期末考试论文,环境友好材料——可降解材料.doc

;.环境友好材料可降解材料 信工学院电气信息I类096班 摘要：本文对环境友好材料可降解材料的概念进行了阐述，介绍了当前已经开始使用的可降解材料以及正处于研发以及理论探讨中的各种可降解环保材料。详细陈述了可降解环保材料的发展应用历史以及当前国内外可降解材料的发展应用情况、发展进程，对可降解材料生产研发系统及技术进行了总结，并在此基础上进行了预测与展望，陈述了对于可降解环保材料的研发、生产、应用的感想。关键字：环境友好材料 生物降解塑料 聚乳酸 淀粉塑料 光降解塑料1. 引言当前社会随着各行各业欣欣向荣的发展，对于环境的破坏也越来越严重。最重要的是人类不仅大量的掠夺式利用各种资源而且还把利用后产生的废弃物随意丢弃。随着环境问题的日益凸显，人们已经开始注意到随意丢弃废弃物对于环境的危害，而在这众多危害严重的废弃物中，塑料制品又是其中的主体。但是处理大量的废弃物使之变得对环境无害需要大量的人力物力，是一种消极的应对方式，面对日益严重的废弃物污染特别是塑料制品废弃物污染问题，人们开发出了一类新型环境友好型材料可降解材料。2.正文：2.1可降解材料的概念、分类：可降解材料包括自然降解材料和微生物降解材料。由微生物合成的生物降解塑料，简称生物塑料，包括生物聚酯、生物纤维素、多糖类和聚氨基酸等，是一类能完全被自然界中的微生物降解的塑料。 微生物体内贮存的动植物脂肪或糖原，是一类脂肪族聚酯，称为生物聚酯，是微生物的营养物质。当无碳源存在时，这些聚酯可分解为乙酰辅酶作为生命活动的能源。 聚乳酸（PLA）又称聚内交酯，是以微生物发酵产物乳酸为单体化学合成的。使用后可自动降解，不会污染环境。聚乳酸可以被加工成力学性能优异的纤维和薄膜，其强度大体与尼龙纤维和聚酯纤维相当。聚乳酸在生物体内可被水解成乳酸和乙酸，并经酶代谢为CO2和H2O，故可作为医用材料。日本、美国已经利用聚乳酸塑料加工成手术缝合线、人造骨、人造皮肤。聚乳酸还被用于生产包装容器、农用地膜 、纤维用运动服和被褥等。 2.11淀粉塑料 含淀粉在90%以上，添加的其他组份也是能完全降解的，目前已有日本住友商事公司、美国Wamer-Lamber公司、意大利Ferrizz公司等宣称研究成功含淀粉量在90%100%的全淀粉塑料，在(1月1年)完全生物降解而不留任何痕迹，无污染，可用于制造各种容器、瓶罐、薄膜和垃圾袋等。 全淀粉塑料的生产原理是使淀粉分子变构而无序化，形成了具有热塑性能的淀粉树脂，因此又称为热塑性淀粉塑料。其成型加工可沿用传统的塑料加工设备。 以淀粉为原料开发生物降解塑料的潜在优势在于：淀粉在各种环境中都具备完全的生物降解能力；塑料中的淀粉分子降解或灰化后，形成二氧化碳气体，不对土壤或空气产生毒害；采取适当的工艺使淀粉热塑性化后可达到用于制造塑料材料的机械性能；淀粉是可再生资源，取之不绝，开拓淀粉的利用有利于农村经济发展。 需要说明的是，我国目前生产的淀粉塑料绝大多数为填充型淀粉塑料，即在非生物降解的高分子材料中添加一定比例的淀粉,通过淀粉的生物降解而致使整个材料物理性能崩溃,促使大量端基暴露以致氧化降解,但这种“崩溃”后的剩余部分中的PE、PVC等均不可能降解而一直残留于土壤中，日积月累当然会造成污染，因此国外将此类产品归属为淘汰型。 2.12光降解塑料 光降解塑料是指在光的作用下能发生降解的塑料。 光降解塑料按制造方法可将光降解塑料分成合成型降解塑料和添加型降解塑料。2.121合成型光降解塑料a、 乙烯/一氧化碳共聚物（E/CO） 光降解以主链断裂为特征。 E/CO的光降解速度和程度与链所含的酮基的量有关，含量越高，降解速度越快，程度也越大。美国德克萨斯州的科学家曾对E/CO进行过户外曝晒实验，在阳光充足的六月，E/CO最快只需几天便可降解。 b、乙烯基类/乙烯基酮类共聚物（Ecolyte） Ecolyte分子侧链上的酮基在自然光的作用下可发生分解。 Ecolyte的光降解性能优于E/CO，但成本也较高。这类聚合物的缺点是一旦见光就开始发生降解，几乎没有诱导期，需要加入抗氧剂以达到调节诱导期的目的。 2.122添加型光降解塑料 添加型光降解塑料是在聚合物中添加少量光敏剂，在低浓度时是光氧化降解催化剂，经日光（紫外光）辐照而发生反应，使聚烯烃高分子断裂。 在PE、PP等聚合物中添加酮类、胺类等光敏剂都可取得较好的光降解性。 添加型光降解塑料成本低，生产工艺简单，做覆盖地膜使用效果较好。但其降解特性是曝光面降解比较彻底，埋在土壤里的部分则降解较差。这类光降解塑料的降解诱导期可控制在二个月以上。但降解时间可控性较差。2.2可降解材料的研发应用历史可降解材料到目前的发展将近20年，生物降解塑料，尤以淀粉添加的生物降解塑料近年来发展极为迅速。据Freedoia公司报告，美国降解塑料制品的销售量1987年23万吨，1989年为83万吨，预测1994年将增加到182.5万吨，2000年将达到300万吨；加拿大降解型塑料制品的销售量1989年为5万吨，1994年将增加到10万吨，2000年将达20万吨。另据美国Structure Analysis & Surveys调查，在欧洲和日本，降解塑料的发展将更快，预计到1995年，美国将失去此领域的支配地位，美国在世界降解塑料中的市场占有率从1990年的60%降至41%，而欧洲将从38%升到53%，日本从2%上升至6%。从降解塑料的种类分析，在北美地区，1989年，降解塑料总销售量88万吨，其中生物降解塑料为16万吨，预计1994年降解塑料为161万吨，光生物降解塑料47.5万吨其他降解塑料为11万吨。预测至2000年，降解塑料总需求达320万吨，其中生物降解塑料为110万吨，光降解塑料为105万吨，光降解塑料为90万吨，其他降解塑料为15万吨，1989年1994年，年平均增长率生物降解塑料为11.2%，光降解塑料为16%，光生物降解塑料为21.3%。19942000年，年平均增长率生物降解塑料为7.1%，光降解塑料为9.6%，光生物降解塑料为11.2%，其他降解塑料为5.3%。据此预测光生物降解塑料增长将是最快的。从降解塑料应用领域分析，北美1989年降解塑料总销售量的88万吨中，最大量的是用于包装，达76万吨，包括包装等袋类56万吨（其中垃圾袋47.5万吨，购物零售袋等8.5万吨）饮料罐提环10.5万吨，其他包装9.5万吨。其他有无纺布（卫生用）5.5万吨，农业用2.5万吨，其他领域4万吨。预计至1994年降解塑料在包装方面用量将达161万吨，无纺布为14.5万吨，农业用为7万吨，其他10万吨。预测至2000年，包装用量达248万吨，无纺布为30万吨，农业用16万吨，其他26万吨。19891994年，包装用年平均增长率为16.2%，无纺布为21.4%，农业用22.9%，其他领域为20.1%。19942000年年平均增长率，在包装方面为7.5%，无纺布为12.9%，农业用14.8%，其他领域17.3%。我国光降解塑料的研究开发始于70年代，80年代末开始对淀粉填充型生物降解塑料进行研究。