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Plasma initiated polymerization is a kind of well-known radical polymerization mechanism, but it has the 'living' polymerization feature and produces ultra-high molecular weight polymer. In order to explain such phenomena, we calculate the basic data of plasma initiated polymerization of methylmethacrylate (MMA) according to the principle of polymer physics and chemistry. It results in that the radical concentration ranges from 10^-12mol/L to 10^-16mol/L corresponding to the radical life in 10^4s to 10^8s, which means the radicals have a long lifetime. Moreover because of the long lifetime radicals it causes a unique feature rather than the common radical polymerization, and also shows no "living polymerization". It is noticed in experiments that there are two key factors playing important roles. One is the effective radical amount produced during the plasma discharging while the another is the diffusion factor. 相似文献
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新型选择性减害滤棒的研制 总被引:4,自引:2,他引:2
为了利用天然植物活性成分的抗氧化性,对抗氧化剂葡萄多酚(PT)、苹果多酚(PG)、茶多酚(CY)进行了筛选,采取直接添加、依托载体添加及制备成颗粒复合添加等多种添加工艺,并通过对抗氧化剂改性提高其在卷烟中的添加量,制备了新型选择性减害滤棒并卷制成样品烟支,对滤棒的各项常规物理指标和卷烟烟气的常规化学指标及自由基含量的变化进行测试。同时,采用加速氧化法对该种减害滤棒的抗氧化性能的稳定性进行了检测和评价。结果表明:采用直接添加和复合添加相结合的加工工艺,当有效成分含量为90%的改性抗氧化剂CY1在滤棒中的添加量达到3.0mg/支后,能够实现选择性显著降低烟气自由基近30%,同时不影响烟支外观和烟气常规技术指标,卷烟吸味也未因此有明显改变。 相似文献
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3 低温等离子体在聚合物表面改性中的应用3 1 塑料薄膜的表面改性3 1 1 工业包装膜目前的PP、BOPE、PVC、PET等塑料薄膜,在实际应用中均存在着难印刷和难粘接问题,因此工业包装膜在印刷之前一般要进行电晕处理。更多的塑料薄膜在使用之前要涂以特种底漆,如氯化聚氯乙烯、氯化聚丙烯为主要成分的底涂剂,然后使用溶剂型的印刷油墨进行印刷。成本高是一方面,高质量高标准的印刷控制也十分不容易稳定,还有许多凹版印刷的薄膜直接应用于食品包装和日常生活用品的包装,残留的溶剂及含氯树脂所造成的污染也是不容忽视的。低温等离子体表面… 相似文献
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采用4-氨基苯基-3,5-二乙基-4-氨基苯基-9,10-二氢-9-氧杂-10-磷杂菲-10-磷酰基乙烷(ADADOPPE)和2-(4-氨基苯基)-5-氨基苯并恶唑(AAPBO)以不同摩尔比与2,3,3′,4′-联苯四甲酸二酐(α-BPDA)共聚制备一系列聚酰亚胺(PI)薄膜。通过FTIR、TGA、TMA、极限氧指数仪和UV-Vis等仪器对薄膜进行结构表征及性能研究。结果表明:含ADADOPPE不对称二胺单体的PI膜比传统PI膜有出色的透明性并具有较好力学性能,其中PI-C-3薄膜的截止波长为401.5 nm,最大透过率达到82.25%,拉伸强度为136.4 MPa。 相似文献
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用氧经还原滴定法测过氧化氢含量,是测定过氧化含量的经典方法,但存在着影响因素多,操作周期长,分析费时,费力的缺点,此法根据不同浓度的过氧化氢水溶液同一温度下的密度差别来分析过氧化氢水溶液中过氧化氢含量,分析了其可靠性,指出该方法具有准确,简便,易掌握的优点. 相似文献
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The influence of the iodine vapour pressure on the mechanisms of XeI^* formation is investigated in Xe/I2 mixture by dielectric barrier discharge. The iodine vapour pressure is measured as a function of the ultraviolet (UV) intensity of XeI^* emission at 253 nm, and found that the UV intensity reaches a maximum at 0.9 Torr of iodine at a xenon pressure of 300 Torr, then decreases slowly with the iodine pressure larger than 0.9 Torr. The discharge mode transforms from a hybrid discharge at a xenon pressure of 760 Torr with 1.0 Torr of iodine to a diffuse mode at 10 Torr of iodine. These results are quite different from those of other rare-gas halogen excimers and indicate a different mechanism of XeI^* formation from those of other rare-gas halogen excimers. 相似文献
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