聚甲基丙烯酸甲酯的聚合研究

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1、 聚甲基丙烯酸甲酯 的聚合研究 姓 名 唐小峰 班 级 高化0801 学 院 化学与材料科学学院整理为word格式 聚甲基丙烯酸甲酯的聚合研究目录摘要2Contents3History3Synthesis4Processing4Handling, cutting, and joining4Properties5Poly(methyl acrylate)71.1前言71.2 聚甲基丙烯酸甲酯的制备71.21原料使用条件81.2.2聚甲基丙烯酸甲酯的制备81.3 PMMA的物理性能91.4 PMMA化学性能91.5 压克力性能101.6 工艺特性101.7 聚甲基丙烯酸甲酯的用途10整理为word

2、格式摘要聚甲基丙烯酸甲酯（PMMA）是由甲基丙烯酸甲酯自由聚合而成，有浇铸成型、注塑成型、挤出成型、热成型等制备方法。研究了聚甲基丙烯酸甲酯的物理化学性能以及在不同条件下制的的聚甲基丙烯酸甲酯的工艺特性。最后，介绍了聚甲基丙烯酸甲酯生产和市场现状，包括（生产厂家、产品牌号、市场消费）等。简述了聚甲基丙烯酸甲酯生产技术及市场发展并提出建议。关键词 PMMA 浇铸 注塑 挤出 热工艺特点 市场 发展Poly(methyl methacrylate) (PMMA) is a transparent thermoplastic, often used as a light or shatter-res

3、istant alternative to glass. It is sometimes called acrylic glass. Chemically, it is the synthetic polymer of methyl methacrylate. The material was developed in 1928 in various laboratories, and was first brought to market in 1933 by Rohm and Haas Company, under the trademark Plexiglas.4 It has sinc

4、e been sold under many different names including Lucite and Perspex.The often-seen spelling poly(methyl 2-methylpropanoate) with -an- is an error for poly(methyl 2-methylpropenoate), based on propenoic acid.PMMA is an economical alternative to polycarbonate (PC) when extreme strength is not necessar

5、y. Additionally, PMMA does not contain the potentially harmful bisphenol-A subunits found in polycarbonate. It is often preferred because of its moderate properties, easy handling and processing, and low cost, but behaves in a brittle manner when loaded, especially under an impact force, and is more

6、 prone to scratching compared to conventional inorganic glass.Contents 1 History o 1.1 Names 2 Synthesis 3 Processing 4 Handling, cutting, and joining 5 Acrylate resin casting 6 Properties o 6.1 Modification of properties 7 Poly(methyl acrylate) 8 Uses o 8.1 Transparent glass substitute整理为word格式 o 8

7、.2 Daylight redirection o 8.3 Medical technologies and implants o 8.4 Artistic and aesthetic uses o 8.5 Other uses 9 See also 10 References o 10.1 Bibliography o 10.2 External links HistoryThe first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865

8、. The reaction between methacrylic acid and methanol results in the ester methyl methacrylate. The German chemists Fittig and Paul discovered in 1877 the polymerization process that turns methyl methacrylate into polymethyl methacrylate. In 1933 the German chemist Otto Rhm patented and registered th

9、e brand name PLEXIGLAS. In 1936 the first commercially viable production of acrylic safety glass began. During World War II acrylic glass was used for submarine periscopes, windshields, canopies, and gun turrets for airplanes.5NamesPMMA has been sold under a variety of brand names and generic names.

10、 It is often generically called acrylic glass,6 although it is chemically unrelated to glass. It is sometimes called simply acrylic, although acrylic can also refer to other polymers or copolymers containing polyacrylonitrile. Other notable trade names include: Lucite7 Plexiglas8 Optix (Plaskolite)9

11、 Perspex10 Altuglas11unreliable source? (Arkema) SynthesisPMMA is routinely produced by emulsion polymerization, solution polymerization and bulk polymerization. Generally radical initiation is used (including living polymerization methods), but anionic polymerization of PMMA can also be performed.

