共查询到20条相似文献,搜索用时 91 毫秒
1.
烯类单体与聚酰胺(尼龙)纤维接枝共聚合已有报道.Varma等人研究了Ce4+引发丙烯腈、丙烯酰胺分别与尼龙纤维的接枝共聚反应。Lenka发表了用P2O48-引发甲基丙烯酸甲酯(MMA)与尼龙6纤维接枝共聚合的研究结果.Nayak等人报道了用乙酰丙酮锰为引发剂使MMA与尼龙6接枝共聚合.本文以二甲基苯胺(DMA)/硫酸铜为引发体系,用MMA接枝尼龙66纤维丝,研究了Cu2+浓度等因素对该接枝共聚反应的影响. 相似文献
2.
3.
4.
5.
聚丙烯微孔膜表面的等离子体接枝 总被引:2,自引:1,他引:2
通过氢气氛等离子体处理,在聚丙烯微孔膜表面接枝了聚丙烯酸,改善了膜表面的亲水性。接枝率与等离子体放电功率、放电时间和溶液浓度有关,微孔膜内外表面及不同位置接枝效率有差别。接枝后微也膜的表面孔径减少了。 相似文献
6.
以过氧化苯甲酰(BPO)作引发剂,通过溶液接枝聚合法把苯乙烯接枝到碱处理过的聚偏氟乙烯(PVDF)膜上,磺化后得到聚偏氟乙烯接枝苯乙烯磺酸(PVDF-g-PSSA)电解质膜。研究发现碱处理过的PVDF膜更容易与苯乙烯发生接枝聚合反应,且接枝率与碱处理时间呈线性变化关系。用红外光谱、差示扫描量热法检测PVDF膜经过接枝以及随后的磺化所发生的膜结构变化,并用SEM观察PVDF膜接枝前后以及接枝磺化后产物PVDF-g-PSSA膜的形貌及硫分布。研究表明,用KOH碱处理过的PVDF膜与苯乙烯进行接枝共聚反应时,PVDF膜结构在接枝前后和磺化前后发生变化,说明苯乙烯确实接枝到PVDF膜上。 相似文献
7.
8.
9.
对Kevlar纤维进行了改性,使其成为己内酰胺阴离子开环聚合的活性中心,采用阴离子接枝法在Kevlar纤维(KF)表面接枝尼龙6低聚物,并与基体尼龙6混合,用挤出和注塑方式制备了尼龙6/改性Kevlar纤维(PA6/KF1)复合材料。ESEM和XPS分析表明,Kevlar纤维表面接枝上了尼龙6低聚物。比较了尼龙6/未改性Kevlar纤维(PA6/KF0)和PA6/KF1复合材料的力学性能及破坏形态,同时探讨了其破坏机理。结果表明,接枝尼龙6的KF1增强了KF与尼龙6复合材料界面的相互作用,拉伸强度、弯曲强度和弯曲模量分别提高了20.69%、12.26%和14.23%,但冲击强度降低了8.2%;当复合材料被破坏时,未改性纤维表面只粘附有少量的树脂尼龙6,而改性纤维的表面有较多的树脂包覆层,呈部分非界面脱粘破坏,具有良好的界面结合能力。 相似文献
10.
11.
采用常温下γ射线预辐照引发接枝的方法,在聚全氟乙丙烯(FEP)上接枝了丙烯酸(AA)和对苯乙烯磺酸钠(SSS),制备了一种含羧酸基团和磺酸基团的接枝膜.傅立叶变换红外光谱(FT-IR)分析证明了磺酸基团和羧酸基团的成功引入.采用XRD、TGA和接触角研究了接枝率对FEP膜的结晶度、热学特性及亲水性等性能的影响.结果表明,随着制备的FEP膜接枝率的增加,膜的结晶度、热稳定性和接触角逐渐减小;与此相反,FEP膜的亲水性能随接枝率的增加而增加.接枝膜湿敏性能测定结果表明,在相对湿度从5%RH变化到98%RH时,接枝膜电阻线性变化范围接近3个数量级,具有响应速度快(吸附<1min,解吸<2min),湿滞小(<3%RH)的特点,具有应用于电阻型湿度传感器的广阔前景. 相似文献
12.
Jianhua Zu Jianqiu Zhang Guisheng Sun Ruimin Zhou Zhaomin Liu 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):185-192
Electron beam radiation induced grafting of acrylic acid (AA) and sodium styrene sulfonate (SSS) onto high-density polyethylene
(HDPE) membranes was investigated by the pre-irradiation method, and a cation-exchange membrane containing bifunctional groups
was synthesized. The effects of grafting conditions such as monomer concentration, radiation dose and temperature on grafting
yield were studied. The dependence of grafting yield on pre-irradiation dose and monomer concentration was found to be 0.54
and 2.21, respectively. The activation energy for the grafting was calculated to be 22.2 kJ/mol. Infrared spectroscopy analysis
of the grafted membrane confirmed the existence of sulfonate and carboxylic acid groups. 相似文献
13.
