【正文】 d tracks, for example, city transportation systems are being quieter and smoother. Impactresistant bumpers, shockabsorbing interiors, and crashresistant fuel tanks on cars and trucks help prevent highway deaths and injuries. Rubber 南華大學(xué)九九級化學(xué)工程與工藝專業(yè)畢業(yè)論文 第 21 頁 共 27 頁 linings in reservoirs and waste ditches reduce ground and water pollution. Latex is even being used to help stabilize desert soils to make them suitable for agricultural uses. In addition, researchers are studying the fundamental relationships between chemical structures and the features of rubbers of rubber’s macroscopic materials. Such knowledge will enable researchers to design and create specific rubber pounds rather than rely on the timeconsuming methods of trial and error. The handing and recycling of spent tires are a significant and worldwide problem. Billions of discarded tires are currently stockpiled around the world and hundreds of millions are added every year. Those tire stockpiles percent both and environmental hazards. Provided that efficient methods for recycling rubber can be developed, the spent tires could constitute a great asset as a source of raw material .The current usage of spent rubber tires is mainly confined to the production of tirederived fuel for power plants and cement kilns. From an economic and environmental perspective the reuse of rubber material should be preferable to deposition or incineration. A small part of the tire stock is ground and mixed with new rubber. Only a few percent of ground rubber material can be incorporated in the new rubber before critical properties such as modulus and tearstrength are seriously affected. The resulting material has somewhat impaired mechanical properties and this limits potential application areas. The impaired properties are mainly due to the scarcity and weakness of bonds between the crumbs and the new rubber matrix. One possible way to overe this problem is to break the sulfur bridges in the surface of the vulcanized rubber, thereby making the hydrocarbon chains more flexible and increasing the number of reactive sites. The surface of the rubber crumbs will then be transformed from an elastic to a viscous state. It has been shown that it is possible to use sulfuroxidizing microanisms for desulfurization of rubber material. These microanisms oxidize sulfur to sulfate and may break the sulfur bridges in the rubber material. Today, all the 南華大學(xué)九九級化學(xué)工程與工藝專業(yè)畢業(yè)論文 第 22 頁 共 27 頁 countries put their efforts on the research with lots of money. Under the leadership of the Central Committee of the Party, China’s rubber industry is developing at a high speed, the rubber industry workers and technicians have made many innovations. They have expanded many old plants and built up many new ones. they have also