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Polymer Chemistry
Abstract
In the oilfield a wide variety of polymers and polymeric chemistry are used to provide chemical solutions to a wide variety of issues. This chapter explores a number of types of polymer and their derivatives. The petroleum industry uses and consumes a vast array of oligomer/polymer products, many of which are used in chemical additives and as polymers in solution. The other main type of polymer used is a solid‐state polymer, such as engineering materials. The chapter gives a brief overview of their use and environmental acceptability and impact. It examines the various mechanisms of polymer degradation and focuses on how such degradation pathways, again especially biodegradation pathways, affect the environmental fate of the polymer additive. In achieving a more sustainable approach to the extraction and exploitation of oil and gas resources, it is necessary to consider that the reuse and recycling of all materials and polymers are no exception.
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Achieving successful zonal isolation is critical to install smart completion tools. Currently, cementing and mechanical packers are the only conventional methods used in Saudi fields to provide zonal isolation. However, these techniques are difficult to operate and result in reduced inner casing string diameter. Another method to provide zonal isolation for smart completion tools and to complete them in single stage is to use a rubber elastomer bonded onto a base pipe. The rubber swells in oil and provides a seal between the base pipe and the open hole. This paper will outline the step-by-step qualification testing that was carried out by Saudi Aramco facilities in an attempt to improve zonal isolation for smart completions. In this study, we present lab evaluation of elastomers at 190°F using six different oil samples. The evaluation involved studying the effect of oil viscosity and API gravity. Also, the study investigated the effect of acids on the swelled elastomers. To the best of the authors' knowledge no previous work was done to investigate the impact of these factors on the swelling mechanisms. The elastomer bonded in pipes was tested in autoclaves. The pressure drop across the pipes was measured as a function of time. The effects of other factors were investigated using elastomer samples and fluid characterization. The oil swelling elastomers withstood pressure up to 5,000 psi at 190°F after placing the elastomers in some crude oils. In addition, the elastomers swelled rapidly in some oils and slowly in others.
The present invention generally relates to emulsifiers for oil-based drilling fluids and muds comprising an emulsifier based on the polyamides derived from fatty acid/carboxylic acid and optionally alkoxylated polyamines. The invention also relates to oil or synthetic based drilling fluids comprising the emulsifiers of the invention and to drilling methods utilizing same.
New fluids are disclosed for use in servicing subterranean formations containing oil and gas. In particular, an improved chemical gelling additive for hydrocarbon based fracturing fluids is disclosed having reduce, negligible or no volatile phosphorus at temperatures below about 250° C.
As the main component of lignocelluloses materials, cellulose is a biopolymer consisting of many glucose
units connected through β-1,4-glycosidic bonds. The breakage of the β-1,4-glycosidic bonds by acids
leads to the hydrolysis of cellulose polymers, resulting in the sugar molecule glucose or oligosaccharides.
Mineral acids, such as HCl and H2SO4, have been used in the hydrolysis of cellulose. The lignocellulosic
materials usually require a first step of pretreatment due to the association between the three major
components of plant cell wall (cellulose and hemicelluloses fractions and lignin) in order to make available
the monomeric sugars found in these fractions, for fermentation to ethanol. Different procedures have
been employed, for example, acid hydrolysis, alkali hydrolysis, steam explosion, among others. The
pretreatment using dilute sulfuric acid (acid hydrolysis) is the most widely used for having high efficiency in
the separating process of cell wall components resulting in hemicellulose hydrolysate and cellulignin. A
second step for obtaining the cellulose present in the cellulignin, studies have shown a need for
delignification stage using sodium hydroxide as catalyst. The cellulose is submitted to acid or enzymatic
hydrolysis to solubilize the glucose (cellulose hydrolyzate). Regardless of intense research on cellulose
hydrolysis process by enzymatic way, the amount of hydrolyzate obtained in this process is still less than
the amount required for subsequent studies on the fermentation of these hydrolysates which opens the
option of research for the use of chemical hydrolysis. In order to use sugarcane bagasse as a substrate for
ethanol production, optimum conditions for acid hydrolysis of cellulose fraction were investigated. A 23 full
factorial Central Composite Design (CCD), including three replications at the center point was applied to
evaluate the effect of temperature, acid concentration and reaction time on extraction efficiency. In this
study, the hydrolysis of cellulose conditions varied in terms of sulfuric acid (H2SO4) concentration (2-6 %,
w/v), reaction time (10-30 min) and incubation temperature (155-175 ºC). The experiments were carried
out using a 200-ml stainless-steel container (19 x 7 cm), which was tightly sealed and immersed in a
silicone bath provided with electrical heating. The maximum extraction efficiency (E) was 71 % under the
conditions of 2 % of H2SO4 at 155 ºC for 10 min, which the main components (in g L-1) in the hydrolysate
were glucose, 22.74; 5-hydroxymethylfurfural, 0.206; furfural, 0.145 and no xylose, arabinose and acetic
acid formation was detected. Experiments will be performed to evaluate the fermentability of this
hydrolysate to ethanol by Scheffersomyces stipitis.