90年代国家把“可降解塑料地膜”列入“八五”、“九五”重点科技攻关项目。社会上随着环境意识的日益增强，环境呼声日烈，从中央到地方，大专院校、科研单位、企业等上百家单位进入了降解塑料研究开发的行列，多次掀起了降解塑料热。目前发展现状可归纳为以下几个方面。 1、目前，我国研究开发的降解塑料品种以原料分类主要有聚乙烯、聚丙烯、聚苯乙烯等，从降解环境分类有光降解、光/生物降解、光/氧/生物降解、光/碳酸钙降解、淀粉填充型生物降解以及高填充碳酸钙环境友好材料等的母料或专用料。其中光/生物聚乙烯降解塑料地膜、环境降解塑料地膜列入了国家“八五”、“九五”重点科技攻关计划；完全生物降解塑料列入了国家863计划。从总体而言，除完全生物降解塑料外，我国降解塑料研究开发进程与世界同步，技术水平与国外先进水平接近或相当。 2、据不完全统计，我国已建成的双螺杆降解塑料母料生产线上百条，年产能力约10万t，已有部分企业正式投产或批量生产，但开工率较低。制品的生产线及能力则难以统计，因为一部分是同属一母料生产厂，约占母料生产线的20%，一部分是新建生产线，但相当一部分是现有塑料加工企业利用原有成型加工设备，外购母料，根据市场需要生产的。 目前降解塑料市场尚未形成，主要以销定产，因此产量也很难统计，估计母料年产量约几千吨，制品产量2-3万t。 3、据初步统计，我国目前从事降解塑料研究、生产和应用的单位已超过100家，分布在教育、化工、轻工、石油、机械、水电、农业、环保、环卫、粮食、金融、军工等部门的产、学、研单位及乡镇企业、民营企业、合资企业、独资企业等。降解塑料母料生产能力分布悬殊，沿海城市居多，西南、西北地区较少。 4、目前开拓的应用领域主要有农用、包装和日用一次性消费品。开发的产品有地膜、肥料袋、堆肥袋、水果网套、包装膜、食品袋、购物袋、杂品袋、垃圾袋、快餐餐具、饮料杯、台布、手套、高尔夫球座等。目前降解地膜处于示范应用阶段，包装材料和日用杂品正在有序地推向市场。 5、1996年国家颁布了中华人民共和国固体废弃物处理法，其中明确规定塑料地膜及一次性包装塑料制品应当采用易回收利用、易处置或在环境中易消纳的产品。到目前为止，全国已有20多个省市先后出台了禁用或限用普通聚苯乙烯塑料发泡餐具和普通聚乙烯包装袋，规定或推荐采用纸板餐具、纸浆模塑餐具、光/生物降解聚丙烯餐具和光/生物聚苯乙烯发泡餐具以及降解聚乙烯塑料包装袋，既有利于环保，又满足交通、旅游、快餐业以及人们生活的需求。 6、近两年来，不少单位排除一切干扰，深入钻研，苦心经营，取得了不少的进展。比较突出的企业有：天津丹海股份有限公司、深圳绿维塑料有限公司、南京苏石降解树脂化工有限公司、海南天人降解塑料制品有限公司、北京市塑料研究所、上海申悦降解塑料有限公司等。 7、目前我国降解塑料试验评价方法和标准正在研究制定中。由国家经贸委、科技部提出并归口，由铁道部劳卫所负责起草的“一次性可降解餐具通用技术条件”的国家标准，日前已通过了专家审查讨论，已报送国家质量技术监督局审批中。降解塑料研究会已完成“降解塑料识别标志”、“降解聚乙烯包装薄膜”及“降解聚苯乙烯发泡片材及餐具”的行业标准，前两项已经全国塑料制品标准化委员会批准，预计不日即将发布，后者正待审批中。另降解塑料研究会协同中国农科院土肥所、原化工部广州合成材料研究院、中科院上海有机所、上海三林降解树脂有限公司对深圳德实利、天津丹海、南京苏石、吉林金鹰、河北雄崎、厦门燕源、惠州环美、浙江华江等的降解聚乙烯包装薄膜、降解聚苯乙烯泡沫餐盒与普通塑料膜、盒进行了为期1年的土壤填埋、垃圾堆埋试验检测，积累了许多有益的数据和经验，目前正在汇集整理检测数据，并结合试验室检测数据进行分析评价，试图探索研究出适于我国国情的试验评价方法和标准。今天，可降解材料已经被越来越多的家庭、企业、国家所认识，应用发展前景也越来越宽广。可降解材料的研发与应用也正在飞速的向前发展，可以想象的到，在不久的明天，在外面的日常生活之中将不会再有白色污染出现，不会再有遍地令人头痛的各种各样的垃圾。外面只要把不能再回收利用的废弃物堆放在一起，让它们被降解掉就可以了，省时省力又经济。那时，外面的社会、外面的地球将变得更美好、更干净，人类社会将于大自然更好的和平共处，共同迎接更美好的未来。参考文献：聚乳酸的发展及研究现状，吴苏琴|李艳霞|龚磊|黄长干江西化工2006-12可完全生物降解材料的应用进展，吕方|朱光明|刘代军塑料科技2007-07 English TitleName:wang zhenjun Student Number:6100209251 Class:Electricity a 096 classAbstract: this paper environmentally friendly materials - degradable materials of the paper expatiated on the concept, this paper introduces the current have begun to use of biodegradable materials and is in r&d and theoretical discussion of various biodegradable environmental protection material. Specify the biodegradable environmental protection material the development and application of history and the current domestic and international degradable materials development application, development process, on degradable materials r&d and production system and technology is summarized, and on this basis is forecasted and prospect for biodegradable stated environmental protection material research, development, production and application of feeling.Key Words：Environmental friendly materials Biodegradable plasticsPolylactide Starch plastics light degradable plasticsPerface:The current social with all walks of life, for the development of prosperous environment destruction