核壳乳液聚合课件

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level,*,核壳乳液聚合,1,ppt课件,核壳乳液聚合,核壳乳液聚合,1,什么是核壳乳液聚合,2,核壳乳液聚合的核壳结构,3,影响核壳乳液聚合的因素,4,核壳乳液聚合运用举例,2,ppt课件,核壳乳液聚合1什么是核壳乳液聚合2核壳乳液聚合的核壳结构3影,什么是核壳乳液聚合,种子乳液聚合,所谓种子乳液聚合是先将少量单体按一般乳液聚合法制得种子胶乳(100150nm)。,然后将少量种子胶乳(1%,3%)，加入正式乳液聚合的配方中。,种子胶乳粒将被单体所溶胀并吸附水相中产生的自由基而引发聚合，经过多级溶胀聚合，使粒子逐渐增大，最终可达12m或更大。(普通50-200nm),可用来制备粒径较大、分布较窄的乳胶粒子。,在第二步反应中，要控制乳化剂的用量，以抑制新的粒子生成。,3,ppt课件,什么是核壳乳液聚合种子乳液聚合3ppt课件,什么是核壳乳液聚合,核壳乳液聚合,核壳乳液聚合是种子乳液聚合的发展。,若种子聚合和后继聚合采用不同单体，则形成核壳结构的胶粒，在核与壳的界面上形成接枝层，增加两者的相容性和粘结力，提高力学性能。,在总配比完全相同的情况下，因为组分性质的差异，采用种子乳液聚合的方法，控制不同的加料顺序和条件，可以得到结构形态不同的核壳乳胶粒子。,与普通乳液乳液聚合相比，它有显著的优越性，如在流变性、最低成膜温度、玻璃转化温度、抗张强度、粘接性能、加工性等方面有显著的特点。,4,ppt课件,什么是核壳乳液聚合核壳乳液聚合4ppt课件,什么是核壳乳液聚合,种子乳液聚合,核壳乳液聚合,使粒子长大,后继的正式聚合采用同一种单体,少量单体先形成种子胶乳,形成核壳结构,后继聚合采用不同单体,少量单体先形成核结构部分,5,ppt课件,什么是核壳乳液聚合种子乳液聚合核壳乳液聚合使粒子长大后继的正,核壳乳液聚合的核壳结构,乳胶粒的核壳结构：,在乳胶粒的中心附近是一个富聚合物的核，其中聚合物含量大而单体含量少,。,在核的外围是一层富单体的壳;在壳表面上吸附乳化剂分子而成一单分子层，以使该乳胶粒稳定的悬浮在水相中,。,在核与壳的界面上，分布有正在增长的或失去活性的聚合物末端，聚合反应就是发生在这个界面上。,6,ppt课件,核壳乳液聚合的核壳结构乳胶粒的核壳结构：6ppt课件,核壳乳液聚合的核壳结构,单体液滴,单体液滴,种子胶乳,单体、乳化剂分别处在水溶液、胶束、液滴三相中的示意图,7,ppt课件,核壳乳液聚合的核壳结构单体液滴单体液滴种子胶乳单体、乳化剂分,影响核壳乳液聚合的因素,根据核和壳单体的不同，正常的核壳聚合物基本上有两种类型：,硬核软壳型：这类聚合物主要用作涂料。,软核硬壳型：调节玻璃化温度或最低成膜温度。以丁二烯丙烯酸丁酯等软单体，经乳液聚合后为种子，甲基丙烯酸甲酯苯乙烯丙烯睛等为硬单体，后来加入继续聚合，就成为硬壳层。以B（聚丁二烯）为核，S（苯乙烯）和A（丙烯氰）共聚物为壳，就成了著名的ABS工程塑料。,8,ppt课件,影响核壳乳液聚合的因素8ppt课件,影响核壳乳液聚合的因素,核壳乳液粒子构成机理,接枝机理,一种单体在另一种聚合物存在下进行聚合时，在适当的条件下，会多去聚合物上的活泼氢原子而发生接枝共聚。如St-BA核壳乳液聚合,互穿聚合物网络机理,两种聚合物分子链相互贯穿并以化学键的方式各自交联而成的网络结构,离子键合机理不同电荷的相互作用,9,ppt课件,影响核壳乳液聚合的因素9ppt课件,影响核壳乳液聚合的因素,壳层物质的,加料方法,不同，,形成的核壳结构和核壳间结合方式也差别很大。,溶胀法,：先不补加引发剂，而加入壳单体，使壳单体,溶胀,进入乳胶内。这种方法不仅种子乳胶粒表面的单体浓度很高，而且壳单体有充分时间渗入到种子乳胶粒子内部。,间歇法,：壳单体,一次性,加入，在引发剂存在下引发聚合，这种方法也使乳胶粒表面单体浓度很高。,半连续法,：将壳单体连续滴加，使种子乳胶的表面和内部壳单体浓度都很低，既聚合物处,在饥渴状态.,此只能在核聚合物上连续形成壳层而缺乏核壳层间的结合。,10,ppt课件,影响核壳乳液聚合的因素溶胀法：先不补加引发剂，而加入壳单体，,影响核壳乳液聚合的因素,影响核壳结构的因素除了两中单体的加料次序外，还与,单体的亲水性,有关。,一般乳液聚合都以水为分散介质，亲水性较大的聚合物易和介质水接近，而疏水性倾向于排斥介质水，因而形成不同结构形态的胶乳粒子。,正常结构和非正常的结构,形态(如翻转形等)乳胶粒。,11,ppt课件,影响核壳乳液聚合的因素11ppt课件,核壳乳液聚合的应用举例（1）,多层特种结构聚合物乳胶粒子,递变进料、单体A单体B、洋葱,当R0：R1=1：2，内部富含B外部富含A的核壳聚合物；当R0,R1，无规共聚物；当R0,R1，典型的B核A壳聚合物,12,ppt课件,核壳乳液聚合的应用举例（1）多层特种结构聚合物乳胶粒子12p,核壳乳液聚合的应用举例（2）,synthesis and application of anionic acrylic,（,阴离子丙烯酸,）,emulsion used as paper wet-strength additive,13,核壳乳液聚合的应用举例（2）synthesis an,Related,imformation,Title,synthesis and application of anionic acrylic emulsion（,阴离子丙烯酸,）used as paper wet-strength additive,Authors,Xin Liu,Chunhua Tian,Yuying Wu,Xueming Zhang,College of Materials Science and Technology,Beijing Forestry University,From,4th International Conference on Pulping,Papermaking and Biotechnology,ppt课件,Related imformationTitleppt课件,Contents,1.,Abstract,2.Introduction,3.,Experienment,4.,Results and discussion,5.Conclusion,ppt课件,Contents1.Abstract2.Introduc,Abstract,polymerization,butyl,acrylate(BA)as soft monomer,styrene(St)as hard,monomer,sodium dodecyl sulfate,(SDS)and dodecyl,polyoxy ethylene(OP-10),as emulsifiers under nitrogen,丙烯酸丁酯、苯乙烯、十二烷基硫酸钠、烷基酚聚氧乙烯醚,the optimal conditions,the,ratio of SDS to OP-10 was 1:2,total dosage was,8%;,the dosage of initiator was 0.25 g,including 0.15g in,seeded polymerization process and 0.1g in shell,polymerization process;,the functional monomer,dosage was 7.5 g,.,ppt课件,Abstractppt课件,Abstract,used as,wet strength agent,single use of APSBM,（,苯乙烯-丙烯酸丁酯-甲基丙烯酸）,was not,good,simultaneous use of 0.3%APSBM and 0.7%,PAE showed great improvement of wet strength,to 38%,SEM photographs showed that,the appearance of paper,treated with,0.7%PAE