12、To produce 1kg (2.2lb) of PMMA, about 2kg (4.4lb) of 整理为word格式petroleum is needed. PMMA produced by radical polymerization (all commercial PMMA) is atactic and completely amorphous.ProcessingThe glass transition temperature (Tg) of atactic PMMA is 105 C. The Tg values of commercial grades of PMMA ra

13、nge from 85 to 165 C (185to 329F); the range is so wide because of the vast number of commercial compositions which are copolymers with co-monomers other than methyl methacrylate. PMMA is thus an organic glass at room temperature i.e., it is below its Tg. The forming temperature starts at the glass

14、transition temperature and goes up from there.12 All common molding processes may be used, including injection molding, compression molding and extrusion. The highest quality PMMA sheets are produced by cell casting, but in this case, the polymerization and molding steps occur concurrently. The stre

15、ngth of the material is higher than molding grades owing to its extremely high molecular mass. Rubber toughening has been used to increase the strength of PMMA owing to its brittle behavior in response to applied loads.Handling, cutting, and joiningPMMA can be joined using cyanoacrylate cement, more

16、 commonly known as superglue, with heat (welding), or by using solvents such as di- or trichloromethane to dissolve the plastic at the joint which then fuses and sets, forming an almost invisible weld. Scratches may easily be removed by polishing or by heating the surface of the material.Laser cutti

17、ng may be used to form intricate designs from PMMA sheets. PMMA vaporizes to gaseous compounds (including its monomers) upon laser cutting, so a very clean cut is made, and cutting is performed very easily. However, the pulsed lasercutting introduces a high internal stresses along the cut edge, whic

18、h when exposed to solvents produces undesirable stress-crazing at the cut edge and several millimetres deep. Even ammonium-based glass-cleaner and almost everything short of soap-and-water produces similar undesirable crazing, sometimes over the entire surface of the cut parts, at great distances fr

19、om the stressed edge. Annealing the PMMA sheet/parts is therefore an obligatory post-processing step when intending to chemically bond lasercut parts together. This involves heating the parts in an air circulating oven from room temperature up to 90C (at a rate of no more than 18 degrees per hour) d

20、own to room temperature (at a rate of no more than 12 degrees per hour). Temperature should be maintained as follows: one hour for 3mm thickness, two hours for up to 6mm thickness, four hours for up to 12mm thickness, and six hours for up to 20mm thickness. A rapid annealing cycle is reliable for th

21、in sheets and involves placing them in a pre-heated oven to 80C for one hour, then removing parts from oven and allowing to cool to room temperature. This added time component should be factored into the whole fabrication process, and the alternative Zero-rake sawcutting technique may provide better

22、 cost-effectiveness, unless complex non-straight line edges are required. In this respect PMMA has an advantage over competing polymers such as 整理为word格式polystyrene and polycarbonate, which require higher laser powers and give more messy and charred laser cuts.In the majority of applications, it wil

23、l not shatter. Rather, it breaks into large dull pieces. Since PMMA is softer and more easily scratched than glass, scratch-resistant coatings are often added to PMMA sheets to protect it (as well as possible other functions).Methyl methacrylate synthetic resin for casting (simply the bulk liquid ch

24、emical) may be used in conjunction with a polymerization catalyst such as MEKP, to produce hardened transparent PMMA in any shape, from a mold. Objects like insects or coins, or even dangerous chemicals in breakable quartz ampules, may be embedded in such cast blocks, for display and safe handling.P

25、ropertiesSkeletal structure of methyl methacrylate, the monomer that makes up PMMAPMMA is a strong and lightweight material. It has a density of 1.171.20g/cm3,113 which is less than half that of glass.1 It also has good impact strength, higher than both glass and polystyrene; however, PMMAs impact s

26、trength is still significantly lower than polycarbonate and some engineered polymers. PMMA ignites at 460 C (860F) and burns, forming carbon dioxide, water, carbon monoxide and low molecular weight compounds, including formaldehyde.14整理为word格式PMMA transmits up to 92% of visible light (3mm thickness)

27、, and gives a reflection of about 4% from each of its surfaces on account of its refractive index (1.4914 at 587.6nm).3 It filters ultraviolet (UV) light at wavelengths below about 300 nm (similar to ordinary window glass). Some manufacturers15 add coatings or additives to PMMA to improve absorption

28、 in the 300400nm range. PMMA passes infrared light of up to 2800nm and blocks IR of longer wavelengths up to 25000nm. Colored PMMA varieities allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example).PMMA swells and dissolves in