also more and more serious. The most important is not only a lot of human LveDuoShi use of various resources but also by using the waste generated after discarded. Along with the environmental issues highlighted increasingly, people have started noticing discarded waste for environmental hazards in this great harm serious waste, plastics is one of the main body. But with the amount of waste harmless to the environment make it needs a large number of manpower and material resources is a kind of negative coping styles, facing the increasingly serious waste pollution especially plastic waste pollution problem, people developed a new class of environment-friendly materials - degradable materials.Text:2.1 degradable materials of the concept, classification:Degradable materials include natural biodegradable materials and microbial degradation materials. By microbial synthetic biodegradable plastics, abbreviation biological plastic, including biological polyester, biological cellulose, polysaccharides and poly (amino acid etc, is a kind of nature can completely by microbial degradation of plastics. Microbial body storage of plants and animals fats or glycogen, is a kind of aliphatic polyester, called the biological polyester, is microbial nutrition. When no carbon sources exist, these polyester can be divided into acetyl coa as life activities of energy. Polylactic acid (PLA) is also called together within the ester, based on microorganism fermentation product lactic acid monomer chemical synthesis. After use, can be automatically degradation, will not pollute the environment. Polylactic acid can be processed into mechanics performance fibers and film, its strength roughly with nylon fibers and polyester fiber quite. Polylactic acid in vivo can be hydrolyzed to lactic acid and acetic acid, and the metabolic enzymes to CO2 and H2O, it can be as medical material. Japan, the United States has been using polylactic acid plastics processing into surgical suture lines, artificial bone, artificial skin. Polylactic acid was used in the production of packaging containers, agricultural film and fiber with sportswear and sheets, etc. 2.11 Starch Plastics containing starch above 90%, add other components is also can complete biodegradation, at present had the Japanese sumitomo corporation Co., us Wamer - Lamber company, Italy declared Ferrizz companies, such as the amount of research has successfully starchy 90% to 100% of the whole starch plastics in (January 1 year) complete biodegradation and leave no traces, no pollution, can be used in the manufacture of all kinds of containers, bottles, film and garbage bags, etc. Whole starch plastics production principle is to make starch molecular allostent and disorderly change, has formed a thermoplastic resin, so the starch can also called thermoplastic starch plastics. Its forming process can adhere to the traditional plastic processing equipment. With starch as the raw