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1.
The past two decades have witnessed significant developments in the study of water‐soluble cellulose derivatives. Numerous new water‐soluble cellulosic polymers have been synthesized and studied for diversified applications including rheology modification, personal care and oilfield formulation, surface coating, colloid stabilization, and precious metal‐ion recovery. These cellulosic polymers involve mainly hydrophobically‐modified water‐soluble cellulose derivatives with lipophilic‐hydrophilic groups, water‐soluble cationic cellulose derivatives with quaternary ammonium groups, water‐soluble amphoteric cellulose derivatives with both acidic and basic groups of different strengths, as well as water‐soluble sulfur‐containing cellulose derivatives. Unlike common water‐soluble cellulose derivatives known for a long time, these modified polysaccharides provide special and high properties or multi‐functions for their utilization. In this article, a brief review is given regarding their research and development.  相似文献   

2.
聚丙烯酰胺类水溶性聚合物制备中分子量的控制   总被引:1,自引:0,他引:1  
聚丙烯酰胺类水溶性聚合物在油气开采过程中有着十分广泛的应用,其分子量的大小决定着产品的性能和用途。该类聚合物的合成一般采用自由基聚合,聚合反应中通过控制单体浓度、引发剂浓度、聚合反应温度可以调节聚合物的分子量。另外,通过选择引发体系、聚合工艺、适度交联以及添加链转移剂也可以达到控制聚丙烯酰胺类水溶性聚合物分子量的目的。  相似文献   

3.
Polyacrylamide‐based (PAM) polymers are the most widely used synthetic water‐soluble polymer so they are applied in a range of industries. However, they suffer from a number of limitations which requires the development of synthetic routes that can accurately control polymer structure and hence function. This study describes a carbodiimide mediated coupling reaction (CMC) that is used to generate modified polyacrylamide (PAM) including hydrophobically modified water‐soluble polymers (HMWSP). The reaction proceeds efficiently in water and does not require organic solvents or high temperatures. The approach is flexible due to the efficiency of the CMC reaction allowing for accurate control over polymer structure and function. This is confirmed using acid‐base titration, spectroscopy, viscometry, and rheology. The viscosity of the polymers varies over a broad range with those containing larger hydrophobic group (dodecyl) showing the highest viscosity. The hydrophobicity of the pendent group determines how it influences viscosity and using this new synthetic approach polymer with the same molecular weight can be compared. Linear hydrocarbon pendent groups are more hydrophobic than the cyclic versions resulting in higher viscosity. However, the spatial arrangement of the pendent group (linear or cyclic) also affects the viscosity at higher pendent group contents. The number of modified PAMs that can be generated is expansive because the approach works with a number of different functional groups and base polymers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42797.  相似文献   

4.
A systematic comparison has been performed of the morphology and stability of microtubules (MTs) induced by the potent microtubule‐stabilizing agents (MSAs) taxol, epothilone B (Epo B), and discodermolide (DDM) under GTP‐free conditions. DDM‐induced tubulin polymerization occurred significantly faster than that induced by taxol and Epo B. At the same time, tubulin polymers assembled from soluble tubulin by DDM were morphologically distinct (shorter and less ordered) from those induced by either taxol or Epo B, as demonstrated by electron microscopy. Exposure of MSA‐induced tubulin polymers to ultrasound revealed the DDM‐based polymers to be less stable to this type of physical stress than those formed with either Epo B or taxol. Interestingly, MT assembly in the presence of both DDM and taxol appeared to produce a distinct new type of MT polymer with a mixed morphology between those of DDM‐ and taxol‐induced structures. The observed differences in MT morphology and stability might be related, at least partly, to differences in intramicrotubular tubulin isotype distribution, as DDM showed a different pattern of β‐tubulin isotype usage in the assembly process.  相似文献   