Quite possibly the first comprehensive text on galactomannans, Industrial Galactomannan Polysaccharides compiles information on their industrial uses in the form of gums including locust bean, guar, tara, fenugreek, cassia-tara, and Sesbania-bisipinasa varieties. The book describes how galactomannans are currently produced commercially and how they have become industrial commodities. It provides a simple and clear introduction to these vital substances, it compares their various sources. Highlights General chapters on carbohydrates, hydrocolloids and associated rheology, interactions of galactomannans, and derivatization of polysaccharides A brief history of each product gum, cultivation of the plant sources, seed, habitat, chemical structure, functional properties, manufacturing processes, and applications. Special focus on the most representative galactomannans: guar and locust bean gums An in-depth compilation of industrial galactomannans information, this book is designed for the manufacturers, traders, and end users of galactomannans, as well as technologists in polysaccharides-related industries and scientists and academics interested in carbohydrates.
A food (ingredient) is regarded as functional if it is satisfactorily demonstrated to affect beneficially 1 or more target functions in the body beyond adequate nutritional effects. The term inulin-type fructans covers all β(2←1) linear fructans including native inulin (DP 2–60, DPav = 12), oligofructose (DP 2–8, DPav = 4), and inulin HP (DP 10–60, DPav = 25) as well as Synergy 1, a specific combination of oligofructose and inulin HP. Inulin-type fructans resist digestion and function as dietary fiber improving bowel habits. But, unlike most dietary fibers, their colonic fermentation is selective, thus causing significant changes in the composition of the gut microflora with increased and reduced numbers of potentially health-promoting bacteria and potentially harmful species, respectively. Both oligofructose and inulin act in this way and thus are prebiotic: they also induce changes in the colonic epithelium and in miscellaneous colonic functions. In particular, the claim “inulin-type fructans enhance calcium and magnesium absorption” is scientifically substantiated, and the most active product is oligofructose-enriched inulin (Synergy 1). A series of studies furthermore demonstrate that inulin-type fructans modulate the secretion of gastrointestinal peptides involved in appetite regulation as well as lipid metabolism. Moreover, a large number of animal studies and preliminary human data show that inulin-type fructans reduce the risk of colon carcinogenesis and improve the management of inflammatory bowel diseases. Inulin-type fructans are thus functional food ingredients that are eligible for enhanced function claims, but, as more human data become available, risk reduction claims will become scientifically substantiated.
In the recent years, significant advances have been made in the development of biodegradable polymeric materials for various applications. Sustainability, industrial ecology, eco-efficiency and green chemistry are guiding the development of the next generation of materials, products and processes. In particular, biodegradable polymer materials (known as biocomposites) are of interest. They have use in packaging, agriculture, medicine and other are as in India. Polymers form the back bones of plastic materials and are continually being employed in an expanding range of areas. These polymers bring a significant contribution to the sustainable development in view of the wider range of disposal options with minor environmental impact. As a result, the market of these environment friendly materials is in rapid expansion, almost exceeding 10-20% per year.