material development biodegradable plastics potential advantage lies in: starch in various environments has complete biodegradable ability; Plastic the starch biodegradation or ash molecular a.v., form carbon dioxide gas, no soil or air produce harm; Take proper craft make starch thermoplastic a.v. can achieve used in the manufacture of plastic of material mechanical properties, Starch is renewable resources, tap, develops the starch using favour rural economic development. Need explanation is, our countrys current production of starch plastics most for filling type, namely in the starch plastics biological catabolic polymer materials adding a certain proportion of starch, through the starch biodegradation and cause the whole material physical properties of the base to collapse, exposure that oxidation degradation, but this collapse after the rest of the PE, PVC etc are impossible to the soil degradation and remain all in, accumulate over a long period of course can cause pollution, the foreign ownership for such products will be eliminated type. 2.12Light DegradablePlastics Light degradable plastics refers to the light under the action of degraded plastics can occur. Light degradable plastics by the way of making can be divided into light degradable plastics fits the molding degradable plastics and add type degradable plastics. 2.121 Close MoldingLight Degradable Plastics Ethylene/carbon monoxide copolymer (E/CO) photodegradation in the chain rupture as feature. E/CO light degradation speed and degree with chains contain of ketone base is related to the content, the higher the degradation, the faster the greater. The U.S. state of Texass scientists have to E/CO had outdoors insolate experiment, in the sunny in June, E/CO fastest only a few days, biodegradable. B, vinyl class/vinyl copolymer (ketone Ecolyte) Ecolyte molecular side chain of ketone base in natural light can occur under the action of decomposition. Ecolyte light degradation performance than the E/CO, but the cost is higher also. This kind of polymer drawback is once see light began degraded, almost no induction period, needed to add antioxidizing agents in order to achieve the purpose of regulating induction period. 2.122 Add Type PhotodegradationPlastic additives type light degradable plastics in polymer is adding a small amount of photosensitizer, in low concentration is light oxidation degradation by ultraviolet sunlight (catalyst, and happen) irradiation reaction, make polyolefin polymer fracture. In PE, PP etc in polymer add ketone, amine such photosensitizer all can acquire better photodegradation sex. Add type light degradable plastics low cost, simple production technology, do cover plastic use effect is good. But its degradation characteristics was exposed face degradation more thorough, buried in soil degradation part is poorer. This kind of light degradable plastics degradation induced period can be controlled in two months. But degradation time controllable poorer. 