5.
The antibacterial activity of insoluble pyridinium‐type polymers with different structures against Escherichia coli suspended in sterilized and distilled water was investigated by a colony count method. The results show that the antibacterial activity of insoluble pyridinium‐type polymers, except for one containing I, is characterized by an ability to capture bacterial cells in a living state by adsorption or adhesion, with the process of capturing bacterial cells being at least partially irreversible. This feature differs from the antibacterial activity of the corresponding soluble polymers, which is characterized by the ability to kill bacterial cells in water. In addition, insoluble pyridinium‐type polymers can also capture dead bacterial cells. This implies that insoluble pyridinium‐type polymers possess broad prospects for development in new water treatment techniques and whole‐cell immobilization techniques. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 676–684, 2000  相似文献   

6.
王媛  景惧斌  周海涛 《广州化工》2012,40(13):90-91,105
为了更好的解决煤炭运输过程中的扬尘问题,采用高分子聚合物、水溶纤维素聚合物为原料,利用正交实验法研制了一种满足生态要求的集粘结、吸湿和保水为一体的复合型化学抑尘剂。通过测试该抑尘剂的抗风性能,结果表明:新型抑尘剂在常温下溶解性好,抑尘效果好,固化层具有一定的强度,具有实际应用价值。  相似文献   

7.
黄棋尤 《国外塑料》2003,21(3):27-30
就利用液晶聚合物特性的新材料开发,对高循环成型材料和流动性和机械物性同时改性的填料应用、耐热新规格聚合物的骨架、精密成型材料及其回收再生适应性作了说明。  相似文献   

8.
Using hydrophilic polymers to control nutrient release   总被引:30,自引:0,他引:30  
Using diverse technological approaches, many types of delivery devices have been used to supply plant nutrients at a controlled rate in the soil. One new approach is the use of hydrophilic polymers as carriers of plant nutrients. These polymers may be generally classified as 1) natural polymers derived from polysaccharides, 2) semi-synthetic polymers (primarily cellulose derivatives), and 3) synthetic polymers. By controlling the reaction conditions when forming the polymers, various degrees of cross-linking, anionic charge, and cationic charge can be added, thereby changing their effectiveness as fertilizer carriers.When fertilizer-containing solutions are mixed with hydrophilic polymers to form a gel prior to application in the soil, the release of soluble nutrients can be substantially delayed compared with soluble fertilizer alone. The effectiveness of a specific controlled-release polymeric system is determined in part by its specific chemical and physical properties, its biodegradation rate, and the fertilizer source used. Addition of some polymers with nutrients has been shown to reduce N and K leaching from well-drained soils and to increase the plant recovery of added N, P, Fe, and Mn in some circumstances  相似文献   

9.
Waterborne polymer dispersions are widely used in coatings and graphic arts markets as environmentally friendly and more sustainable alternatives to solvent borne binders. Traditionally, waterborne (meth)acrylic dispersions are prepared by emulsion polymerization using low molar mass surfactants as a key ingredient to control particle size. However, these surfactants can have a negative influence on the performance of coatings such as reduced water resistance and adhesion. To mitigate the negative effects of surfactants, polymer latexes have been developed that employ alkaline‐soluble polymers as the sole stabilizer for a subsequent emulsion polymerization step. In this way surfactant‐free polymer dispersions are obtained. Despite the high commercial impact and relevance of this technology, fundamental studies regarding the physicochemical properties of the alkaline‐soluble polymers are lacking. In this article, the synthesis and colloidal properties of alkaline‐soluble waterborne methacrylic copolymers are reported. The dissolution behavior and colloidal properties of these alkaline‐soluble polymers were studied as function of molar mass, acid content, and pH. The dissolving polymer particles were characterized using static and dynamic light scattering, static and dynamic surface tension measurements, and cryogenic‐transmission electron microscopy analysis. It is concluded that the dissolution mechanism of alkaline‐soluble polymers follows a gradual process. As the pH increases deprotonation of the carboxylic acid groups swells the particle enhancing the further swelling with water. At a certain amount of base, the particles disintegrate into small polymer aggregates while the most water‐soluble polymer chains are dissolved in the water phase. An important learning is that part of the alkaline‐soluble polymer resides in very small particles (<5 nm). The formation of these polymer particles below 5 nm was not reported previously and offers a new insight into the dissolution mechanism of alkaline soluble polymers. The most important parameter steering this process is the acid value of the polymer, while the molar mass plays a modest role. The understanding gained in this study can be used to further advance alkaline‐soluble polymers as stabilizer in surfactant‐free emulsion polymerization technology, improving the performance of a wide range of industrially relevant coatings. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46168.  相似文献   