The inspiration for this monograph derived from the realization that human technical capacity has become so great that we can, even without malice, substantially modify and damage the gigantic and remote outer limit of our planet, the stratosphere. Above the atmosphere of our ordinary experience, the stratosphere is a tenuous layer of gas, blocked from rapid exchange with the troposphere, some twenty kilometers above the surface of the earth, seldom reached by humans, and yet a fragile shell which shields life on earth from a band of solar radiation of demonstrable injurious potential. It is immediately obvious that if stratospheric ozone were reduced and consequently the intensity of solar ultraviolet radiation reaching the earth's surface were increased, then human skin cancer, known to be related to solar ultraviolet exposure, would also be increased. But how does one even begin to estimate the impact of changed solar ultraviolet radiation on such a diverse. interacting, and complex ecosystem as the oceans? Studies which I conducted in Iceland focused on this question and were noted to the Marine Sciences Panel of the Scientific Affairs Committee of NATO by Professor Unnsteinn Stefansson, leading to a request to investigate the possibility of organizing a NATO sponsored Advanced Research Institute on this topic.
Drag reduction is observed as reduced frictional pressure losses under turbulent flow conditions and hence, substantially increases the flowrate of the fluid. Practical application includes water flooding system, pipeline transport and drainage system. Drag reduction agent, such as polymers, can be introduced to increase the flowrate of water flowing, reducing the water accumulation in the system and subsequently lesser possibility of heavy flooding. Currently used polymer as drag reduction agents is carboxymethylcellulose, to name one. This is a synthetic polymer which will seep into the ground and further harm our environment in excessive use of accumulation. A more environmentally-friendly drag reduction agent, such as the polymer derived from natural sources or biopolymer, is then required for such purpose. As opposed to the synthetic polymers, the potential of biopolymers as drag reduction agents, especially those derived from a local plant source, are not extensively explored. The drag reduction of a polymer produced from a local plant source within the turbulent regime will be explored and assessed in this study using a rheometer where a reduced a torque produced can be perceived as a reduction of drag. This technique of assessment for drag reduction ability is also unique as many literatures on drag reduction rely heavily on flow loop data which sometimes, require time and high cost for the fabrication of the flow loop. The new method proposed is less time consuming and is more practical which is producing carboxymethylcellulose from the banana peel. The cellulose powder was converted to carboxymethylcellulose (CMC) by etherification process using sodium monochloroacetate and sodium hydroxide. The carboxymethylation reaction then was optimized against the reaction temperature. Then, the biopolymers will be rheologically characterized where the viscoelastic effects and the normal stresses produced by these biopolymers will be utilized to further relate and explain the drag reduction phenomena. The research is structured to focus on producing the biopolymer and also assess the drag reduction ability of the biopolymer produced. Various temperatures when synthesizing the biopolymers will be studied as a drag reduction agent to obtain the optimum value of which the biopolymer works the best. The rheological behavior of the biopolymers will also be analyzed and relate to the drag reduction ability. The results are intended to expand the currently extremely limited experimental database for biopolymers in turbulent flow.
A method for the dewatering of sludges in industrial waste waters utilizing a hydrophobically-modified coagulant copolymer of diallyldimethyl ammonium chloride and quaternized dimethylaminoethyl acrylate or quaternized dimethylaminoethylmethacrylate and a flocculant.
Hydraulic fracturing is used extensively to develop oil and gas wells in both high and low-permeability formations. Biopolymer-based fluids, including guar or guar derivatives, constitute the majority of polymers in fracturing fluids. These polymers cause formation damage, which is a serious problem on production enhancement. Therefore, the search for an alternative to guar is meaningful to the oil industry. In this paper, a novel viscosifier (V1) was developed to prepare fracturing fluids.
The rheological properties and proppant suspending ability of V1-based fluid have been studied with the effects of viscosifier concentration, temperature, and salts. Formation damage of the new type of hydraulic fracturing fluid in sandstone has been evaluated and compared to guar, hydroxypropyl guar (HPG), and viscoelastic surfactant (VES) fluids. The effects of temperature, viscosifier type, concentration, and formation permeability were investigated. The regained permeability of sandstone cores (expressed as a percentage of the initial permeability) was used to quantify the damage degree in coreflood tests.