2.2Degradable MaterialsDevelopmentAnd Application Of History Degradable materials to the current development of nearly 20 years, biodegradable plastics, especially in starch added biodegradable plastics in recent years very quickly. According to Freedoia companies report, American degradable plastics products sales 1987 230,000 tons, 1989 to 83 million tons, predict 1994 will increase to 182.5 tons, 2000 will reach 300 million tons; Canada degradation type plastic products sales in 1989 for 5 million tons, 1994 will increase to 100,000 tons, 2000 of 20 tons. Another according to the order and Surveys investigation, practices in Europe and Japan, degradable plastics development faster, it is expected to 1995, the United States will lose the field dominance, the United States on the world market share of degradable plastics from 1990 60% drop to 41%, and Europe will be from 38% ascend to 53%, Japan from 2 percent to 6%. From the analysis, types of degradable plastics in North America, 1989, degradable plastics total sales 88 million tons, including biodegradable plastics for 16 million tons, is expected to 1994 degradable plastics for 161 million tons, light - biodegradable plastics 4.75 million tons of other degradable plastics for 11 million tons. Forecast to 2000, degradable plastics aggregate demand reach 3.2 million tons, including biodegradable plastics for 110 million tons, light degradable plastics 105 million tons, light - degradable plastics for 90 million tons, the other is 15 tons degradable plastics, 1989-1994, the average annual rate of biodegradable plastics klatskin, light degradable plastics for 16%, light - biodegradable plastics for 21.3%. 1994 to 2000, at an average annual rate of biodegradable plastics 7.1 per cent, light degradable plastics at 9.6%, light - biodegradable plastics klatskin, other degradable plastics 5.3%. A forecast that light - biodegradable plastics growth will is the fastest. From degradable plastics application domain analysis, North America in 1989 degradable plastics total sales of 88 million tons, the amount is for packaging, amounted to 76 million tons, including packaging bags of 560,000 tons (including bags 4.75 million tons, retail shopping bag etc 8.5 million tons) igniting 10.5 million tons, other lift ring packaging 9.5 million tons. Other non-woven (health) 5.5 million tons, with agricultural use 2.5 million tons, the other fields, 40,000 tons. Expected to 1994 degradable plastics in packaging dosage will reach 161 million tons, non-woven fabrics of 1.45 million tons, agricultural use for 70,000 tons, other 10 million tons. Forecast to 2000, packaging dosage of 248 million tons, non-woven fabrics for 30 tons, agricultural use 16 million tons, other 26 million tons. 1989-1994, wrapping average annual growth rate for 16.2%, non-woven for 21.4%, agricultural use 22.9%, other areas for 20.1%. 