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通过采用1,1-二苯基乙烯作为降活剂降低苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)活性大分子的活性,然后用2-乙烯基吡啶进行封端聚合,合成了苯乙烯-丁二烯-苯乙烯-2-乙烯基吡啶多嵌段共聚物,研究了降活剂和单体用量及反应条件对聚合的影响。结果表明,在降活剂用量控制为活性中心的1.0倍(摩尔比)、2-乙烯基吡啶质量分数控制为活性SBS的3%以下、反应温度在60~83℃及反应时间不少于35min时能够制得相对分子质量可控且分布较窄的嵌段共聚物。 相似文献
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以2,4-二氯-5-氟苯乙酮为起始原料,通过β-酮酸酯化,与原甲酸三乙酯缩合,同2-氨基吡啶发生取代,再经环合反应、硼配合反应和哌嗪化反应合成得到了N-吡啶取代喹诺酮抗菌化合物,总收率为39.3%,并对其抗菌活性进行了试验。 相似文献
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采用Re2O7负载ZSM-5沸石分子筛作为催化剂,以固定床为反应器,催化2-甲基吡啶合成2-乙烯基吡啶.系统地考查不同硅铝质量比的ZSM-5分子筛催化剂、反应温度、反应时间以及物料配比对2-乙烯基吡啶收率的影响,筛选出合适的反应条件.反应的最优条件为选取硅铝比为25的ZSM-5分子筛负载Re2O7,2-甲基吡啶∶甲醛为1∶4,反应温度为335℃,此时2-乙烯基吡啶的收率可达89.7%.该工艺操作简单,安全性高,条件温和,不易腐蚀管道,反应时间短,收率高,适合工业化生产. 相似文献
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采用化学还原法,以硝酸银(AgNO3)、过氧化氢(H2O2)和聚乙烯吡咯烷酮(PVP)等为原料制备了纳米银粉无机抗菌剂,然后将其加入到聚丙烯酸酯粘合剂体系中制备纳米银粉抗菌整理液,并通过抑菌圈法对其抗菌性能进行了评价。实验结果表明,纳米银粉抗菌剂较佳的反应条件为w(AgNO3溶液)=5%,活化时间为12h,w(H2O2溶液)=6%,w(PVP溶液)=5%,反应温度为40℃,反应时间为3h;当抗菌整理液中银粉浓度为0.5g/L时,对金黄色葡萄球菌的抑菌圈直径为13.1mm,对大肠杆菌的抑菌圈直径为13.7mm。将抗菌试验后的试样放置6个月后,抑菌环仍然清晰未受细菌感染;该纳米银粉无机抗菌剂具有优良的抗菌性能和抗菌持久性。 相似文献
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A novel antibacterial material with surface immobilized polyvinylpyrrolidone‐iodine complex was synthesized facilely by a two‐step approach. First, N‐vinylpyrrolidone (NVP) was photografted onto polymeric substrates, and subsequently the surface‐grafted polyvinylpyrrolidone (PVP) underwent complexation of iodine. In the UV‐induced photografting process, PVP was efficiently grafted onto the polypropylene (PP) film surface by a unique film interlayer photopolymerization (FIP) technique; the grafting yield (Yg) could be controlled by varying the irradiation time or the monomer concentration. Further, we demonstrated that the grafted PVP chains could readily perform the complexation reaction with iodine as the homopolymer PVP does, which was characterized by UV–vis spectroscopy. The antibacterial activity of the modified polymer against Escherichia coli, Staphylococcus aureus, and Candida albicans was investigated. The results show that the modified PP film with surface‐immobilized PVP‐I complex has a desirable antibacterial property, with broad spectrum and high efficiency. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2026–2031, 2005 相似文献
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将无毒、抗菌谱广、抗菌效率高、热稳定性好的载银无机抗菌剂与PE熔融挤出制备了打孔膜用抗菌母粒,研究了抗菌母粒的添加对打孔膜的抗菌性能、光老化性能、安全卫生性能的影响。研究结果表明:抗菌母粒属实际无毒级物质;随着抗菌母粒的增加,抗菌打孔膜的抗菌性能增加;当抗菌母粒的添加量为4.0%时,即抗菌剂在打孔膜中的质量百分含量为1.0%时,抗菌打孔膜的性价比最佳。 相似文献
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以麦饭石为载体、Ag+和Zn2+为抗菌离子,通过液相离子交换反应,制备载银锌的麦饭石无机抗菌剂。采用抑菌率对所得产物的抗菌性进行检测,采用XRD、SEM对产物的结构与形貌进行表征,并采用缓释法对产物的耐久性进行研究。实验结果表明:在反应时间为4 h,反应温度为60℃,Ag+和Zn2+浓度分别为0.1、2 mol·L-1,pH值为8的条件下,制备的麦饭石抗菌剂具有优异抗菌性和耐久性。抗菌机理初步分析为通过离子交换或吸附进入麦饭石结构内的Ag+和Zn2+能从载体中持久缓慢地释放出来,与细菌细胞作用,杀灭细菌,从而保持该抗菌剂良好的抗菌能力。 相似文献
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Polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) hydrogel has been prepared by using γ-irradiation technique. In the present
study the conclusion on miscibility of PVA/PVP blends, confirmed qualitatively and quantitatively by using Fourier transform
infrared spectroscopy and differential scanning calorimetry, respectively. PVA and PVP are found to form a thermodynamically
miscible pair. The physical properties such as gel fraction and water absorption performance of the prepared hydrogels were
measured, it was found that the gel fraction increases with increasing irradiation dose while the swelling of PVA/PVP blended
hydrogels nearly tends to increase with increasing PVP content and reduced with enhanced irradiation doses. The hydrogel pore
structure of various PVA/PVP compositions were tested with SEM. Ability of PVA/PVP hydrogels to absorb and release antimicrobial
compounds was tested using amoxicillin as an antibacterial and ketoconazole as an antifungal. Antimicrobial activity of PVA/PVP
hydrogels was examined using four bacteria, and four fungi. No antibacterial or antifungal activities of non-loaded PVA/PVP
of various compositions were detected while the loading ones found to have antimicrobial activity. Results showed resistance
of Pseudomonas aeruginosa and Candida albicans to PVA/PVP, while Bacillus subtilis was very sensitive. Biodegradation of PVA/PVP hydrogels was investigated by burial method in two types of local soils (clay
and sandy soils). The highest degradation rate was found to be achieved using clay soil. Also, effect of irradiation dose
on its biodegradability was tested. The results showed that the radiation prepared PVA/PVP hydrogels can be use as biomaterials. 相似文献