共查询到20条相似文献,搜索用时 109 毫秒
1.
Zoran S. Petrović Yijin Xu Jelena Milić Gregory Glenn Artur Klamczynski 《Journal of Polymers and the Environment》2010,18(2):94-97
Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration
were prepared. Soft segment concentration was varied from, 40 to 70 wt%. Biodegradation was studied by respirometry. Segmented
polyurethanes with soft segments based on polyricinoleic acid degrade relatively slow losing about 11% carbon after 30 days,
but faster than corresponding petrochemical polyesterurethanes. Since biodegradation proceeds mainly through the soft segments,
higher soft segment content polymers displayed slightly higher biodegradation. Polyurethanes with dispersed hard domains in
the soft phase displayed slightly faster biodegradation than those with co-continuous morphology. Polyester diol degrades
slower than castor oil but significantly faster than the polyurethanes with built in soft segments from the same diol. Castor
oil biodegrades slower than soybean oil. 相似文献
2.
Wei Seng Ng Choy Sin Lee Sit-Foon Cheng Cheng Hock Chuah Shew Fung Wong 《Journal of Polymers and the Environment》2018,26(7):2881-2900
Biodegradable polyester polyol was synthesized from oleochemical glycerol monostearate (GMS) and glutaric acid under a non-catalyzed and solvent-free polycondensation method. The chemical structure of GMS-derived polyester polyol (GPP) was elucidated by FTIR, 1H and 13C NMR, and molecular weight of GPP was characterized by GPC. The synthesized GPP with acid value of 3.03 mg KOH/g sample, hydroxyl value of 115.72 mg KOH/g sample and Mn of 1345 g/mol was incorporated with polyethylene glycol (PEG) and polycaprolactone diol (PCL diol) to produce a water-blown porous polyurethane system via one-shot foaming method. The polyurethanes were optimized by evaluating glycerol as a crosslinker, silicone surfactant and water blowing agent on tensile properties of polyurethanes. All polyurethanes underwent structural change, and crystalline hard segments of polyurethanes were shifted to higher temperature suggested that hard segments undergone re-ordering process during enzymatic treatment. In terms of biocompatibility, polyurethane scaffold produced by reacting 100% w/w of GPP with isophorone diisocyanate and additives showed the highest cells viability of 3T3 mouse fibroblast (94%, day 1), and MG63 human osteosarcoma (107%, day 1) and better cell adhesion as compared to reference polyurethane produced by only PEG and PCL diol (3T3 cell viability: 8%; MG63 cell viability: 2%). The current work demonstrated GPP synthesized from renewable and environmental friendly resources produced polyurethanes that allows improvement in physico-chemical, mechanical and biocompatibility properties. By blending with increasing content of GPP, the water-blown porous polyurethane scaffold has shown great potential as biomaterial for soft and hard tissue engineering. 相似文献
3.
Responding to environmental, sustainability, business, and market factors, DuPont has commercialized a new polymer platform, Sorona®, based on 1,3-propanediol. The physical and chemical property advantages over other polymers are described. The diol component of this polymer, 1,3-propanediol, has been demonstrated to be manufacturable via biological (fermentation) process from corn sugar. The economic, environmental, and process/product quality advantages of bio-PDO over conventional diols are discussed. 相似文献
4.
Elżbieta Beran Sylwia Hull Mieczysław Steininger 《Journal of Polymers and the Environment》2013,21(1):172-180
The relationship between the chemical structure of poly(alkylene glycol)s (PAGs) and their biodegradability was studied using a set of polymeric fluids that included poly(ethylene glycol), poly(propylene glycol) (PPG), random copolymers of ethylene oxide (EO) and propylene oxide (PO) differing in the EO/PO ratio as well as PAGs capped with ether or acyl moieties. The PAGs that were tested had an average molecular weight (MW) in the range of 350–3,600 Da and differed in their polymer backbones by either linear (diol type) or branched (triol type) molecules. The ultimate biodegradability of the PAGs was determined according to ISO 14593 (CO2 headspace test) with a non-pre-exposed (as in OECD 310 test) and pre-exposed (adapted) inoculum. PAGs with the structure of PPG and copolymers of EO/PO of diol or triol structures with average molecular weights lower than 1,000 Da can be considered as readily biodegradable. Their ultimate biodegradation exceeds the limit of 60 % (according to the criteria of the OECD 310 test). PAGs with a copolymer structure and MW values ranging between 1,000 and 3,600 Da are not readily biodegradable, but they can be considered as those of inherent ultimate biodegradability. The increased EO content in PAG structures and the acylation of the terminal hydroxyl groups with carboxylic acids favourably influenced their biodegradability. Capped PAGs containing terminal ether groups appeared to be resistant to biodegradation. 相似文献
5.
