自组装膜的表面组分有关并会影响其与抗体的反应活性。当反应溶液中SH-PEG-OCH3/SH-PEG-COOH摩尔比为1∶6时,所形成的自组装膜的表面羧基含量最大,同时粘附力也达到最高值,蛋白质活性也最大。     

膜色谱所用微孔膜接枝改性的初步研究

结合膜色谱分离蛋白质的应用背景,采用钴源辐射接枝法和紫外辐射接枝法对聚乙烯膜进行了膜孔表面接枝改性的初步研究与探讨。     

对腈纶废丝碱法水解产物接枝后絮凝性能的研究

腈纶废丝在常压碱性条件下水解后,与二甲胺进行接枝制备絮凝剂的适宜条件为:NaOH、水、二甲胺用量分别为14 g、160 mL、36 g,接枝温度为90℃,在此条件下制得的絮凝剂对废水的除浊效果可达到92%以上。     

蚕丝蛋白改性腈纶的研制(英文)

先用丙烯腈对蚕丝蛋白进行接枝改性 ,然后将其与常规腈纶纺丝原液共混纺丝 ,制备了蚕丝蛋白改性腈纶。结果表明 :随着蛋白含量的增加 ,蚕丝蛋白改性腈纶的断裂强度会逐渐下降 ,断裂伸长则变化不大 ,当纤维中蚕丝蛋白的含量小于 15 %时 ,其机械性能基本上能满足后纺加工的要求 ;随着蛋白含量的增加和改性比的增大 ,蚕丝蛋白改性腈纶的保水率增加 ;改性比的变化对蚕丝蛋白改性腈纶的机械性能基本没有影响 ;蚕丝蛋白改性腈纶织物的导湿性能较常规腈纶织物有显著提高     

载体材料表面化学组成对蛋白质吸附行为的影响研究进展

蛋白质在载体表面的吸附行为,如其吸附速率、吸附量以及取向和构象的变化,在很大程度上依赖于载体材料的表面化学组成。调控载体材料的表面化学组成已成为控制蛋白质吸附行为的重要手段。本文主要对载体材料表面不同组成对蛋白质吸附行为的影响进行了归纳。介绍了材料表面的功能基团包括疏水基团（甲基和含氟基团）和亲水基团（羟基、氨基和羧基）对蛋白质吸附行为的影响。另外,在载体材料表面接枝聚合物链是一种常用的有效调控表面化学组成的方法。重点介绍了材料表面接枝不同聚合物链时,聚合物链的种类、长度、密度和链的结构对蛋白质吸附行为的影响。     

Surface modification of polyacrylonitrile (PAN) fibers by grafting of natural polymer-soybean protein (SP)

Summary A novel method of modifying polyacrylonitrile (PAN) fibers by grafting of soybean protein (SP) onto it was studied. The reactant of PAN-g-SP fiber was prepared based on chlorination of the hydrolyzed PAN fiber. The effects of chlorination and grafting conditions on the grafting efficiency were investigated. The grafting efficiency first increases with the increase of the addition of thionyl chloride (SOCl₂), chlorination time and temperature and then levels off. In grafting reaction, grafting efficiency increases at first and then declines significantly with increasing addition of sodium hydroxide (NaOH), grafting temperature and time. The grafted polymer was characterized by FT-IR spectroscopy, X-ray diffraction and SEM images. The results indicated that SP was grafted onto the PAN fiber. PAN-g-SP also exhibits good hygroscopicty and proper mechanical properties.     

PAN ultrafiltration membranes grafted with natural amino acids for improving antifouling property

In this report, antifouling polyacrylonitrile (PAN) ultrafiltration membranes were prepared from blends of PAN/polyglycidyl methacrylate (PGMA) via phase inversion method followed by the grafting of natural amino acids through epoxy ring-opening reaction. The grafted PAN membranes possessed highly stable hydrophilic surfaces as a result of the grafting of amino acids, which was adequately demonstrated in attenuated total reflectance–Fourier transform infrared spectroscopy (ATR/FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The results of tensile strength and scanning electron microscopy (SEM) images further proved that the surface modification had little effect on their mechanical properties, surface, and cross-sectional morphologies. Meanwhile, remarkable resistance against bovine serum albumin (BSA) and lysozyme (Lyz) fouling was observed for the neutral amino acid-based PAN membranes due to the formation of zwitterionic hydration layer on the membrane surface, while PAN membranes grafted with charged amino acids were able to prohibit the approach of like charged proteins with reduced deposition and provide the driving force for oppositely charged protein adsorption. Furthermore, the ultrafiltration and antifouling performance of PAN membranes were investigated by BSA filtration experiments. Compared with the pristine PAN membrane, all the modified PAN membranes exhibited higher pure water flux, better flux recovery ratio, lower rejection, less total permeation resistance, and preferable stability, having potential applications in protein separation and purification.     

