英文文献翻译

1、 外文文献原稿和译文原 稿Sodium Polyacrylate:Also known as super- absorbent or “SAP”(super absorbent polymer), Kimberly Clarkused to call it SAM (super absorbent material). It is typically used in fine granular form(like table salt). It helps improve capacity for better retention in a disposable diaper,allowing

2、 the product to be thinner with improved performance and less usage of pine fluffpulp. The molecular structure of the polyacrylate has sodium carboxylate groups hangingoff the main chain. When it comes in contact with water, the sodium detaches itself, leavingonly carboxylions. Being negatively char

3、ged, these ions repel one another so that thepolymer also has cross-links, which effectively leads to a three-dimensional structure. It hashige molecular weight of more than a million; thus, instead of getting dissolved, it solidifiesinto a gel. The Hydrogen in the water (H-O-H) is trapped by the ac

4、rylate due to the atomicbonds associated with the polarity forces between the atoms. Electrolytes in the liquid, suchas salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affectingsuperabsorbent properties, especially with regard to the superabsorbent capacity for liquidretent

5、ion. This is the main reason why diapers containing SAP should never be tested withplain water. Linear molecular configurations have less total capacity than non-linearmolecules but, on the other hand, retention of liquid in a linear molecule is higher than in anon-linear molecule, due to improved p

6、olarity. For a list of SAP suppliers, please use thislink: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (withless retention) or very high retentions (but lower capacity). In addition, a surface crosslinker can be added to the superabsorbent particle to help it move liq

7、uids while it issaturated. This helps avoid formation of gel blocks, the phenomenon that describes theimpossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer Chemistry Until the 1980s, water absorbing materials were cellulosic or fiber-basedproducts. Cho

8、ices were tissue paper, cotton, sponge, and fluff pulp. The water retentioncapacity of these types of materials is only 20 times their weight at most.In the early 1960s, the United States Department of Agriculture (USDA) wasconducting work on materials to improve water conservation in soils. They de

9、veloped aresin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules(i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrileco-polymer gave water absorption greater than 400 times its weight. Also, the gel did notrelease liquid wate

10、r the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”. The USDA gave the technicalknow how several USA companies for further development of the basic technology. Awide range of grating combinations were attempted including work with acrylic acid,acrylamide and poly

11、vinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independentresearch using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol(PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry

12、 includedDow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical,Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time not for soil amendment applications as or

13、iginally intended but for disposable hygienicproducts. The first product markets were feminine sanitary napkins and adult incontinenceproducts.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbentpolymers in sanitary napkins.Super absorbent polymer was first used in Europe

14、in a baby diaper in 1982 whenSchickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter,UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble andKimberly-Clark in the USA began to use the material. The development of super absorbent technology

15、 and performance has been largely ledby demands in the disposable hygiene segment. Strides in absorption performance haveallowed the development of the ultra-thin baby diaper which uses a fraction of the materials particularly fluff pulp which earlier disposable diapers consumed.Over the years, tech

16、nology has progressed so that there is little if any starch-graftedsuper absorbent polymer used in disposable hygienic products. These super absorbentstypically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-

17、linkedacrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a superabsorbent fiber technology in the early 1990s. This technology was eventually sold toCamelot Absorbents. There are super absorbent fibers commercially availa

18、bletoday. While significantly more expensive than the granular polymers, the super absorbentfibers offer technical advantages in certain niche markets including cable wrap, medicaldevices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemicalformula -CH -CH(C

19、OONa)- widely used in consumer products. It has the ability to2nabsorb as much as 200 to 300 times its mass in water. Acrylate polymers generally areconsidered to possess an anionic charge. While sodium neutralized polyacrylates are themost common form used in industry, there are also other salts av

20、ailable includingpotassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include:Sequestering agents in detergents. (By binding hard water elements such as calciumand magnesium, the surfactants in detergents work more efficiently.)Thick

21、ening agentsCoatingsFake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to asSuper Absorbents and Water Crystals, and are used in baby diapers. Copolymer versions are used in agriculture and other specialty absorbent applications. The origins ofsuper absorbent polymer

