16单元丁苯橡胶.

1、UNIT 16 Styrene-Butadiene Copolymer,丁二烯-苯乙烯共聚物,组员：夏毓霜，武文美，王晶晶,简介,丁苯橡胶（ Styrene-Butadiene Copolymer ），简称SBR. 最早工业化的合成橡胶之一 由丁二烯和苯乙烯两种单体共聚而得到的弹性体 为浅黄褐色弹性固体 一种综合性能较好的通用型合成橡胶 合成橡胶中产量最大的一个品种，约占整个合成橡胶产量的60%,发展史,发展史,高温丁苯橡胶,20世纪50年代生产了5摄氏度下聚合的低温丁苯橡胶,20世纪60年代初以烷基锂为引发剂用溶液聚合法制备,1933年德国首先用乙炔为原料制得丁苯橡胶,1942年美国以石油为

2、原料生产丁苯橡胶,分类,应用,主要用于制作轮胎,Words and Expressions,tread tred n.;v 踩，踏 Recipe respi n. 配方 N-dodecyl mercaptan 正十二烷基硫醇 Potassium peroxydisulfate 过硫酸钾 Flake flek n. 薄片 Short-stop n. 终止剂 Hydroquinone hadrkwnn n. 对苯二酚 Quench kwent v. 熄灭，抑制 Flash distillation n. 闪蒸 Antioxidant ntiksdn n.抗氧剂,Phenyl fenl n.苯基 N

3、aphthylamine nflemn n.萘胺 Latex leteks n.胶乳，乳液 Coagulate kgjulet v. 凝聚 Brine bran n.盐水 Sulfuric acid n. 硫酸 Crumb krm n. 碎屑，团粒 Bale bel v. 打包 Abnormal bn:ml a.反常的 Extender kstend n. 添加物剂，增量剂 sacrifice skrfas v.牺牲，损失,lighter-colored 浅色的 dithiocarbamate daaok:bmet n. 二硫代氨基甲酸盐 Chain-transfer agent 链转移剂 O

4、bjectionable a. 反对的，使人不愉快的 Dimethydithiocarbamate n. 二甲基二硫代氨基甲酸盐 Sodium sodim n. 钠 Tert-dodecyl mercaptan n. 特十二烷基硫醇 Diisopropylbenzene n. 二异丙苯 Ferrous sulfate heptahydrate n. 硫酸亚铁七水合物,Pyrophosphate parfsfet n.焦磷酸盐 Aluminum sulfate n.硫酸铝 Ethylenediaminetetraacetate n.乙二胺四乙酸盐 Dece- 构十 Tetra- 构四 Forma

5、ldehyde f:rmldhad n.甲醛 Sulfoxylate slfkslet n.次硫酸盐 Rosin acid n.松香酸 Dissociation dsosien n.分裂、分离、离解 Persulfate pslfet n.过硫酸盐 Menthane menen n.薄荷烷 Redox ridks n.氧化还原作用,The synthetic rubber industry, based on the free-radical emulsion process, was created almostovernight during World War II. Styrene-b

6、utadiene (GR-S) rubber crated at that time gives such good tire treads that natural rubber has never regained this market.,合成橡胶工业，以自由基乳液过程为基础，在第二次世界大战期间几乎很快地形成。那时，丁苯橡胶制造的轮胎性能相当优越，使天然橡胶在市场黯然失色。,The GR-S standard recipe is 丁苯橡胶的标准制法是,混合物在搅拌下50加热，每小时转化5%6%，在转化率达70%75%时通过加入“终止剂” 聚合反应终止，例如对苯二酚（大约0.1的重量百分

7、含量），抑制自由基并避免过量支化和微凝胶形成。,This mixture is heated with stirring and at 50 gives conversions of 5%6% per hour .Polymerization is terminated at 70%75% conversion by addition of “short-stop”, such as hydroquinone (approximately 0.1 part),to quench radicals and prevent excessive branching and microgel form

8、ation.,Unreacted butadiene is removed by flash distillation, and syrene by steam-stripping in a column. After addition of an antioxidant, such as N-phenyl-naphthylamine (PBNA) (1.25 parts), the latex is coagulated by the addition of brine, followed by dilute sulfuric acid or aluminum sulfate. The co

