【摘要】2013英语四六级在即，精品学习网小编在此为大家编辑了“英语六级外刊阅读练习：塑料旧法新用”，供大家参考，希望对四六级考生有所帮助。祝大家取得理想的成绩!
本篇阅读材料“塑料 旧法新用”选自《经济学人》(原文标题：Science and Technology Plastics There and back again)，如果大家觉得比较简单，就当作泛读材料了解了解，认识几个新单词或新表达方式也不错。如果大家觉得这些材料理解上有难度，不妨当做挑战自己的拔高训练，希望大家都有进步。
Science and Technology Plastics There and back again
科技 塑料 旧法新用
An old idea may help solve the problem of plastic waste
一个老方法也许可以帮助解决塑料垃圾的问题
PLASTICS were once regarded as wonder-materials. They are still ubiquitous, but find less favour than they used to because of the very stability and persistence that won them plaudits in the first place. Persistence is not a quality to be desired in something that gets thrown away, and so much plastic is used in packaging, and in articles that are disposable, that many people now see conventional petrochemical plastics as a nuisance and a threat.
塑料曾一度被认为是材料中的奇迹。如今，塑料仍然无处不在，但是正是由于起初为它们赢得掌声的稳定和持久性，使得它们不再拥有当初的追捧。对于一些会被丢弃的物品来说，持久性并不是一种值得拥有的性质，而且塑料被大量使用在包装袋以及一次性物品中。目前，常规石油化工塑料已经被看做是一种公害和威胁。
The search is on, then, for biodegradable alternatives. One possibility has recently been explored by David Schiraldi of Case Western Reserve University, in Ohio, and his colleagues. They propose to reach back into history and revive the use of a feedstock that was used to make some of the first plastics invented: milk.
此后，寻找生物可降解替代品的研究一直在持续。最近，俄亥俄州凯斯西储大学的David Schiraldi及其同事已开辟了一条潜在途径。他们追溯历史并改良了塑料在发明之初时所使用的原料---牛奶的使用方法。
What they actually suggest is using casein, the principal protein found in milk. The curds (of "curds and whey") are mostly made of this protein. In 1889 a French chemist called Jean-Jacques Trillat discovered that if casein is treated with formaldehyde the result is a hard, shinysubstance that does well as a substitute for materials like ivory and tortoiseshell. Sowidespread was the enthusiasm for the new material that Queen Mary herself ordered several pieces of jewellery made from it. However, casein-based plastic of this sort is too brittle for general use. It was eventually superseded by the modern, petrochemical variety, andmanufacture stopped altogether by the 1970s.
事实上，他们的建议就是使用牛奶中的主要蛋白质---酪蛋白，凝乳(凝乳及乳清)中的大部分成分都是由酪蛋白组成。1889年，法国化学家Jean-Jacques Trillat发现被甲醛处理过的酪蛋白会生成一种坚硬而有光泽的物质，并可以作为铁及龟甲类材料的替代品。之后，这种新材料受到了广泛的热衷以至于玛丽女王自己都定制了一些用这种材料制作的珠宝。但是，这类酪蛋白塑料由于过于脆弱而无法成为一种通用材料。其最终被现代石油化工衍生物所超越，并在20世纪70年代全面停产。