29、many organic solvents; it also has poor resistance to many other chemicals on account of its easily hydrolyzed ester groups. Nevertheless, its environmental stability is superior to most other plastics such as polystyrene and polyethylene, and PMMA is therefore often the material of choice for outdo

30、or applications.16PMMA has maximum water absorption ratio of 0.30.4% by weight.13 Tensile strength decreases with increased water absorption.17 Its coefficient of thermal expansion is relatively high as (510)105 /K.18Modification of propertiesPure poly(methyl methacrylate) homopolymer is rarely sold

31、 as an end product, since it is not optimized for most applications. Rather, modified formulations with varying amounts of other comonomers, additives, and fillers are created for uses where specific properties are required. For example,A small amount of acrylate comonomers are routinely used in PMM

32、A grades destined for heat processing, since this stabilizes the polymer to depolymerization (unzipping) during processing. Comonomers such as butyl acrylate are often added to improve impact strength. omonomers such as methacrylic acid can be added to increase the glass transition temperature of th

33、e polymer for higher temperature use such as in lighting applications. Plasticizers may be added to improve processing properties, lower the glass transition temperature, or improve impact properties. 整理为word格式Dyes may be added to give color for decorative applications, or to protect against (or fil

34、ter) UV light. Fillers may be added to improve cost-effectiveness. Poly(methyl acrylate)The polymer of methyl acrylate, PMA or poly(methyl acrylate), is similar to poly(methyl methacrylate), except for the lack of methyl groups on the backbone carbon chain.19 PMA is a soft white rubbery material tha

35、t is softer than PMMA because its long polymer chains are thinner and smoother and can more easily slide past each other.1.1前言 聚甲基丙烯酸甲酯英文名称：PolymethylMethacrylate简称（PMMA），PMMA树脂是无毒环保的材料，可用于生产餐具，卫生洁具等，具有良好的化学稳定性、和耐候性。 PMMA树脂在破碎时不易产生尖锐的碎片，美国、日本等国家和地区已在法律中作出强制性规定，中小学及幼儿园建筑用玻璃必须采用PMMA树脂。 目前，全国各地加快了城市建设步

36、伐，街头标志、广告灯箱和电话亭等大量出现，其中所用材料中有相当一部分是PMMA树脂。北京奥运工程的户外彩色建材也大量使用了绿色环保的PMMA树脂。 聚甲基丙烯酸甲酯主要用于汽车工业（信号灯设备、仪表盘等），医药行业（储血容器等），工业应用（影碟、灯光散射器），电子产品的按键(特别是透明的）。日用消费品（饮料杯、文具等）。 PMMA溶于有机溶剂，如苯酚PMMA物理性能，苯甲醚等，通过旋涂可以形成良好的薄膜，具有良好的介电性能，可以作为有机场效应管（OFET）亦称有机薄膜晶体管（OTFT）的介质层。 1.2 聚甲基丙烯酸甲酯的制备 聚甲基丙烯酸甲酯是由甲基丙烯酸甲酯自由聚合而成，产品包括PMMA板

37、材（浇铸.挤出）和PMMA模塑料。 PMMA大单体，丙烯酸经溶液聚合而制的，丙烯酸与甲基丙烯酸无规共聚物，由丙烯酸及甲基丙烯酸甲酯在偶氮二异丁腈作用下经溶液聚合而得；其他试剂为化学剂。 1.21原料使用条件 聚甲基丙烯酸甲酯，使用前经减压蒸馏提纯；硫基乙醇直接使用；偶氮二异丁腈用无水乙醇重结晶后真空室温干燥；然后密封保存待用；四氢呋喃使用前用钠丝回流78小时，常压蒸馏待用；丙烯酰氯使用前加铜粉减压蒸馏，密封并放置冰箱中待用；三乙胺使用前钠丝回流78小时，常压蒸馏待用；石油醚沸程6090整理为word格式；苯甲苯均为市售。1.2.2聚甲基丙烯酸甲酯的制备A:浇铸成型浇铸成型用于成型有机玻璃板材、

