在水存在下的乳液和懸浮聚合已廣泛用于 PVDF 及其共聚物的實(shí)驗(yàn)室和工業(yè)。通過(guò)使用水溶性引發(fā)劑，例如過(guò)硫酸銨或2,2'-偶氮二異丁脒鹽酸鹽，在水中引發(fā)懸浮聚合。氧化還原引發(fā)劑，如過(guò)硫酸鉀-焦亞硫酸鈉或過(guò)硫酸銨-亞硫酸鈉等也已被采用。較高的壓力有利于快速聚合、增加分子量和提高引發(fā)劑的效率。在乳液聚合中，全氟羧酸或全氟烷基丙胺的陽(yáng)離子表面活劑用作乳化劑。種子乳液聚合可產(chǎn)生 Junas 膠乳納米粒子，其中交聯(lián)的膠乳粒子被可混溶的單體溶脹，然后進(jìn)行聚合。
Emulsion and suspension polymerization in the presence of water have been widely used in the laboratory and industrial production of PVDF and its copolymers. Suspension polymerization is initiated in water by using a water-soluble initiator, such as ammonium persulfate or 2,2 '- azodiisobutymidine hydrochloride. Redox initiators, such as potassium persulfate sodium pyrosulfite or ammonium persulfate sodium sulfite, have also been used. Higher pressure is conducive to rapid polymerization, increase molecular weight and improve the efficiency of initiator. In emulsion polymerization, perfluorocarboxylic acid or perfluoroalkyl propyl amine cationic surface active agent is used as emulsifier. Seed latex polymerization can produce Junas latex nanoparticles, wherein the cross-linked latex particles are first swollen by miscible monomers and then polymerized.
反應(yīng)擠壓
Extrusion reaction
淀粉和聚（丙烯酰胺）的混合物
Mixture of starch and poly (acrylamide)
淀粉-聚（丙烯酰胺）共聚物已通過(guò)與過(guò)硫酸銨反應(yīng)擠出制備的擠出溫度對(duì)丙烯酰胺的轉(zhuǎn)換沒(méi)有顯著影響。
Starch poly (acrylamide) copolymer has been prepared by reactive extrusion with ammonium persulfate. The extrusion temperature has no significant effect on the conversion of acrylamide.
對(duì)于各種底物的接枝，過(guò)硫酸銨、硝酸鈰銨或硫酸亞鐵銨/過(guò)氧化氫可用作引發(fā)劑。
For the grafting of various substrates, ammonium persulfate, ammonium ceric nitrate or ammonium ferrous sulfate / hydrogen peroxide can be used as initiators.
當(dāng)單體與淀粉的比例高時(shí)，獲得更多更高分子量的接枝。低水分含量導(dǎo)致較高分子量的接枝較少。
When the ratio of monomer to starch is high, more grafting with higher molecular weight can be obtained. Low moisture content leads to less grafting with higher molecular weight.
使用含有 23%直鏈淀粉的未改性和陽(yáng)離子馬齒淀粉和含有 2% 直鏈淀粉的蠟質(zhì)玉米淀粉檢測(cè)了陽(yáng)離子淀粉改性的效。與未改性淀粉相比，陽(yáng)離子淀粉接枝共聚物通常具有較低的分子量，但直鏈淀粉的含量沒(méi)有顯著影響。
The modification effect of cationic starch was tested by using unmodified and cationic horsetooth starch containing 23% amylose and waxy corn starch containing 2% amylose. Compared with unmodified starch, cationic starch graft copolymers usually have lower molecular weight, but the content of amylose has no significant effect.
淀粉的陽(yáng)離子改性增強(qiáng)了接枝位點(diǎn)的形成。通過(guò)這種方式，可以定制淀粉改性的聚（丙烯酰胺）共聚物的性能。
Cationic modification of starch enhanced the formation of graft sites. In this way, the properties of starch modified poly (acrylamide) copolymer can be customized.
含氟聚合物的制備、結(jié)構(gòu)與性能
Preparation, structure and properties of fluoropolymers
異相合成
Heterogeneous synthesis
在水存在下的乳液和懸浮聚合已廣泛用于 PVDF 及其共聚物的實(shí)驗(yàn)室和工業(yè)。通過(guò)使用水溶性引發(fā)劑，例如過(guò)硫酸銨或2,2'-偶氮二異丁脒鹽酸鹽，在水中引發(fā)懸浮聚合。氧化還原引發(fā)劑，如過(guò)硫酸鉀-焦亞硫酸鈉或過(guò)硫酸銨-亞硫酸鈉等也已被采用。較高的壓力有利于快速聚合、增加分子量和提高引發(fā)劑的效率。在乳液聚合中，全氟羧酸或全氟烷基丙胺的陽(yáng)離子表面活性劑用作乳化劑。種子乳液聚合可產(chǎn)生 Junas 膠乳納米粒子，其中交聯(lián)的膠乳粒子被可混溶的單體溶脹，然后進(jìn)行聚合。
Emulsion and suspension polymerization in the presence of water have been widely used in the laboratory and industrial production of PVDF and its copolymers. Suspension polymerization is initiated in water by using a water-soluble initiator, such as ammonium persulfate or 2,2 '- azodiisobutymidine hydrochloride. Redox initiators, such as potassium persulfate sodium pyrosulfite or ammonium persulfate sodium sulfite, have also been used. Higher pressure is conducive to rapid polymerization, increase molecular weight and improve the efficiency of initiator. In emulsion polymerization, perfluorocarboxylic acid or perfluoroalkyl propyl amine cationic surfactants are used as emulsifiers. Seed latex polymerization can produce Junas latex nanoparticles, wherein the cross-linked latex particles are first swollen by miscible monomers and then polymerized.
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