代写范文

留学资讯

写作技巧

论文代写专题

服务承诺

资金托管
原创保证
实力保障
24小时客服
使命必达

51Due提供Essay,Paper,Report,Assignment等学科作业的代写与辅导,同时涵盖Personal Statement,转学申请等留学文书代写。

51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标

私人订制你的未来职场 世界名企,高端行业岗位等 在新的起点上实现更高水平的发展

积累工作经验
多元化文化交流
专业实操技能
建立人际资源圈

Plastic_Chemistry

2013-11-13 来源: 类别: 更多范文

Plastic Chemistry An Introduction to Plastic The use of plastics is forever increasing from the days in which it was first invented. Not only does plastic now replace materials such as metal, glass, ceramics, wood, and paper in a wide variety of ways, there are new roles which only plastic can fill. Plastics are polymers. These are large, long molecules constructed of smaller, shorter molecules called monomers. Polymers can be natural or synthetic. Natural polymers are common in animals and plants, such as with proteins in animals and carbohydrates in plants. Synthetic polymers however, are made mainly from petroleum. This is processed in an oil refinery to produce basic chemicals known as monomers. The monomers are then turned into polymers. Some polymers are turned into solid plastic materials and others into textile fibers. Plastic was first made in 1869 when John W. Hyatt created celluloid (Dorin et al. 64). It was used to make objects such as ornaments, knife handles, cuffs, collars, and film for movies. Today, there are over seven hundred different types of plastic used to produce both hi-tech and everyday objects. The raw material for plastics is crude oil, a complex mixture of thousands of compounds. In order to plastic, polymers, plastics, form, molecules, made, polymer, between, shape, chains, mold, make, heated, compounds, different, small, process, two, together, oil, monomers, fractions, bonds, pressure, polymerization, material, reaction, ways, way, tube, thermosetting, thermoplastic, synthetic, recycling, products, produce
上一篇:Capital_Punishment__A_Look_Int 下一篇:Endoplasmic_Reticulum