improved the quality and increased the varieties of the products. The local rubber industry has grown. the rapid growth of the local rubber industry has played an important part in the development of the whole rubber industry. Rubber industry plays an important part in our socialist construction: In old days, there was little modern rubber industry. There were few large chemical works. Most of the raw materials came from abroad. But great changes have taken place. The rubber industry has developed at a high speed. Large and small chemical works have gone up here and there. The out put of rubber products have caught up with advanced world levels. In recent years, we have brought the development of rubber industry to a new stage. Thanks to the guidance of the party’s correct line, the rubber workers and technicians have made a lot of new products. Our rubber industry will surely make still greater advances. 南華大學(xué)九九級化學(xué)工程與工藝專業(yè)畢業(yè)論文 第 23 頁 共 27 頁 譯文： 橡膠 兩百年前，英國化學(xué)家約瑟夫 所有橡膠材料都是由幾百萬個長長的、纏繞的聚合物分子組成的。 天然橡膠的另一個主要來源是墨西哥和美國西南部的銀膠菊灌木。橡膠墊、內(nèi)管及汽車的一些部件和卡車輪胎等部分是由回收的橡膠制成的。制成的所有SBR 的四分之三用于輪胎 — 世界上最多的橡膠制品。這些橡膠的熱穩(wěn)定性使它們適合于用在汽車水箱軟管。它們的防濕的作用使得它們很適用于戶外。乳膠甚至用于幫助固定沙漠土壤使它們易于農(nóng)用。從經(jīng)濟(jì)和環(huán)保角度出發(fā)，循環(huán)使用橡膠材料的最好方法是沉淀或煅燒。這些微生物可以氧化硫酸酯中的的硫，從而可能打破橡膠材料中的硫橋。但現(xiàn)在，發(fā)生了巨大的變化。 。 南華大學(xué)九九級化學(xué)工程與工藝專業(yè)畢業(yè)論文 第 26 頁 共 27 頁 橡膠工業(yè)在我國社會主義建設(shè)中起著重要的作用。橡膠碎屑的表面將會從彈性轉(zhuǎn)換成具有粘性的狀態(tài)。由此可見，人類需要通過有效的途徑來循環(huán)使用橡膠材料，從而使這些廢棄輪胎作為一種原材料具有新的價值。汽車和卡車的防碰緩沖器、吸收振動的內(nèi)件、以及防碎的燃料箱有利于防止高速路上的傷亡。 硅橡膠在 O 型圈和密封用途中表現(xiàn)的特別好。 異丁烯橡膠是由埃克松研究和工程公司在四十年代發(fā)展成商業(yè)產(chǎn)品的。 世界上合成的橡膠一半以上是由苯乙烯和丁二烯的單體制成的。碳酸鈣、粘土和二氧化鈦是非黑填料，可以降低成本和增加硬度，但是不影響產(chǎn)品的強(qiáng)度。巴西三葉膠提供了世界天然橡膠供應(yīng)量的 99％以上。 天然合成橡膠的柔軟性、彈性和耐用性使得它們成為精選的材料，用于緩沖震動、減弱突然的沖擊、衰減振動、傳遞能量以及其他很多方面。 南華大學(xué)九九級化學(xué)工程與工藝專業(yè)畢業(yè)論文 第 16 頁 共 27 頁 特別致謝： 在為期四個多月的畢業(yè)論文實驗及論文寫作過程中，我們 一直得到了學(xué)院的領(lǐng)導(dǎo)和老師非常重要的幫助及支持。一方面濃硫酸有很強(qiáng)的氧化性，易使產(chǎn)品的色澤變深；另一方面濃硫酸有很強(qiáng)的腐蝕性，排出的廢水易造成環(huán)境的污染。這主要是因為加熱時間過長，丙烯酸酯發(fā)生自聚的原因。 、催化劑的最佳用量試驗 試驗條件 ○ 1 丙烯酸的用量為 ； ○ 2 正丁醇的用量為 ； ○ 3 甲苯的用量為 15mL； ○ 4 對苯二酚的用量為 ； ○ 5 反應(yīng)溫度為 125℃左右； ○ 6 反應(yīng)時間約為 3h； ○ 7 對催化劑 FeCl3?6H20 用量進(jìn)行改變。并在此基礎(chǔ)上，確定最佳催化劑種類，做了確定最佳反應(yīng)溫度、反應(yīng)時間、反應(yīng)物配比、催化劑用量的試驗。帶水劑的用量要適宜，既能 迅速帶出反應(yīng)生成的水，又不至于因帶水劑過多而降低反應(yīng)液的濃度，導(dǎo)致反應(yīng)速率降低。 為了防止丙烯酸及其酯類發(fā)生聚合反應(yīng)，由于溫度是引發(fā)丙烯酸及其酯類聚合反應(yīng)的最常見的因素，溫度越高，越容易發(fā)生聚合反應(yīng)，聚合物產(chǎn)量越大。它們的活性稍低，反應(yīng)溫度一般較硫酸催化劑高，需要在 180～ 250℃下進(jìn)行。但由于醇脫水可生成烯烴及醚，酯化時的反應(yīng)溫度必須嚴(yán)格控制。 超強(qiáng)酸是在 20 世紀(jì) 70 年代發(fā)現(xiàn)的一類較硫酸強(qiáng)度大許多的酸。其改進(jìn)方安是將雜多酸負(fù)載在載體上，形成固載雜多酸，在完成酯化反應(yīng)后，可通過過濾直接回收。不過有關(guān)硫酸作酯化催化劑的研究至今仍有報道。目前采用的催化劑主要有一下幾種類型：無機(jī)酸 ﹑ 有機(jī)酸或其鹽 ﹑ 雜多酸及固載雜多酸 ﹑強(qiáng)酸性陽離子交換樹脂﹑固體超強(qiáng)酸﹑分子篩和非酸性催化劑。 、丙烯酸正丁酯合成反應(yīng)歷程及動力學(xué) 酸催化酯化是雙分子反應(yīng)歷程。改變這種現(xiàn)狀的