Gity Mir Mohamad Sadeghi Ramin Shamsi Mahsa Sayaf 《Journal of Polymers and the Environment》2011,19(2):522-534
Chemical recycling of PET has been developed by various methods. Aminolysis is one of chemical recycling methods of PET has
been developed recently. The obtained product using aminolysis, Bis (2-hydroxy ethylene) terephthalamide (BHETA), has the
potential for further reactions to obtain useful products. There are few reports on usage of recycled BHETA from PET waste
to synthesis of polyurethanes. On the other hand, various biodegradable polyurethanes have been synthesized using polycaprolactone
diol. Therefore, caprolactone is a new potential in synthesis of biodegradable polyurethanes from PET waste. In this work,
novel biodegradable polyurethanes have been synthesized using BHETA. In this order, at first polyols with different molecular
weights have been synthesized through ring opening polymerization of caprolactone by BHETA, then urethane linkages were formed
using HDI (Hexamethylene Diisocyanate) without chain extender. Chemical, thermal, mechanical and dynamic mechanical properties,
biodegradability, morphology and UV resistance of synthesized polyurethanes have been investigated. 相似文献
6.
Seeds of red pepper and tomato were sowed and cultivated in a soil blended with powdery poly(l-lactide) (PLLA), and poly(butylene succinate) (PBS). PBS depressed the growth of the two plants significantly even at a concentration as low as 5%, whereas PLLA up to 35% affected negligibly or even boosted the growth of the two plants. pH and number of microbial cells in the soil after 80 days of cultivation were almost the same independently whether the soil was blended with the two polymers or not. In contrast, the molecular weight of PBS decreased much faster than that of PLLA. Because succinic acid and 1,4-butane diol, from which PBS was synthesized, exhibited toxicity to both plant and animal cells to retard the germination rate of young radish seeds and to deform the morphology of HeLa cells significantly [1], the monomers and the oligomers produced from the PBS degradation should have a detrimental influence on the growth of the two plants. 相似文献
7.
Joanna Brzeska Aleksandra Heimowska Henryk Janeczek Marek Kowalczuk Maria Rutkowska 《Journal of Polymers and the Environment》2014,22(2):176-182
The aliphatic polyurethanes based on atactic poly[(R,S)-3-hydroxybutyrate] (a-PHB) and commercial oligomerols: poly(ε-caprolactone)diol and polyoxytetramethylenediol were investigated. a-PHB was obtained by anionic ring-opening polymerization of (R,S)-β-butyrolactone. The 4,4′-methylenedicyclohexyl diisocyanate and 1,4-butanediol were used as contributors of hard segments. The aim of the study was to determine the influence of synthetic, atactic a-PHB in soft segments of polyurethanes on their degradability in simulated body fluids (SBF) and Ringer solution. The incubation of polymer samples in both degradative solutions was carried out for 36 weeks. It was concluded that the presence of a-PHB in polyurethane structure accelerated their degradation in SBF and in Ringer solution and, protected the calcification process. 相似文献
8.