The viscosity measurements have shown that V1-based fluids were stable up to 350°F with a high tolerance to KCl and CaCl2. Moreover, V1-based fluids had a good proppant suspending ability at 75 and 250°F, which out-performanced guar-based fluids. Coreflood tests were run using Berea and Bandera sandstone cores. As for V1 fluids, the regained permeabilities of the cores were 88% or higher of the initial permeabilities, suggesting that V1 caused a slight damage. However, guar and HPG fluids caused much more damage than V1 fluids under same conditions. The effects of temperature, viscosifier concentration, and formation type were different for guar-based fluids from V1 fluids. The external filter cake was formed when the V1 fluid was injected; however, no external filter cake was found for guar, HPG, or VES. The filter cake could be removed by injecting 5 wt% KCl brine in the opposite direction.
It was the first time to use this new cellulosic viscosifier in hydraulic fracturing fluids. The new type of fracturing fluid has better thermal stability and proppant suspending ability than guar-based fluids under the same conditions. Moreover, high regained permeability of sandstone cores can be maintained when treated by the new fracturing fluid.
Among the world's natural sources of energy, petroleum stands out as the largest contributing mineral. This makes it the most sought-after mineral. Methods for oil recovery are constantly studied, and innovations are being made to improve the recovery of oil. Chemical Enhanced oil recovery (EOR) process is therefore at the fore-front of these studies and innovations.
The research work presents a comparative study of the core flooding carried out with different Alkali/Surfactant/Polymer (ASP) slugs formulated using sodium hydroxide (NaOH) an alkaline, surfactant being Lauryl Sulphate and Shell Enordet and polymer- gum Arabic and Xanthan gum.
The result shows that the ASP slug of Xanthan gum with Shell Enordet 0242 and Lauryl Sulphate had the highest displacement efficiency of 71.23% and 49.51% respectively. The others ASP slug formulated with gum Arabic and Shell Enordet or Lauryl Sulphate gave an efficiency of 31.36% and 32.20% respectively.
For heavy Oil recovery, the use of Shell Enordet 0242 or Lauryl Sulphate and Xanthan gum or gum Arabic will improve recovery. However, Xanthan gum gave a more stable displacement front than gum Arabic. Therefore, a higher concentration of gum Arabic is recommended for better recovery.
The authors investigated corrosion resistance of polypropylene coating newly developed for pipelines operating at elevated temperatures and obtained the following results. 1) The polypropylene coating has an excellent indentation resistance, a larger impact strength and peel strength compared with the polyethylene coating even at 100°C. 2) The polypropylene coating with special antioxidants has an excellent resistance to thermal oxidation, and the life time of about 25 years at 100°C is estimated. 3) The polypropylene coating with the excellent resistance to thermal oxidation has a property to prevent residual internal stress cracking due to defects in the coating in the temperature range from 23°C to 100°C, even though the coating on steel pipe has a larger residual stress compared with the polyethylene coating. It is considered from the results mentioned that the newly developed polypropylene coated steel pipe has an excellent durability at 100°C.
The development of polypropylene extrusion coatings for the external corrosion protection of steel pipes for high temperature service is described. The improvement of impact strength at low temperature and long-term durability at high temperature was studied. The properties of the developed polypropylene coating for high temperature line pipe were compared with those of polyethylene and fusion bonded epoxy coatings.
Novel fiber-forming biopolymers are now being manufactured using large-scale fermentation equipment. One such material is the bacterial storage compound polyhydroxybutyrate (PHB) which has good thermoplastic properties and can be melt spun into fibers. Other polymers that are drawing interest include polysaccharides, chitin, alginate, dextran and hyaluronic acid as well as proteins. Wide use of these materials is yet to be realized due to high manufacturing cost.