9、agulated crumb is washed, dried, and baled for shipment.,未反应的丁二烯通过闪蒸去除，苯乙烯在萃取塔中通过蒸汽萃取（剥离）。在加入抗氧剂后，例如N-甲基-萘胺（1.25的重量百分含量），加入盐水，其次加入稀释的硫酸或硫酸铝后乳液凝胶。凝胶碎片被洗涤、干 燥 并 包 装 装 运。,今天这种生产过程仍是胶体聚合反应的基础。如图16.1所示一个重要的进步是连续操作；也采用计算机模型描述。,This procedure is still the basis for emulsion polymerization today .An importa

10、nt improvement is continuous processing illustrated in Fig.16.1;computer modeling has also been described.,Inthecontinuousprocess,styrene,butadiene,soap,in-itiator,andactivator(anauxiliaryinitiatingagent)arepumpedcontinuouslyformstoragetanksthrou-ghaseriesofagitatedreactorsatsucharate that the desir

11、ed degree of conversion is reached at the last reactor. Shortstop is added, the latex warmed with steam, and the unreacted butadiene flashed off. Excess styrene is steam-stripped, and the latex finished as shown in Fig. 16.1.,在连续操作中，苯乙烯、丁二烯、肥皂、引发剂和活化剂（一种助引发剂）用泵从储罐通过一系列的混合反应器，泵送流率根据末釜的转化率控制。加入终止剂，乳液用

12、蒸气加热，未反应的丁二烯被闪蒸。剩余的苯乙烯被蒸气剥离，如图14.1表示乳液完成。,SBR prepared from the original GR-S recipe is often called hot rubber; cold rubber is made at 5 by using a more active initiator system. Typical recipes are given in Table 14.1 At 5 ,60% conversion to polymer occurs in 1215h.,由常规丁苯制法制备的丁苯胶常称作热胶；冷胶通过使用一种更高活性的

13、引发体系在5制成。典型的配方在表14.1中给出。5、60%转化率、1215 h聚合物形成。,丁二烯,苯乙烯,特十二烷基硫醇,过氧化二异丙苯,过氧化薄荷烷,硫酸亚铁七水合物,焦磷酸钾,磷酸钠十水合物 乙二胺四乙酸钠,甲醛次硫酸钠,松香酸,ColdSBRtiretreadsaresuperiortothoseofhotSBR.Polymerswithabnormallyhighmolecularweight(andconsequentlytootoughtoprocessbyordinaryfactoryequipment)canbeprocessedaftertheadditionofupto

14、50partsofpetroleum-baseoilsperhundredpartsofrubber(phr).,冷丁苯橡胶轮胎优于那些热丁苯胶。具有异常高的分子量的聚合物（因此采用常规的工厂设备由于太粘稠而难以加工）在每一百份的橡胶中加入大于50份的石油基础油后能够加工。,These oil extenders make the rubbers more processible at lower cost and with little sacrifice in properties; they are usually emulsified and blended with the late

15、x before coagulation.,这些油添加剂使橡胶更易加工体现在低成本和性能方面低损耗；他们在凝胶之前通常乳化并与胶乳混合。,Recent trends have been toward products designed for specific uses. The color of SBR, which is important in many nontire uses, has been improved by the use of lighter-colored soaps, shortstops, antioxidants, and extending oils. For

16、 example, dithiocarbamates are substituted for hydroquinone as shortstop; the latter is used on hot SBR where dark color is not objectionable.,最近倾向于设计特殊用途的产品。丁苯橡胶的颜色，在许多非轮胎使用中十分重要，通过使用浅色的肥皂、终止剂、抗氧剂和扩展油加以改进。例如，二硫化氨基甲酸盐替代对苯二酚作为终止剂；后者适用于不被人反对的黑色丁苯橡胶。,A shortstop such as sodium dimethyldithiocarbamate i

17、s more effective in terminating radicals and destroying peroxides at the lower temperatures employed for the cold rubbers.,在冷胶的制备中如二硫化氨基甲酸钠的终止剂在低温情况下对终止自由基和消灭过氧化物更有效。,Free-radical dissociative initiators that function by dissociation of a molecule or ion into two radical species are normally limited

18、 to inorganic persulfates in the case of butadiene polymerization.,在丁二烯聚合反应过程中自由基分解的引发剂即一分子分解或离子成两个自由基物种的引发剂通常限制于过硫酸盐。,The other important class of free-radical initiators, redox systems, contain two or more components that react to produce free radicals. Dodecyl mercaptan added to control molecular weight also appears to aid free-radical formation by reaction with persulfat