Manawwer Alam S. M. Ashraf Alok R. Ray Sharif Ahmad 《Journal of Polymers and the Environment》2010,18(3):208-215
Polyetheramide(PEtA) resin was synthesized by the condensation polymerization of N,N-bis(2-hydroxy ethyl) linseed oil fatty
amide diol (HELA) with resorcinol. It was further treated with different percentage of toluylene 2-4-diisocyanate (TDI) to
obtain the urethane modified polyetheramide resins (UPEtA). The structural elucidation of PEtA and urethane modified polyetheramide(UPEtA)
were carried out by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. These analyses confirm the formation of PEtA and UPEtA. Physico-chemical and physico-mechanical
analysis were performed by standard laboratory methods. The resin composition UPEtA-24 showed best physico-mechanical properties
with scratch hardness 2.0 kg, impact resistance 150 lb/in. and good bending ability. The thermal stability and curing behavior
of polymers were respectively studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal
analysis shows that these coatings can be used safely upto 190 °C. The coatings of UPEtA resins were prepared on mild steel
strips. The anticorrosive behavior of UPEtA coatings were investigated in acid, alkali, water and xylene. All the coatings
exhibit good chemical resistance performance in acid, alkali, saline and organic solvents, while the resin UPEtA-24 shows
the best performance. 相似文献
9.
The resourceful employment of vegetable oil based polymers in coating applications that yield novel properties, faces challenges usually in their processing. We have developed polyesteramide coatings from linseed (Linnum ussitatissium seeds) oil with improved coating properties. Linseed oil was first converted into N, N-bis 2-hydroxy ethyl linseed oil fatty amide diol (HELA). The resin was synthesized by the reaction of HELA with ethylenediaminetetraacetic acid (EDTA) to develop ethylenediamine polyesteramide (Ed-PEA). The latter was further treated with poly (styrene co-maleic anhydride) (SMA) in different (35–50) phr (part per hundred part of resin) to obtain ambient cured polyesteramide (AC-PEA). The structural elucidation of polymeric resin (AC-PEA) was carried out by FT-IR, 1H-NMR, and 13C-NMR spectroscopic techniques. Thermal behavior of AC-PEA was studied by thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC). The coatings of AC-PEA were prepared on mild steel strips to investigate their physico-mechanical and anticorrosive behavior (in acid, alkali, water and xylene). It was found that among all the samples, the one having 45 phr of SMA showed the best physico-mechanical and corrosion resistance performance. The thermal stability performance suggests that AC-PEA45 system could be safely used up to 150 °C. 相似文献
10.
Model oligo esters of terephthalic acid with 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol have been investigated with regard to their biodegradability in different biological environments. Well-characterized oligomers with weight-average molar masses of from 600 to 2600 g/mol exhibit biodegradation in aqueous systems, soil, and compost at 60°C. SEC investigations showed a fast biological degradation of the oligomer fraction consisting of 1 or 2 repeating units, independent of the diol component used for polycondensation, while polyester oligomers with degrees of polymerization higher than 2 were stable against microbial attack at room temperature in a time frame of 2 months. At 60°C in a compost environment chemical hydrolysis also degrades chains longer than two repeating units, resulting in enhanced degradability of the oligomers. Metabolization of the monomers and the dimers as well by the microorganisms could be confirmed by comparing SEC measurements and carbon balances in a Sturm test experiment. Based on these results degradation characteristics of potential oligomer intermediates resulting from a primary chain scission from copolyesters consisting of aromatic and aliphatic dicarbonic acids can be predicted depending on their composition. These results will have an evident influence on the evaluation of the biodegradability of commercially interesting copolyesters and lead to new ways of tailor-made designing of new biodegradable materials as well. 相似文献
11.
A series of formulations were prepared with different percentages of oligomer, epoxy diacrylate (EA-1020 ), monomer, 1,6 Hexane diol diacrylate,(HDDA) and different percentages of filler (Magnesium tri-silicate, Mg2Si3O8). Irgacure 369 [2-Benzyl-2-dimethyl-amine-1 (4-morpholinophenyl) butanone-1] was used in the formulations as photoinitiator. Ultraviolet (UV) cured thin polymer films were prepared from these formulating solutions on clean glass plates. Pendulum hardness (PH), gel content and macro scratch hardness (MSH) of the UV cured films were studied. One percent Mg2Si3O8 containing formulation showed the premium properties. The substrates (plain board) were coated by these formulating solutions and cured under the same UV lamp at different intensities of radiation. Various properties of the coated surface such as PH, gloss, adhesion, abrasion and MSH were investigated. The base coat containing 1% Mg2Si3O8 and top coat containing 48% HDDA produced the best performance among all the formulations inspected. The degradable properties in different weathering conditions on PH, gloss, adhesion, abrasion and MSH were measured. The surface cured with the optimized formulation (E) again yielded the minimum loss of the properties. 相似文献
12.