10.
刺激-响应型水溶性聚合物的研究进展   总被引:1,自引:0,他引:1  
马俊涛  赵林  黄荣华 《化学世界》2001,42(11):608-614
对刺激响应型水溶性聚合物近年来的发展进行了综述。介绍了能够对 p H、温度、光、电解质、电场、分子、剪切等外界刺激做出响应的水溶性聚合物 /凝胶的结构特点、响应机理和研究现状  相似文献   

11.
Biodegradable polymers of poly(lactic acid) (PLLA) and synthesized in‐house poly(trimethylene carbonate) (PTMC) with admixture of water‐soluble methyl cellulose (MC) were used for development of nerve guidance tubes for peripheral nervous system regeneration after injury. Fabrication method involved phase separation of viscous dixane solution of polymers mixture seat on a rod in a proper nonsolvent, which resulted in tubular structure of large porosity. Influence of electron beam sterilization on molecular weight, thermal properties of the polymers, and mechanical performance of the tubes was evaluated. Admixture of hydrophilic MC to synthetic polymers resulted in modification of mechanical properties of the channels. Extraction of MC showed potential of the tubes for releasing water‐soluble bioactive molecules, such as for instance growth factors. Basic in vitro MTT and LDH assays showed no cytotoxic effect of manufactured tubes, therefore, animal experimentations may be considered. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

12.
Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia.At present,there are a variety of products,such as slurry monoammonium phosphate (MAP),diammonium phosphate (DAP),industrial grade MAP,water soluble MAP,water soluble ammonium polyphosphate (APP) and so on.After more than 60 years of development,China's ammonium phosphate fertilizer industry has experi-enced the road of from scratch and from weak to strong.The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore.The continuous,stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China.The development of new ammonium phosphate fertilizer products,such as industrial grade MAP,water soluble MAP,water soluble APP,pro-vides technical support for the transformation and upgrading of phosphorus chemical enterprises.In this paper,the production methods,the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.  相似文献   

13.
我国冷却水处理剂的现状与未来   总被引:3,自引:0,他引:3  
鲍其鼐 《上海化工》1999,24(16):4-7,22
综述了国内外冷却水处理剂包括水溶性聚合物、有机膦酸、氧化与非氧化性杀生剂的发展。参照国外发展趋势并结合国内情况,讨论了有关冷却水处理剂的研究、生产、应用等问题,同时提出了看法和建议。  相似文献   

14.
A novel ring-closure method was developed to specifically focus on the preparation of water soluble cyclic polymers. The well-defined linear polymers were synthesized by a standard RAFT polymerization using a functional RAFT agent 1. The cyclic polymers were then obtained by virtue of an efficient bromomaleimide-thiol substitution reaction to ring-close the linear precursors. This technique is unique in that it not only produces various well-defined water soluble cyclic polymers with high efficiency and topology purity, but also employs the environmentally benign solvent, water, as the ring-closure reaction media.  相似文献   

15.
In a previous study, we reported water‐soluble light‐emitting nanoparticles with distinct interchain aggregation states of the constituent conjugated polymers. These interchain states usually result in strong self‐quenching, dramatically reducing the quantum efficiency of fluorescence. In the work reported in the present study, we developed new water‐soluble fluorescent nanoparticles without distinct aggregation of the conjugated polymer chains, which demonstrated distinctive morphologies and optical properties. ‘Strawberry’ morphologies of the nanoparticles were directly observed using transmission electron microscopy. The conjugated polymers were dispersed in the individual cores of the nanoparticles and the majority of the core diameters were in the range 8–12 nm. The primary optical properties of the conjugated polymers in tetrahydrofuran still remained in the nanoparticles. The results suggest that the conjugated polymer chains formed a possible unimolecular structure without distinct aggregation in the nanoparticles. Copyright © 2010 Society of Chemical Industry  相似文献   

