共查询到15条相似文献,搜索用时 78 毫秒
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综述了可降解塑料的研究开发现状及其进展。可降解塑料的降解时控性研究,合成、加工工艺改进以及降低成本的研究, 可控光-生物降解的全面降解性研究和一次性使用塑料(包括地膜、包装材料和餐具等) 实用性研究, 仍是今后需深入探讨的重要研究课题。文中强调, 该项技术开发的首要前提是制订降解塑料及其降解性的术语定义并建立其降解性的评价试验方法。 相似文献
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以羧酸共生稀土作为PVC塑料紫外光氧化降解的光敏剂,采用人工加速老化实验、户外曝晒实验等方法进行降解试验,并用红外光谱,紫外光谱和凝胶色谱等方法对含羟酸共生稀土光敏剂可降解PVC塑料的可降解性能进行了研究。初步探讨了羧酸共生稀土敏化PVC膜光氧化降解的作用机理。结果表明,羟酸共生稀土(如La、Ce、Pr等)对PVC分子的结构具有明显的光敏化降解作用,并具有抑制PVC在光照过程中发生交联的作用。 相似文献
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淀粉与丙烯酸甲酯的接枝共聚物作为生物降解塑料的研究 总被引:6,自引:0,他引:6
如何解决废弃塑料制品的再资源化和使用无污染的降解塑料是当今人类急待解决的热点课题.淀粉与丙烯酸甲酯(MA)进行接技共聚以制备塑料发泡产品的研究已有报道[‘-‘1,一般认为塑料中淀粉含量在40%以上的产品,很容易在土壤中被微生物降解掉[‘].这些研究都是在水溶液体系中进行的,本文的目的在于开发高淀粉含量的接校共聚物,为此对比了在3种不同体系(MA-CH3OHA12O三元均相溶液体系,水溶液体系和乳液体系)中得到的接校共聚物的力学性能、形态观察与组成情况,发现单纯追求高接技效率与接枝链MA的高分子量并不一定能得到… 相似文献
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Day M. Cooney J. D. Shaw K. Watts J. 《Journal of Thermal Analysis and Calorimetry》1998,52(2):261-274
The thermal characteristics of a series of degradable polymers have been investigated using thermogravimetry and differential
scanning calorimetry. While the results of the thermogravimetry experiments suggest that the thermal stability of the polymers
should not pose any problems at the temperatures that can be expected in a commercial composting process (60°C), phase changes
associated with some of the polymers investigated may cause problems in the interpretation of data from composting degradation
studies. Several biodegradable polymers were observed to have melt transitions at temperatures similar to those found in a
composting environment. Consequently, under the controlled composting conditions used to evaluate biodegradable polymers,
degradation of a polymer may be inferred, while actually the polymer has merely undergone a phase change.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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“白色污染”已成为目前普遍关注的一个全球性环保课题。将光催化剂掺入到塑料中制备出环境友好的可光降解复合塑料,利用其光催化活性可以使废弃塑料在太阳光的照射下发生有效降解,是解决“白色污染”问题的有效途径之一。本文综述了近年来固相光催化降解废弃塑料的研究进展,介绍了光催化剂TiO2、ZnO、α-FeOOH和H3PW12O40对废弃塑料的固相光催化降解效率及各种复合塑料的光催化降解机理,阐述了对光催化剂进行表面改性可以改善其在聚合物中的分散性,以及对光催化剂进行修饰可以提高其对可见光的吸收,从而提高复合塑料的固相光催化降解活性及对太阳光的有效利用率。最后,展望了固相光催化技术在废弃塑料处理领域的应用前景。 相似文献
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《Analytical letters》2012,45(14):1759-1775
Abstract The behaviour of plastics, namely, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyamide and some copolymers, was studied in a combustion chamber in which the conditions of large-scale fires were simulated. Volatile combustion products were frozen-out or analyzed directly on two columns, one packed with Porapak Q and the other capillary column coated with squalane or CP Sil 5 CB. Carbonyl compounds were determined as the 2,4-dinitro-phenyl hydrazones on an OV-101 stationary phase. Thermal conductivity and flame ionization detectors were used. The decomposition products were identified either on the basis of retention data (retention indices) or by combined capillary GC-MS. The data obtained are used for the cataloguing of plastics from the point of view of their product toxicity during fires. 相似文献
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Yvonne Shashoua 《Macromolecular Symposia》2006,238(1):67-77
Once plastics objects are registered in museum collections, the institution becomes responsible for their long term preservation, until the end of their useful lifetime. Plastics appear to deteriorate faster than other materials in museum collections and have a useful lifetime between 5 and 25 years. Preventive or inhibitive conservation involves controlling the environments in which objects are placed during storage and display, with the aim of slowing the major deterioration reactions. Once in progress, degradation of plastics cannot be stopped or reversed, so the aim of preventive conservation is to ‘buy time’ for the object. Inhibitive conservation of plastics involves the removal or reduction of factors causing or accelerating degradation including light, oxygen, acids, relative humidity and acidic breakdown products. Specific approaches to conservation have been developed for cellulose nitrate, cellulose acetate, PVC and polyurethanes by considering the most effective action to inhibit their major degradation pathways. The purpose of this article is to outline the main factors causing degradation of the least stable plastics in museum collections and present an overview of the conservation treatments established to date. Recent research has suggested that some of the conservation practices to slow the rate of deterioration in use today, particularly those for cellulose nitrate and acetate, are poorly effective and that alternatives should be evaluated. One alternative is low temperature storage. 相似文献
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