38、棒材等型材，即用本体聚合方法成型型材。浇铸成型后的制品需要进行后处理，后处理条件是60下保温2h， 120下保温2h 。B注塑成型注塑成型采用悬浮聚合所制得的颗粒料，成型在普通的柱塞式或螺杆式注塑机上进行。下面是聚甲基丙烯酸甲酯注塑成型的典型工艺条件。 工艺参数螺杆式注塑机 柱塞式注塑机 料筒温度 后部 180-200 180-200 中部 190-230 前部 180-210 210-240 喷嘴温度 180-210 210-240 模具温度 40-80 40-80 注射压力MPa 80-120 80-130 保压压力MPa 40-60 40-60 螺杆转速rp.m-1 20-30 注塑制品

39、也需要后处理消除内应力，处理在70-80热风循环干燥箱内进行，处理时间视制品厚度，一般均需4h左右。 C挤出成型聚甲基丙烯酸甲酯也可以采用挤出成型，用悬浮聚合生产的颗粒料制备有机玻璃板材、棒材、管材、片材等，但这样制备的型材，特别是板材，由于聚合物分子量小，力学性能、耐热性、耐溶剂性均不及浇注成型的型材，其优点是生产效率高，特别是对于管材和其它用浇注法时模具。难以制造的型材。挤出成型可采用单阶或双阶排气式挤出机，螺杆长径比一般在20-25。表2是挤出成型的典型工艺条件。 工艺参数 片材 棒材 螺杆压缩比 2 2 料筒温度 后部 150-180 150-180 中部 170-200 170-20

40、0 前部 170-230 170-200 挤出压力MPa 28-124 07-34 进料口温度 50-80 50-80 口模温度 180-200 170-190 D热成型热成型是将有机玻璃板材或片材制成各种尺寸形状制品的过程，将裁切成要求尺寸的坯料夹紧在模具框架上，加热使其软化，再加压使其贴紧模具型面，得到与型面相同的形状，经冷却定型后修整边缘即得制品。加压可采用抽真空牵伸或用对带有型面的凸模直接加压的方法。热成型温度可参照表3推荐的温度范围。采用快速真空低牵伸成型制品时，宜采用接近下限温度，成型形状复杂的深度牵伸制品时宜采用接近上限温度，一般情况下采用正常温度。 整理为word格式1.3 P

41、MMA的物理性能 1. PMMA的密度比玻璃低：PMMA的密度大约在 1150-1190 kg/m3，是玻璃(2400-2800 kg/m3)的一半； 2. PMMA的重量较轻：PMMA的密度为1.19g/cm3，同样大小的材料，其重量只有普通玻璃的一半，金属铝（属于轻金属）的43%。 3. PMMA的机械强度较高：有机玻璃的相对分子质量大约为200万，是长链的高分子化合物，而且形成分子的链很柔软，因此，有机玻璃的强度比较高，抗拉伸和抗冲击的能力比普通玻璃高718倍。有一种经过加热和拉伸处理过的有机玻璃，其中的分子链段排列得非常有次序，使材料的韧性有显著提高。用钉子钉进这种有机玻璃，即使钉子穿

42、透了，有机玻璃上也不产生裂纹。这种有机玻璃被子弹击穿后同样不会破成碎片。因此，拉伸处理的有机玻璃可用作防弹玻璃，也用作军用飞机上的座舱盖 4. PMMA的熔点较低：PMMA的熔点约130140 C (265285 F)比玻璃约1000度的高温低很多。 5. PMMA的透光率较高 6. 可见光：PMMA是目前最优良的高分子透明材料，透光率达到92%，比玻璃的透光度高。 7. 紫外光：石英能完全透过紫外线，但价格高昂，普通玻璃只能透过0.6%的紫外线，但PMMA却能透过73%。PMMA不能滤除紫外线(UV)。紫外光会穿透PMMA，部份制造商2在PMMA表面进行镀膜，以增加其滤除紫外光的效果和性质。

43、另一方面，在照射紫外光的状况下，与聚碳酸酯相比，PMMA具有更佳的稳定性。 8. 红外线：PMMA允许小于2800nm波长的红外线通过。更长波长的IR，小于25,000nm时，基本上可被阻挡。存在特殊的有色PMMA，可以让特定波长IR透过，同时阻挡可见光(应用于远程控制或热感应等)。 1.4 PMMA化学性能 聚甲基丙烯酸甲酯为无色液体，具有香味，沸点101，密度为0.940克/厘米3(25)。工业上是先用丙酮氰醇法或异丁烯催化氧化法制出甲基丙烯酸，然后酯化而得。它容易聚合,需要在5以下存放,或加入0.01%左右的对苯二酚阻聚剂来保存。使用前将其蒸馏，把阻聚剂分出。 整理为word格式 聚甲基