The construction industry had changed considerably in recent years influencing production rate, construction techniques and total quantity of materials used each year. This paper deals with materials requirement planning based on network schedule, inventory control systems for materials and spares at stores/sites, and consumption control through reconciliation of materials.
This paper describes the current development and acquired experiences obtained in a produced water re-injection (PWRI) project in high WOR mature oilfields located in the Amazon rainforest in Peru.
Pluspetrol operates Block 8 and Block 1-AB, both located in the Northern part of Marañon foreland basin in Peruvian jungle. Twenty-four oilfields had been discovered between 1971 and 1980 and they have been producing since 1978. Currently 174 wells are producing from 17 fields with average water cut as high as 95%.
Productive reservoirs are composed of fluvial, estuarine and shallow marine sandstones from Vivian and Chonta formations of Cretaceous age. Main reservoirs have lateral continuity with porosity between 12 and 24% and permeability between 50 md and 5000 md.
The production mechanisms are bottom and edge water drive. It is observed that water cut in these reservoirs shows a very sharp increase to values above 90% in early stages of exploitation due to mobility differences between viscous oil and formation water.
In a first stage a series of injectivity test were performed in both shallow and deep reservoirs. These tests showed a better injectivity in deep reservoirs like Vivian and Pozo.
At the beginning injection rates were under matrix conditions but later with the aid of thermal effect and high injection rates, injection under fracturing conditions was achieved allowing us to increase injectivity index and thus reducing the number of required water disposal wells.
This chapter deals with formation of hydrates in offshore system and different hydrate blockages, hydrate formation case studies, risk management in hydrate plug prevention. The main goal of this chapter is to educate about where and how hydrates form, to facilitate flow assurance or plug prevention, as well as safe dissociation when plugs do form. It also provides a background for the protection, avoidance, and remediation. Various case studies and figures are illustrated to show hydrate formation pressures and temperatures as a function of methanol concentration in free water for a given gas mixture. The chapter also covers risk management in hydrate plug prevention. The key principle of cold stabilized flow in each process is to change all free water droplets completely to hydrate as quickly as possible. © 2011 Dendy Sloan, Carolyn Ann Koh, Amadeu K. Sum, Norman D. McMullen, George Shoup, Adam L. Ballard, and Thierry Palermo. Published by Elsevier Inc. All rights reserved.
The majority of commodity plastics and materials are derived from petroleum-based chemicals, illustrating the strong dependence on products derived from non-renewable energy sources. As the most accessible, renewable form of carbon (in comparison to CO2), lignocellulosic biomass (defined as organic matter available on a renewable basis) has been acknowledged as the most logical carbon-based feedstock for a variety of materials such as biofuels and chemicals. This Review focuses on methods developed to synthesize polymers derived from lignin, monolignols, and lignin-derived chemicals. Major topics include the structure and processing of lignocellulosic biomass to lignin, polymers utilizing lignin as a macromonomer, synthesis of monomers and polymers from monolignols, and polymers from lignin-derived chemicals, such as vanillin.
The biodegradation process of three chitosan samples characterised by similar values of deacetylation degree but different molecular weights in an aqueous medium has been studied. The biodegradation process was caused by microorganisms present in activated sludge from the waste-water treatment station of a cellulose plant. The range of the most appropriate temperatures for chitosan biodegradation was estimated as 30-36°C. The shortest time of biodegradation and the induction time was observed in the chitosan sample with the lowest molecular weight. In this article, the changes to biodegraded chitosan structure as estimated by FTIR spectrophotometry, GPC chromatography and x-ray (WAXS) methods are presented.