1994-2000 annual average annual growth rate in packaging for 7.5%, non-woven fabrics for agricultural use, at 14.8% 12.9% and other fields 17.3%. China light degradable plastics of research and development in the 1970s, began in the late 1980s began on starch filling type biodegradable plastics were studied. The 1990s national biodegradable plastic film into five-year and the ninth five-year key torch-plan projects. Society with growing awareness of the environment, the environment, fierce, the calls from central to local levels, colleges and universities and scientific research institutions and enterprises in hundreds of unit entered degradable plastics research and development ranks, repeatedly raised degradable plastics hot. The present development situation can be classified into the following respects. 1, at present, our research and development of degradable plastics breed with raw material classification are mainly polyethylene, polypropylene and polystyrene and so on, from degradation environmental degradation, classification have light light/biodegradable, light/oxygen/biodegradable, light/calcium carbonate degradation, starch biodegradation and filling type high filling calcium carbonate environmentally friendly materials female material or special material. One light/biological polyethylene degradable plastics film and environmental degradation plastic film on the national five-year and the ninth five-year key scientific research plan, Complete biodegradable plastics included in the national 863 plan. Generally speaking, besides completely biodegradable plastics outside, our country degradable plastics research and development process and the world simultaneously, the technical level and the advanced world level close to or equivalent. 2, according to not complete count, our country already built twin-screw degradable plastics mother material production line, annual output of hundreds of ability about 100,000 t, there has been some enterprises officially put into production or batch production, but lower starts. Products of the production line and ability is difficult to statistics, because part is belong to a mother material manufacturer, accounts for about 20% of the material production line, female part is newly established production line, but quite part is the existing plastics processing enterprise USES the original forming equipment, outsourcing home liu, according to the markets needs production. Currently degradable plastics market has not been formed, main manufacturing-according-to-sale, therefore yield is difficult to estimate mother material statistics, annual production capacity of thousands of tons, products output 2-3 million t. 3, according to preliminary statistics, China is currently engaged degradable plastics research, production and application of unit has more than 100, distribution in education, chemical industry, light industry, petroleum, machinery, water and electricity, agri