44、丙烯酸甲酯能溶于自身单体、氯仿、乙酸、乙酸乙酯、丙酮等有机溶剂。由于它能溶于自身单体中，它的本体聚合物非常透明它的铸板聚合物的数均分子量一般为2.2104，相对密度为1.191.20，折射率为1.4821.521，吸湿度在0.5%以下，玻璃化温度为105。 它的抗拉强度为67千克力/毫米2,耐压强度为1214千克力/毫米2,耐冲击性比聚苯乙烯好；透光性很好，并能透过90%以上的紫外线（普通玻璃几乎不透过紫外线）；耐光老化性优异，在户外放置数年而不着色；它还有不易破碎的特点。 1.5 压克力性能透明度优良，有突出的耐老化性； 它的比重不到普通玻璃的一半，抗碎裂能力却高出几倍；它有良好的绝缘性和机

45、械强度；对酸、碱、盐有较强的耐腐蚀性能；且又易加工；可进行粘接、锯、刨、钻、刻、磨、丝网印刷、喷 砂等手工和机械加工，加热后可弯曲压模成各种压克力制品。1.6 工艺特性 聚甲基丙烯酸甲酯含有极性侧甲基，具有较明显的吸湿性，吸水率一般在0.30.4，成型前必须干燥。 聚甲基丙烯酸甲酯在成型加工的温度范围内具有较明显的非牛顿流体特性，溶液黏度随剪切速率增大会明显下降，熔体黏度对温度的变化也很敏感。因此，对于聚甲基丙烯酸甲酯的成型加工提高成型压力和温度都可明显降低熔体黏度，取得较好的流动性。聚甲基丙烯酸甲酯开始流动的温度约160，开始分解低温度约高于270，具有较宽的加工温度区域。 聚甲 基丙烯酸甲

46、酯熔体黏度较高，冷却速度又较快，制品容易产生内应力，因此成型时对工艺条件控制要求严格，制品成型后也需要后处理。聚甲基丙烯酸甲酯是无定形聚合物，收缩率及其变化范围都较小，一般约在050.8，有利于成型出尺寸精度较高的塑键。聚甲基丙烯酸甲酯切削性能较好，其型材可很容易的机加工为各种要求的尺寸。1.7 聚甲基丙烯酸甲酯的用途聚甲基丙烯酸甲酯作为性能优异的透明材料广泛应用在以下各方面：1灯具、照明器材，例如各种家用灯具、荧光灯罩、汽车尾灯、信号灯、路标。 2光学玻璃，例如制造各种透镜、反射镜、棱镜、电视机荧屏、菲涅耳透镜、相机透光零。 整理为word格式3制备各种仪器仪表表盘、罩壳、刻度盘。 4制备光

47、导纤维。 5商品广告橱窗、广告牌。 6飞机座舱玻璃、飞机和汽车的防弹玻璃（需带有中间夹层材料）。 7各种医用、军用、建筑用玻璃。1.8 参考文献1 杨启彪，杨自善，高分子材料科学与工程，1994（3），134137.2 Gilman.K.F and Senogles,E.Polymer.Letter 1967.5.4773 PARNELL.S,MIN K.Reaction kinetics.of thermoplastic polyurethane polymerizatioa in situ with poly(vinyl.choride) J .Polymer,2005,(46);3626

48、-36484 彭顺金，陈正国等，应用化学，1998（5）80825 陈万友，吕杰，聚甲基丙烯酸甲酯塑料生产技术与市场需求J，弹性体，2009，19（4）；70736 谢洪良，化工学报，2003；3792837 钱君，赢创工业扩增PMMA能力J中外能源，2011，16（2）；288 ROGUISKAM,KULTYS.A.Studies on therrfthanes based on new diphenylethance derivative diols J.Eur Polym J,2007,(4);14021403 友情提示：本资料代表个人观点，如有帮助请下载，谢谢您的浏览！ 整理为word格式