16.
We have developed new photopolymers that have superior waterproof properties and that can easily interact with polyfunctional acrylate compounds, thus serving as hydrophobic photocrosslinking reagents. Acryloylmorpholine monomers whose homopolymers were less moisture absorbing than the usual water‐soluble polymers but were still water soluble to a good degree, were copolymerized with other acryloyl monomers. We then introduced the photosensitive (meth)acryloyl group to side chains of the resulting polymers. Among six copolymers examined, the copolymers composed of acryloyl morpholine, hydroxyethyl acrylate, ethyl, or methyl methacrylate, and methacryloyl isocyanate were found to have nicely balanced hydrophilicity and waterproof properties, in addition to good compatibility with hydrophobic photocrosslinking reagents. The composite polymers thus obtained were confirmed to be promising photopolymers usable even in a highly humid environment. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 684–692, 2003  相似文献   

17.
We report in this article an improved procedure to isolate and purify representative water‐soluble polyphosphazenes that dramatically reduces the time and equipment involved, while maintaining or exceeding the yields and purity reported in the literature for these polymers obtained using dialysis methods. This technique takes advantage of the phase transition behavior exhibited by some hydrophilic polymers, namely that associated with the lower critical solubility temperature (LCST). The polymers used in this study were poly[bis‐(2‐(2‐methoxyethoxy)ethoxy)phosphazene], MEEP (1), and two new water‐soluble polymers. These polymers are similar to MEEP, yet they contain a small percentage of a crosslinkable pendant group; either 2‐hydroxyethyl allyl ether (2), or o‐allyl phenol (3). The observed behavior was quite different for these two polymers than that found for MEEP, and is a direct consequence of the pendant group substitution patterns. Although the homopolymer MEEP yielded a single sharp LCST point, the two heteropolymers exhibited this phase transition over a broader temperature range. Further, fractionation of polymer 3, based on pendant group speciation, was possible due to the more hydrophobic nature of the phenol. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1092–1099, 2000  相似文献   

18.
司徒粤  黄洪  胡剑峰  傅和青  陈焕钦 《精细化工》2006,23(11):1041-1047
随着石油资源日益枯竭,寻找优质、廉价的石油代用品是聚合物工业存在和发展的关键。植物油是聚合物材料合成最有希望的石油替代原料之一,成为近年来的研究热点。该文评价了植物油基聚合物的发展现状和最新研究进展,介绍了某些聚合反应机理,还具体介绍了植物油基聚合物包括环氧树脂、聚氨酯、聚酯的合成方法。引用文献47篇。  相似文献   

19.
The rapid development of two new classes of electrically active polymer materials, electronically conducting and electroactive polymers and ion-conducting polymers respectively, offers new possibilities for application of both classes of material, especially in combination with each other. While some of these combinations have been attempted before, they all met serious problems due to poor interpenetration of the two polymers. The recent availability of solubilized and soluble electroactive and conductive polymers has greatly advanced the possibilities of reducing the interpenetration problem. Some experimental studies using the combination of solubilized electroactive polypyrrole with poly(ethylene oxide) in an electroactive polymer blend electrode for solid-state polymer batteries are discussed. The opportunities for using polymer blends for solid-state electrochemical polymeric devices, and avenues for the development of materials for such devices, are also reviewed.  相似文献   

20.
This paper is an overview of the versatile polymer materials containing different functional groups at the main or side chain to remove hazardous inorganic species. These materials include water‐insoluble, nanocomposite and water‐soluble polymers. Water‐insoluble polymers and nanocomposites are used in adsorption and ion exchange processes, whereas water‐soluble polymers are employed with ultrafiltration membranes in the liquid‐phase polymer‐based retention technique. © 2015 Society of Chemical Industry  相似文献   

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