Oilfield chemical demand has risen 4.3 percent annually through 2011. Gains will be driven by a rise in rig counts, more use of well stimulation and enhanced oil recovery (EOR) methods and more deepwater drilling and production. Working Guide to Oil Field Chemicals is a guide to the benefits and trade-offs of numerous oil field chemicals used in the petroleum and natural gas industry today. Oil field chemicals are gaining increasing importance, as the resources of crude oil are decreasing. An increasing demand of more sophisticated methods in the exploitation of the natural resources emerges for this reason. Working Guide to Oil Field Chemicals reviews the progress in the area of oil field chemicals and additives of the last decade from a rather chemical view. The material presented is a compilation from the literature by screening critically approximately 20,000 references. The book is ordered according to applications, just in the way how the jobs are emerging in practice. It starts with drilling, goes to productions and ends with oil spill. Several chemicals are used in multiple disciplines, and to those separate chapters are devoted. Two index registers are available, an index of chemical substances and a general index. Condensed for readability this manual provides users with information on oil field chemicals such as drilling muds, Corrosion Inhibitors Gelling Agents, Scale Inhibitors and Bacteria Control. Each chapter follows the same template. In the introductory comments of each chapter a brief introduction to the chemical or polymer type is given and earlier monographs and reviews dealing with the topic are listed for quick reference. The text continues with monomers, polymerization and fabrication techniques and discusses aspects of application. After this, suppliers and commercial grades are collected, as well as safety aspects. Chemicals are ordered by use including drilling muds, corrosion inhibitors, and bacteria control Includes cutting edge chemicals and polymers such as water soluble polymers and viscosity control Handy index of chemical substances as well as a general chemical index.
Exhaustive studies on the degradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes. Under ambient conditions, polymers are known to undergo degradation, which results in the deterioration of polymer properties, characterized by change in its molecular weight and other physical properties. In this paper mainly the biodegradation of synthetic polymers such as polyethers, polyesters, polycaprolactones, polylactides, polylactic acid, polyurethane, PVA, nylon, polycarbonate, polyimide, polyacrylamide, polyamide, PTFE and ABS have been reviewed. Pseudomonas species degrade polyethers, polyesters, PVA, polyimides and PUR effectively. No microorganism has been found to degrade polyethylene without additives such as starch. None of the biodegradable techniques has become mature enough to become a technology yet.
Lignin is an aromatic polymer forming up to 30% of woody plant tissues, providing rigidity and resistance to biological attack. Because it is insoluble, chemically complex, and lacking in hydrolysable linkages, lignin is a difficult substrate for enzymatic depolymerization. Certain fungi, mostly basidiomycetes, are the only organisms able to extensively biodegrade it; white-rot fungi can completely mineralize lignin, whereas brown-rot fungi merely modify lignin while removing the carbohydrates in wood. Several oxidative acid reductive extracellular enzymes (lignin peroxidase, manganese peroxidase, laccase, and cellobiose:quinone oxidoreductase) have been isolated from ligninolytic fungi; the role of these enzymes in lignin biodegradation is being intensively studied. Enzymatic combustion, a process wherein enzymes generate reactive intermediates, but do not directly control the reactions leading to lignin breakdown, has been proposed as the mechanism of lignin biodegradation. The economic consequences of lignin biodegradation include wood decay and the biogeochemical cycling of woody biomass. Efforts are being made to harness the delignifying abilities of white-rot fungi to aid wood and straw pulping and pulp bleaching. These fungi can also be used to degrade a variety of pollutants in wastewaters and soils, to increase the digestibility of lignocellulosics, and possibly to bioconvert lignins to higher value products.
A novel method of generating a polymer gel at a specified location in a subsurface formation was developed by adding superparamagnetic nanoparticles to the gel-forming polymer and heating the polymer by the nanoparticle-based hyperthermia. It blocks only the high permeability zones by highly localized gelling of the polymer employing magnetic hyperthermia heating, so that the oil in the low permeability zone can be recovered. In this paper, the gelling behavior of hydrolyzed polyacrylamide-polyethylenimine (HPAM-PEI), curdlan, methyl cellulose (MC) and hydroxypropyl methylcellulose (HPMC) was studied as a function of temperature and salinity. The effect of adding iron-oxide superparamagnetic nanoparticles (Fe3O4-NP) on gellation was also studied. The elastic and viscous moduli (G′ and G”) of curdlan suspension, and MC and HPMC solutions (with and without Fe3O4-NP) were measured which served as a quantitative measure of the gelling temperature and the gel state. For the curdlan, MC and HPMC boipolymers, the gel formation efficiency is enhanced by the presence of salts, but the presence of Fe3O4-NP does not have significant effect on gel formation.