Shadpour Mallakpour Fatemeh Zeraatpisheh Mohammad R. Sabzalian 《Journal of Polymers and the Environment》2012,20(1):117-123
In this paper we studied the synthesis of biodegradable optically active poly(ester-imide)s containing different amino acid
residues in the main chain. These pseudo-poly(amino acid)s were synthesized by polycondensation of N,N′-(pyromellitoyl)-bis-l-tyrosine dimethyl ester as a diphenolic monomer and two chiral trimellitic anhydride-derived diacid monomers containing s-valine and l-methionine. The direct polycondensation reaction of these diacids with aromatic diol was carried out in a system of tosyl
chloride (TsCl), pyridine (Py) and N,N′-dimethylformamide (DMF) as a condensing agent. The structures and morphology of these polymers were studied by FT-IR, 1H-NMR, powder X-ray diffraction, field emission scanning electron microscopy (FE-SEM), specific rotation, elemental and thermogravimetric
analysis (TGA) techniques. TGA profiles indicate that the resulting PEIs have a good thermal stability. Morphology probes
showed these polymers were noncrystalline and nanostructured polymers. The monomers and prepared polymers were buried under
the soil to study the sensitivity of the monomers and the obtained polymers to microbial degradation. The high microbial population
and prominent dehydrogenase activity in the soil containing polymers showed that the synthesized polymers are biologically
active and microbiologically biodegradable. Wheat seedling growth in the soil buried with synthetic polymers not only confirmed
non-toxicity of polymers but also showed possibility of phyto-remediation in polymer-contaminated soils. 相似文献
13.
Ranau R Kleeberg KK Schlegelmilch M Streese J Stegmann R Steinhart H 《Waste management (New York, N.Y.)》2005,25(9):908-916
In order to determine the efficiency of different treatment systems for the reduction of odorous emissions, a gas chromatographic method followed by simultaneous mass spectrometry and olfactometry (GC-MS/O) was developed. Samples from a coffee bean roasting and a fat and oil processing plant were analyzed, respectively. The results were compared with the data obtained by olfactometric measurements. At a coffee bean roasting plant, cooling gases were analyzed prior to and after treatment in a full scale bioscrubber. The GC-MS/O analysis showed that the amounts of aldehydes and ketones decreased after treatment of cooling gases of coffee bean roasting in the bioscrubber, whereas the contents of the heterocyclic compounds, like pyridine and the pyrazines, and acetophenone and guaiacol remained almost unchanged. The amounts of dimethyl disulfide, 3-hydroxy-2-butanone, and the carboxylic acids increased after bioscrubber treatment. Furthermore, the performance of each stage of a combined experimental plant for the treatment of exhaust air of fat and oil processing was investigated. This treatment plant consisted of a bioscrubber, a biofilter, and an activated carbon adsorber. The important odor-active compounds of the exhaust air of fat and oil processing were the typical fat oxidation products (aldehydes, ketones) and with lower importance 2-pentylfuran, a few terpenes and aromates. Again, the key odor-active compounds, aldehydes and ketones, were degraded in the bioscrubber. Further degradation of aliphatic, unsaturated, methylated, and cyclic alkanes, as well as aromates, terpenes, and furans by the biofilter was observed. After the last treatment stage, the activated carbon filter, only small amounts of aliphatic, unsaturated, methylated, and cyclic alkanes and aromates remained in the waste gas. For both applications, the results of the developed GC-MS/O method correlated very well with olfactometric measurements. 相似文献
14.