Jianhua Zu Zhiqiang Hu Weitao Wang Jianqiu Zhang E. S. Pino Jianzhong Gu Long Tong 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):479-484
A kind of ion-exchange membrane with strong acid and weak acid groups was prepared by radiation-induced grafting of acrylic
acid (AA) and sodium styrene sulfonate (SSS) onto high-density polyethylene membrane (HDPE). The effect of additives such
as sodium acetate, sodium chloride on grafting yield was studied. It was found that for either pre-irradiation method or simultaneous
radiation method, the weak acid salt of strong alkali sodium acetate had a complex effect on the grafting yield by “pH effect”
and “ion pair effect”, and the neutral salt sodium chloride was helpful to the increase of grafting yield by “ion pair effect”. 相似文献
14.
Wei Junfu Zhao Kongyin Wang Lei Zhang Huan Chen Li Zhang Zhengpu 《Macromolecular Symposia》2010,297(1):231-239
Summary: A modified poly (vinylidene fluoride) (PVDF) hollow fiber membrane with higher flux and flux recovery rate was prepared by γ-radiation induced grafting of acrylic acid (AA). The influence of radiation dose and monomer concentration on the grafting degree was investigated. The results indicated that the grafting degree increased in the lower monomer volume fraction until the monomer volume fraction exceeded 20%. The grafting degree increased with the increase of radiation dose. Structural and morphological of the original and grafted membrane surface were characterized by FT-IR, scanning electron microscopy (SEM). The results indicated that acrylic acid was grafted onto PVDF hollow fiber membrane and the grafted membrane was more hydrophilic than original PVDF. There was a slight increase of breaking strength and yield stress with the increase of the grafting degree of AA. The pure water flux increased initially but decreased subsequently with the raise of grafting degree. When the grafting degree was 4.4%, the maximum pure water flux reached 1496.3 L/m2 × h, 1.79 times of original membrane. The pure water flux, flux recovery rate and rejection ratio for bovine serum albumin could improve simultaneously in a low grafting degree (<4.4%). 相似文献
15.
聚乙烯基咪唑/陶瓷复合膜的渗透汽化性能 总被引:2,自引:0,他引:2
通过自由基接枝聚合反应在硅烷化处理的沉积有SiO2活性层的无机陶瓷微孔膜上接枝乙烯基咪唑(VI),经质子化后,制备出一种聚电解质亲水性有机-无机复合膜。用FT-IR表征了接枝PVI前后化学组成的变化;用TGA 测定了单体在二氧化硅粉末上的接枝率;用SEM观察了接枝反应前后膜表面形态的变化;系统研究了操作条件对膜的渗透汽化分离性能的影响。结果表明,这种膜用于醇/水、酸/水等水溶液的分离有很好的选择性和渗透性,膜的渗透性随操作温度的变化表现异常,结合SEM的结果可以推断有机单体主要是在无机膜的孔内接枝形成活性分离层。 相似文献
16.
17.
Yanying Wang Li Zhang Shibo Gao Mei Gong Di Huang Xiaoyan Wang Yubao Li 《Polymer Science Series B》2013,55(11-12):566-572
Surface modification of ethylene-vinyl acetate membrane by grafting poly(N-isopropylacrylamide) was initiated under UV-irradiation. Besides benzophenone and ammonium persulfate were used as initiators, which could enhance the yield of grafting markedly. The occurrence of grafting polymerization of N-isopropylacrylamide was testified by the attenuated total multiple reflection technique and X-ray photoelectron spectroscopy. Scanning electron micrograph showed that the surface morphology of ethylene-vinyl acetate membrane changed after modification. The lower critical solution temperature of the membrane was determined by differential scanning calorimetry. The wettability of membrane was investigated by water contact angle measurement. The results showed that the grafting degree increased with irradiation time, monomer and ammonium persulfate concentration at the beginning of reaction. It was also found that the modified membrane surface became hydrophilic and displayed thermosensitivity similar to that of poly(N-isopropylacrylamide) gel, and the lower critical solution temperature was about 32°C. 相似文献
18.
聚乙烯-葡萄糖氧化酶膜的制备和性能研究朱如瑾,殷弘浩,刘永盛,黄家湛(成都高分子材料国家重点实验室成都科技大学高分子研究所成都610065)关键词聚乙烯,等离子体,固定化酶,葡萄糖氧化酶固定化酶是60年代发展起来的生物工程技术I‘].酶的固定化方法主... 相似文献
19.
20.
《Radiation Physics and Chemistry》2007,76(4):707-713
N-isopropylacrylamide (NIPAAm) monomer was grafted on and in poly(vinylidene fluoride) (PVDF) micro-pore membrane by γ-irradiation. The influence of irradiation and reaction conditions on the grafting yield was investigated in detail. The chemical structure of NIPAAm-grafted PVDF (NIPAAm-g-PVDF) membrane was characterized by Fourier transform infrared spectra and X-ray photoelectron spectra measurements. The morphology of the sample surface as well as the cross-section before and after grafting was characterized by scanning electron microscope. The temperature sensitive properties of the membrane were monitored by measuring the conductance as well as the water flux through the sample thickness. The results show that the membrane exhibits clearly temperature-sensitive permeability to water as expected, i.e. the permeability of water changes dramatically as the temperature goes over the lower critical solution temperature of NIPAAm. 相似文献