Synthetic Polyacrylamide based polymers and polysaccharides such as guar gum, xanthan gum carboxymethylcellulose and starch have been used for long. The Polyacrylamides are easily amenable to shear degradation although they are very efficient drag reducing and flocculating agents even at low ppm concentrations. On the other hand polysaccharides are fairly shear stable but are not very efficient drag reducers and flocculants. Their aqueous solution are also subjected to rapid biodegradation. It was contemplated that in the case where Polyacrylamide chains are grafted on polysaccharide backbones, efficient shear and biodegradation drag reducing and flocculating agents may be developed.
We report here a novel anti-biodegradable hydrophobic acrylamide copolymer that was prepared from acrylamide, acrylic acid, sodium 3-(allyloxy)-2-hydroxypropane-1-sulfonate and N-allyl-2-(2,4-dichlorophenoxy) acetamide using the 2,2′-azobis(2-methylpropionamide) dihydrochloride initiation system. Subsequently, the copolymer was characterized by FT-IR, 1H NMR, TG-DTG and water-solubility. And the biodegradability test indicated that the copolymer was not deemed to be readily biodegradable via a closed bottle test established by the Organization for Economic Co-operation and Development (OECD 301 D). Meanwhile the copolymer could significantly enhance the viscosity of the aqueous solution in comparison with partially hydrolyzed polyacrylamide. A viscosity retention of 51.9% indicated the result of a dramatic improvement of temperature tolerance. And then the excellent salt resistance, shear resistance, viscoelasticity, long-term stability of the copolymer could be obtained, which provides a good theoretical foundation for the application in enhanced oil recovery. In addition, this copolymer exerted stronger mobility control ability with a resistance factor of 22.1 and a residual resistance factor of 5.0, and superior ability for enhanced oil recovery of 12.9%. Hence, the copolymer has potential application for enhanced oil recovery in high-temperature and high-salinity reservoirs.
Recently the price of crude oil and various petroleum fractions has been increased by about 20 times, beyond all expectations. The availability of oil and other petroleum fractions has also become very uncertain. The shortage of oil has led to the severe competition between fuel for energy and feedstock for petrochemicals. Although the entire petrochemicals including fertilizers and synthetic polymers consume less than 10% of the supply of crude oil, the demand for fuel for energy makes the prospect of assured supply of feedstock for petrochemicals at a reasonable price increasingly gloomier. The cost advantage of polymer material in general over other coventional materials such as metals and alloys, glass and ceramics etc. has already been eroded considerably by the price raise of curde oil. Never before have plastics been faced with such a tough competition from conventional materials. Oil as a feedstock is also not renewable and one day, sooner or later, it will dry out.
Compostable Polymer Materials deals with an environmentally important family of polymers. These compostable polymers are specially designed to be disposed of in industrial and municipal compost facilities after their useful lives. They are able to undergo degradation and leave no visible, distinguishable or toxic residue. Environmental concerns and legislative measures taken in different regions of the world make compositing an increasingly attractive route for the disposal of redundant polymers.
The demand for biodegradable chemicals is increasing as chemical producers and consumers anticipate more stringent standards for degradability in new and existing products. Poly(aspartic acid) (PAA) is an example of a chemical that shows promise as a biodegradable replacement for polyacrylic acid, a nonbiodegradable polymer that is used in a wide variety of products and applications. In order to meet the potential demand for PAA, we have developed processes for commercial production. These processes utilize solid-phase condensation polymerization of aspartic acid to polysuccinimide in a commercial reactor. The polysuccinimide is then base hydrolyzed to PAA. The performance of PAA made by these methods is comparable and in some cases superior to that of polyacrylic acid in many mineral scale inhibition and particulate dispersion tests. Biodegradation studies of PAA show that it is significantly biodegradable. Preliminary toxicity studies of PAA indicate that it is nontoxic and environmentally compatible.