Recovery of Polymer Waste by Shear Strains
Recycling, Modification and Recovery of Natural and Synthetic Polymer Waste by Shear and Shock-Shear Strains
Tech Area / Field
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
- ENV-SPC/Solid Waste Pollution and Control/Environment
- MAT-ELE/Organic and Electronics Materials/Materials
8 Project completed
Senior Project Manager
Mitina L M
VNIIEF, Russia, N. Novgorod reg., Sarov
- Siberian Branch of RAS / Institute of Solid State Chemistry and Mechanochemistry, Russia, Novosibirsk reg., Novosibirsk\nRussian Academy of Sciences / Semenov Institute of Chemical Physics, Russia, Moscow
- University of Windsor, Canada, ON, Windsor
Project summaryA significant level of environmental contamination by wastes involving natural and synthetic polymers, exhaustion of natural resources, including oil and gas, make the problem of recovery and complete efficient application of industrial and domestic polymer waste one of the most topical in the world. Since natural and synthetic polymer waste is an extreme environmental hazard, environmentally safe and technologically efficient polymer recycling should be developed.The waste of natural and synthetic materials is an enormous reserve of technologically promising industrial stock, which is used rather inefficiently. Using mechanochemical processes for physicochemical modification of polymers is a way to solve the problem of recovery and efficient use of polymer waste.
The prime objective of the Project is to create solid-phase methods for wasteless and environmentally safe recycling and modification of natural and synthetic polymer waste are based on high-intensity shear strain.
The scientific and practical importance of this work is that it allows one to develop the scientific fundamentals of solid-phase recycling and modification of natural and synthetic polymer waste under the action of high-intensity shear strain and to obtain new data on regularities inherent to solid-phase transformations of polysaccharides and polymers of the polyolefin series under shear strain, to establish principles of solid-phase dechlorination provided by mechanical activation and self-propagating synthesis (SPS) process; to develop solid-phase process of alkali cellulose production and solid-phase process of chitin deacytilation. This approach helps in solution of the problems of recovery and efficient use of industrial and domestic polymer waste. Moreover, it represents an environmentally safe way to use enormous waste for producing high-quality materials.
Solid-phase technologies will be developed and technical proposals will be prepared in the frame of the Project on ecologically pure wasteless large-tonnage recovery of: solid organochlorine compounds; wood to produce chemical-mechanical wood pulps and alkali cellulose; wood waste (sawdust) to produce new environmentally safe composite materials; shells of crustaceous to produce chitosan with the efficiency tenfold compared to the existing plants; polymer wastes involving polyethylene and polypropylene to produce new powder materials for composites with high dynamic characteristics.
Technological Approach and Methodology
The joint effect of high pressure and shear strain provided by extruder-reactors and shock-shear strain provided by planetary ball mills is a promising method to disperse and modify natural and synthetic polymers. Chemical reactions taking place under conditions of high pressure and shear strain are studied in a number of works. The results obtained are summarized in the paper of N.S. Enikolopyan, Dokl. Acad. Nauk SSSR, 1985, vol. 283, ¹ 4, p. 897. The regularities of solids dispersion and changes in their physicochemical properties under a shock-shear strain are discussed in a monograph: E.G. Avvakumov, Mechanical Methods for Activating Chemical Processes, Novosibirsk: Nauka, 1986. These processes are characterized by following distinctive features: very efficient mixing and dispersion of reagents to molecular sizes, although both starting materials represent powder, under these conditions various chemical processes occur with a very low activation energy.
The main results on dispersion and modification of natural and synthetic polymers obtained by the authors of the Project are summarized in the following papers: E.V. Prut, Polymer Science, 1994, v. 36, ¹ 4, pp. 601-607; S.Z. Rogovina, T.A. Akopova, Polymer Science, 1994, v. 36, ¹ 4, pp. 593-600; E.V. Prut, A.N. Zelenetski, Usp. Khim., 2001, v. 70, ¹ 1, pp. 72-83; S.Z. Rogovina, in “ Chitin and Chitosan: Production, Properties, Application”, K.D. Skryabin, Ed., 2002, Moscow: Nauka, pp.64-78., K.G. Korolev, A.I. Golovanov, N.N. Maltsev, O.I. Lomovski, V.L. Salenko, V.V. Boldyrev, Chemistry in the Conditions of Steady Evolution, 2003, in press.The results obtained show that high-intensity shear strain can be a basis for wasteless and efficient large-tonnage technologies to be used in recycling of natural and synthetic polymer waste. Implementation of studies planned under the Project suggests several interconnected lines of investigation involving the total cycle of recycling and recovery of natural and synthetic polymers. The main objectives of the Project, Institutions-Executors are presented: studying principles of solid-phase recycling and modifying wood and wood waste under high-intensity shear strain; developing solid phase process of recycling shells of crustaceous involving chitin to produce chitosan; studying principles of solid-phase recycling and modifying polymer waste involving polyolefins; developing principles of processing multicomponent powder mixtures based on polymers modified to composite materials, studying mechanical properties of composite materials;developing technical proposals on industrial using of solid-phase processes to recycle and recover the waste of natural and synthetic polymers
Advanced methods of studying physicochemical properties of polymers, in particular, differential scanning calorimetry, high-resolution electron microscopy, X-ray diffraction analysis, X-ray phase analysis and chromatography, FTIR spectroscopy, and various methods of mechanical and thermophysical testing will be used in the frame of the Project.
The employees of RENC-VNIIEF, IChPh of RAS and ISBChMCh of RAS are skilled in using high-intensity shear and shock strains for dispersing and modifying natural and synthetic polymers, in studying their properties, and producing composite materials based on the forementioned polymers. The preliminary results of polymer recycling, modification and producing highly remunerative materials are indicative of high efficiency of these approaches, a good combination of technical potentialities, scientific and practical experience of specialists, that should allow one to solve the problems presented in the Project.
International Collaboration. The Project is aimed at solving the topic problems that can favor business relations with foreign partners. The participation of foreign collaborators will provide the improvement in both the Project conception and accomplishment of Project goals. The exchange of material samples, joint seminars and publications, participation of collaborators in check-up of the activities under the Project and partnership in realization of the results obtained are suggested. All lines of the activities can be specified in joint programs.