22、 chemistry trace back to the early 1960s when the U.S. Departmentof Agriculture developed the first super absorbent polymer materials. This chemical isfeatured in the Maximum Absorbency Garment used by NASA. 译 文聚丙烯酸钠聚丙烯酸钠，又可以称为超级吸收剂或者又叫高吸水性树脂，凯博利克拉克教授曾经称它为 SAM 即：超级吸收性物质。它经常以细小颗粒的形式被应用，例如食盐。它有助于提高一次性

23、尿布的保水能力，提高该产品的使用性能，并且使该产品越做越薄。在聚丙烯酸钠分子中，羧基连接在主链上。当聚丙烯酸钠分子与水接触时，分子中钠分离出去，只剩下羧基。由于分子变成了带有负电荷的结构，所以这些离子相互排斥，使聚合物分子交叉连接从而有效地形成了三维结构。由于这种结构的分子量超过一百万，所以它并没有溶解，而是凝固成凝胶。在水分子H-O-H 中，氢原子稳定地存在于丙烯酸中是因为存在原子键，这些键与分子中的极性键密切相关。在液体中的电解质，例如矿物质盐（尿液中的含量为 0.9%）,降低电解质的极性，进而会影响吸水性，特别是对于保留高吸水性树脂的液体容量。这就是为什么含有高吸水性树脂的尿布不能仅仅用

24、水进行试验。线性分子的这种构造在总吸水量上不如非线性分子，但是另一方面，线性分子的保水性能却比非线性分子好很多，原因是极性增加提高了保水性能。超级吸收剂可以这样进行设计：它可以具有很高的吸水性但是保水性不佳，或者正相反。此外，我们可以在超级保水剂中添加表面交联剂，这是一种可以帮助水分子进行移动的添加剂。这样就可以避免形成凝胶块的形成，解决了这样一种难题：SAP分子一旦达到饱和状态，它将不再可以被移动。SAP 化学的历史直到上个世纪八十年代，吸水类物质是纤维素或纤维素类的产品。产品仅限于纸巾、棉花、海绵和绒毛浆。这些类型保水类产品的保水能力至多是它们自身质量的 20倍。在 60 年代初，美国农业

25、部开始了对吸水材料的研制工作，目的是要提高土壤的保水能力。他们开发出一种方法，可以在淀粉分子的骨干上把丙烯腈嫁接到上面，即淀粉接枝聚丙烯腈。这种淀粉和丙烯腈的聚合物淀粉接枝聚丙烯腈水解后的吸水能力可以达到 400 倍于自身的质量。但是，这种凝胶的释水能力并没有纤维素类的凝胶的 释水能力强。这种聚合物被冠以“超级吸水王”的美名。美国农业部把这项技术转让给若干家有能力继续深入研究这项基础技术的美国公司。他们进行了广泛的研究，包括把纤维素和各种物质进行组合尝试，产品有纤维素接枝聚丙烯酸，纤维素接枝丙烯酰胺和纤维素聚乙烯醇(PVA)等等。由于日本的公司被美国农业部排斥在外，他们开始独立进行这方面的研究。他们对淀粉、羧甲基纤维素 (CMC)、丙烯酸、聚乙烯醇 (PVA)和异丁烯、马来酸酐 (IMA)进行研究。在高效吸水剂化学工业发展的早期，很多大的公司参与进来，其中包括陶氏化学、大力士化学、通用米氏化学、杜邦公司，日本国民淀粉化学公司、三洋化学公司、住友化学公司、花王化学公司以及日本淀粉化学公司。在 70 年代初，高吸水性树脂不仅以前广泛应用于人们的初衷，即改善土壤保水性的领域，而且第一次被应用于商业领域：可任意使用的人们的日常卫生用品。但是第一个产品市场是女性卫生巾和成人失禁产品。1978 年，帕克戴维斯把高效吸水剂用于卫生保水领域。这是一个历史性的新突破，从此保水剂的应用迎来