Radiation synthesis of polypropylene-acrylate grafted fiber and its remediation in the spillage of water-insoluble organic chemicals

A new kind of functionalized polypropylene(PP)-acrylate grafted fiber were prepared by radiation-induced graft polymerization of methyl acrylate (MA), ethyl acrylate(EA) and butyl acrylate (BA) monomer onto the PP fiber matrix, as a recovery adsorbent for insoluble organic chemicals. The grafting conditions of monomer concentration and irradiation time on the grafting degree were optimized. The obtained grafted fiber sample was identified by Fourier transform infrared (FT-IR) spectrometer and scanning electron microscopy (SEM) to characterize the chemical and morphological changes of the polypropylene fiber surface. The adsorption results indicated that the grafted fiber could be used to remove organic chemicals from water surface. The adsorption capacity of grafted fiber with different acrylate monomer was obviously different for the same chemicals, therefore, investigations with respect to organic removal, dynamic oil retention, and reusability, the effect of monomer polarity on the adsorption capacity of grafted fiber was especially highlighted in this study.     

聚丙烯腈纤维吸湿改性方法及研究现状

综述了国内外吸湿性聚丙烯腈(PAN)纤维的研究现状;阐述了PAN纤维的吸湿机理及影响吸湿性的因素;详细介绍了改善PAN纤维的吸湿性的化学方法和物理方法;PAN纤维吸湿改性化学方法有通过聚合和共聚引进亲水基团、与亲水物质接枝共聚、对纤维表面进行碱减量处理、纤维表面的亲水整理、等离子体处理等;PAN纤维吸湿改性物理方法有与...     

Grafting of cellophane films using magnetron-enhanced plasma polymerization

The cellophane films were grafted with PAN for various time durations in magnetron enhanced air plasma. A magnetron-coupled plasma system was developed for the purpose. The rates of polymer deposition and etching were studied. The changes occurring in the angle of contact of water were studied. The attenuated total reflection—infrared spectroscopic studies confirmed the grafting of cellophane surface by polyacrylonitrile (PAN). The water vapor transmission rates through the grafted samples were also studied.     

PAN接枝CNTs的制备及其复合溶液的流变行为

采用浓硝酸、氯化亚砜、三乙烯四胺先后对碳纳米管(CNTs)进行氧化、酰氯化和胺化,通过原位聚合将聚丙烯腈(PAN)接枝到CNTs端头或表面制得改性CNTs;研究了含改性CNTs的PAN复合溶液的流变行为。结果表明:PAN接枝到CNTs上并形成网络结构,被接枝的聚合物的质量分数约59%,接枝率约为144%。通过原位聚合,改性CNTs可均匀分散到PAN/二甲基亚砜溶液中,复合溶液体系存在网络结构,流变行为稳定,具备可纺性。     

Grafting of polyacrylonitrile onto guar gum under microwave irradiation

Using microwave (MW) irradiation grafting of polyacrylonitrile (PAN) onto guar gum in water was done without using any radical initiator or catalyst within a very short reaction time. The extent of grafting could be adjusted by controlling the reaction conditions and maximum percentage grafting (%G) of about 188% was obtained under optimum conditions in 1.66 min. The average molecular weight of the grafted PAN chains and water‐retention power of the alkali hydrolyzed MW‐grafted gums were also determined and compared with those of the conventionally synthesized (cs) graft copolymer. A representative MW‐grafted copolymer, guar‐g‐polyacrylonitrile was characterized by IR, NMR, XRD, TGA, and elemental analysis. A plausible mechanism for the grafting under MW was proposed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1569–1575, 2004     

Surface modification of acrylonitrile copolymer membranes by grafting acrylamide. I. Initiation by ceric ions

Surface modification of membranes of an acrylonitrile copolymer (PAN) containing 5.5% methyl methacrylate (MMA) and 4.0% sodium methylpropylenesulfonate by grafting acrylamide (AAm) with cetric ammonium nitrate as initiator in the aqueous medium has been studied. Results showed that the extent of grafting was varied with some parameters, such as dimethyl formamide and Tween-20 amount in the reaction solution, concentration of AAm, and reaction time. The grafted copolymer was verified by infrared spectra and X-ray photoelectron spectroscopy. Both of these methods also showed that the ester group of MMA unit on the surface of PAN membranes may be partially hydrolyzed into carboxyl group in the copolymerization condition. Surface and pore structures of PAN membranes after grafting were viewed under a scanning electron microscope (SEM). From SEM photos we know that AAm homopolymer branches were grafted onto the surface of the membrane and the morphology of membrane did not change. Results of contact angle of isooctane on the membrane under water showed that the wettability of the modified membrane was improved. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1521–1529, 1997