			Home About us Contact

Green Process (green + process)

Distribution by Scientific Domains

Polymers and Materials Science	40%
Chemistry	40%

Selected Abstracts

Copper(II) Triflate as a Source of Triflic Acid: Effective, Green Catalysis of Hydroalkoxylation Reactions

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
Mathieu J.-L.
Abstract The hydroalkoxylation of dicyclopentadiene (DCPD) and norbornene (NB) with 2-hydroxyethyl methacrylate (HEMA) for the synthesis of industrially relevant monomers has been investigated with various metal-based Lewis acids and strong Brønsted acids. In the absence of other additives, copper(II) triflate is the most efficient catalyst system. Kinetics, electron spin resonance (ESR), catalyst poisoning and cross experiments indicate that triflic acid (TfOH) is the true active catalyst in these reactions. This in situ generation of TfOH occurs via reduction of Cu(OTf)2 by the olefin reagent (DCPD, NB). The copper ions present in the reaction mixture act as radical polymerization retardants, preventing polymerization of HEMA (which is observed with most other metal salts and strong Brønsted acids investigated), thus improving the selectivity and yield (up to 95%) for the desired products. These observations have led to the development of a highly effective green process, using bulk reagents (no solvent) and a cheap, metal-free catalyst system, based on TfOH and a phenolic radical inhibitor (2,5-di- tert -butylhydroxytoluene, BHT). [source]

A green process for preparing silver nanoparticles using spinning disk reactor

AICHE JOURNAL, Issue 2 2008
Clifford Y. Tai
Abstract The main theme of this research was to synthesize nanoparticles using green materials in a spinning disk reactor (SDR), which is a type of Higee equipment. The reducing agent and protecting agent were glucose and starch, respectively, either of which is an inexpensive and nontoxic material. Silver particles were prepared by continuously pumping two solutions, which were a mixture of AgNO3 aqueous solution containing protecting agent and another mixture of NaOH aqueous solution containing the reducing agent, into the chamber of the SDR, where a liquid,liquid reaction took place. The reaction time was less than 10 min, which was much shorter than the traditional methods. After washing and redispersing, silver particles of 10 nm or smaller were obtained, and the redispersed aqueous suspensions were stable for more than 40 days with or without the addition of a dispersing agent. A high-gravity process that combines economic benefit with environmental benignancy was successfully developed to produce silver nanoparticles. © 2007 American Institute of Chemical Engineers AIChE J, 2008 [source]

Effects of Crosslinking Methods on Structure and Properties of Cellulose/PVA Hydrogels

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2008
Chunyu Chang
Abstract A series of hydrogels were prepared from cellulose and PVA in NaOH/urea aqueous solution using both physical and chemical crosslinking methods. The hydrogels were secure and biodegradable materials. Their structure and properties were characterized by FTIR spectroscopy, DSC, XRD and SEM. The results indicated that all of the cellulose/PVA hydrogels exhibited homogeneous porous structures and a certain miscibility. The swelling degree and water uptake of the chemical hydrogels were markedly higher than those of the physical hydrogel. This work demonstrates two novel methods to prepare cellulose/PVA hydrogels with different functional properties via a green process. [source]

Economical Advantages of Low-Pressure Plasma Polymerization Coating

PLASMA PROCESSES AND POLYMERS, Issue 6 2005
Hirotsugu Yasuda
Abstract Summary: Low-pressure plasma polymerization coating, as described in this paper, is an ultimately green process that uses a minimum amount of substances and produces a minimum amount of effluent and hence does not require an environmental remediation process. The super-green aspect of the processing entirely changes the equation for the viability of the process in industrial applications. The main hampering factors for the low-pressure processes are 1) psychological fear of vacuum processes, 2) relatively high initial equipment costs, and 3) a lack of adequate cost estimate for the entire process. In many cases, the first two factors are enough for planners to shy away from this promising technology. However, when one examines the overall cost of processing as a whole, the cost of initial equipment often is not the decisive factor. Such cases are presented in the nano-film coating applied in corrosion protection of aluminum alloys, steel, and surface-state modification of contact lenses. The benefits of environmental friendliness, non-hazardous processing and superior performance of products that can be achieved only by low-pressure plasma polymerization coatings are more than enough to compensate the initial cost of the equipment. For nanofilm (20 nm) coatings, the most expensive annual operation cost is for wastewater treatment, which is much more than the initial cost of vacuum plasma polymerization reactor. [source]

Environmental strategies and green product development: an overview on sustainability-driven companies

BUSINESS STRATEGY AND THE ENVIRONMENT, Issue 2 2009
Vito Albino
Abstract To respond effectively and efficiently to the environmental sustainability challenge, an important role can be played by companies, through appropriate strategies and operations, such as green processes and product development. In this paper, we investigate whether the development of green products is supported by the environmental strategic approaches adopted by sustainability-driven companies, and whether there are economic sector or geographical area specificities. To this purpose, first we develop a taxonomy of environmental strategies and we define measurable proxies for both the environmental strategic approaches identified and the green product development. Then, we study a sample represented by the companies included in the Dow Jones Sustainability World Index (DJSWI). The methodology used is based on the content analysis of companies' websites and relevant documents, such as environmental and sustainability reports. The main result is that the levels of adoption of different environmental strategic approaches are higher for green product developers than for green product non-developers. Moreover, the most implemented strategic approaches for green product developers vary depending on the economic sector, while a more homogeneous behaviour is found from the geographical perspective. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment. [source]