and 0.3%APSBM had a close crosslinking,（交联）,ppt课件,Abstractppt课件,Introduction,background,1/,environmental,-friendly,product,s-MF,（脲-甲醛树脂）,/UF,（三聚氰胺一甲醛树脂）,/PAE,（聚酰胺环氧氯丙烷）,2/excellent penetrability,（渗透性）,affinity,（亲和力）,and,film,forming ability,;it can disperse in,water without organic solvent,3/some disadvantages:,high temperature of film forming,lower rigidity,（刚度）,tending to get soft,poor water resistance,（抗水性）,of cured,（熟化）,film,ect,4/One solution to solve above mentioned problemsis to develop special structure of particles called,core-shell structure,（核壳结构）,of the polymer particles,ppt课件,Introduction backgroundppt课,Introduction,idea,a new concept of particle design,that is,changing the structure of latex,（胶乳）,particles through,designing the,composition of core and shell,structures,of latex particles,as to,improve the properties of,emulsion,acrylate copolymer,（丙烯酸共聚物）,emulsion with,core-shell structure was prepared using styrene(St),（,苯乙烯）,as,hard monomer and butyl acrylate(BA),（,丙烯酸丁酯）,as soft,monomer.,ppt课件,Introduction idea ppt课件,Experienment,A constitutional formula synthesized by St,（,苯乙烯,）,BA,（,丙烯酸丁酯,）,and,-MAA,（,甲基丙烯酸,）,ppt课件,ExperienmentA constitutional f,Experienment,Copolymer synthesis,Seed,（种子聚合）,emulsifier,buffer and distilled water mixed seed monomers,potassium peroxydisulfate,（过硫酸钾）,Core,（核聚合）,core monomers which were well pre-emulsified,Shell,（壳聚合）,well pre-emulsified shell monomers,ppt课件,ExperienmentCopolymer synthesi,Experienment,Paper sheets preparation and analysis,hardwood bleached kraft pulp(HBKP),（阔叶木漂白硫酸盐浆）,80 g/m2 basis weight,Wet tensile strength and folding endurance,Emulsion characterization,observation of emulsions state,viscosity and color;the solid,content,conversion,mechanical stability,ionic stability,pH,stability and storing stability(one month),ppt课件,ExperienmentPaper sheets prepa,Thank You!,23,Thank You!23,Results and discussion,1/more than 98%,2/as the amount of SDS increased,the flocculation of emulsion significantly increased and the storing stability reduced,also the emulsion began to layer.,3/same charge causes the bonding of the emulsifier molecules and latex particles,to decline.,ppt课件,Results and discussion1/more t,Results and discussion,During seed reaction stage,when emulsifier dosage was 3%,the monomer conversion rate was the lowestof all;,During core reaction stage,as the reaction went on,the monomer conversion rate increased fast,especially the emulsifier dosage 3%increased significantly;,During shell reaction stage,the conversion rate increased slowly;,At the end of reaction,the conversion rates of four different emulsifier dosages system were almost the same,which could all,reach more than 99%,ppt课件,Results and discussionDuring s,Results and discussion,1/As the amount of emulsifier,increased,the reaction began to gel and the blue fluorescence became less obvious.,ppt课件,Results and discussion1/As the,Results and discussion,1/,0.00/90.49%,0.10/98.87%,0.15/98.56%,2/it need additional initiator during shell polymerization reaction,because of the,consumption during seed and core polymerization,reactions.,ppt课件,Results and discussion1/ppt课件,Results and discussion,1/when the amount of-MAA was2.5 g,the emulsion was transparent with a lower viscosity.,2/When the dosage was between 5.0 g and 10.0 g,the conversions were higher and the,stability all performed well.,ppt课件,Results and discussion1/when t,Thank You!,29,Thank You!29,