The operations of carbonization facilities for municipal solid waste treatment in Japan were examined. Input waste, system processes, material flows, quality of char and its utilization, fuel and chemical consumption, control of facility emissions, and trouble areas in facility operation were investigated and analyzed. Although carbonization is a technically available thermochemical conversion method for municipal solid waste treatment, problems of energy efficiency and char utilization must be solved for carbonization to be competitive. Possible solutions include (1) optimizing the composition of input waste, treatment scale, organization of unit processes, operational methods, and quality and yield of char on the basis of analysis and feedback of long-term operating data of present operating facilities and (2) securing stable char demands by linking with local industries such as thermal electric power companies, iron manufacturing plants, and cement production plants. 相似文献
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资源循环科学与工程专业硕士毕业生存在规模小、科技创新能力不足、能力施展受限等问题,无法满足产业对高层次人才的需求。究其原因有:(1)新兴专业,其研究生导师队伍建设不健全,人才培养质量参差不齐;(2)交叉专业,其科技创新能力培养方向尚需融合凝练;(3)综合专业,其现有科研平台还不足以支撑学科发展,科技创新能力培养模式还没有完全形成。因此,本学科研究生培养单位应树立协同创新理念,坚持行业需求导向,充分挖掘办学特色和优势,凝练培养方向、完善以科技创新能力培养核心的研究生培养方案;加强师资队伍建设,建立健全科研平台;支持鼓励科技创新实践活动,做好学科前沿追踪;加强校校交流互动,提升硕士点认可度。 相似文献
17.
Joanna Burger Michael Gochfeld Charles W. Powers David Kosson Michael Greenberg Barbara Ley Toffler 《补救:环境净化治理成本、技术与工艺杂志》2009,19(2):99-122
Many federal, state, and private agencies deal with long‐term environmental problems within a transition framework where political administrations, funds, regulators, regulatory requirements, environmental conditions, and tribal and stakeholder concerns change. In this article, we examine the types of transitions, as well as important stabilities, that agencies face, the interactions with stakeholders that are vulnerable to disruption or failure, and some of the problems that develop as a result of these conditions, using the U.S. Department of Energy (US DOE's) Office of Environmental Management (EM) as a case study. Transitions, or instabilities, include changes in administrations at the federal, state, and local level; public perceptions and concerns; political climate; available funds; environmental conditions (e.g., global climate change, global contaminant transport, local and regional contamination); international and national business conditions; and site conditions (physical, chemical, biological). Governmental agencies operate under several different kinds of uncertainties, including scientific, fiscal‐year economic, technological, and societal. Not all information can be known, and the outcomes from scientific issues or technologies cannot always be predicted. The authors believe that transitions from one set of conditions to another can be more effectively integrated with the long‐term stability of environmental laws and regulations, and with the stability of the treaty rights and concerns of tribal nations, as well as the shorter‐term stability of career personnel and established programs. A sense of stability for government agencies allowing maintenance of ongoing environmental management programs can also be achieved through processes and programs, such as establishing long‐term contracts (for remediation or restoration work), schedule and scope documents, future land‐use documents, National Environmental Research Parks (which obligate lands to study and conservation), and other programs that set the direction of work and activities for many years. Further, two other factors are essential for success within any agency facing transitions: (1) expectations should be both forward‐looking and realistic, and (2) there must be flexibility in both programs and processes. The authors conclude that several features are essential to addressing some of the problems created by transitions, including information, integration, iteration, interaction, and inclusion. © 2009 Wiley Periodicals, Inc. 相似文献
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Amr S. Meawad Darinka Y. Bojinova Yoncho G. Pelovski 《Waste management (New York, N.Y.)》2010,30(12):2548-2559
Thermal power plants (TPPs) that burn fossil fuels emit several pollutants linked to the environmental problems of acid rain, urban ozone, and the possibility of global climate change. As coal is burned in a power plant, its noncombustible mineral content is partitioned into bottom ash, which remains in the furnace, and fly ash, which rises with flue gases. Two other by-products of coal combustion air-pollution control technologies are flue gas desulfurization (FGD) wastes and fluidized-bed combustion (FBC) wastes. This paper analyzed and summarized the generation, characteristics and application of TPP solid wastes and discussed the potential effects of such solid wastes on the environment. On this basis, a review of a number of methods for recovery of metals from TPP solid wastes was made. They usually contain a quantity of valuable metals and they are actually a secondary resource of metals. By applying mineral processing technologies and hydrometallurgical and biohydrometallurgical processes, it is possible to recover metals such as Al, Ga, Ge, Ca, Cd, Fe, Hg, Mg, Na, Ni, Pb, Ra, Th, V, Zn, etc., from TPP solid wastes. Recovery of metals from such wastes and its utilization are important not only for saving metal resources, but also for protecting the environment. 相似文献