最新刊期
卷 0 ， 期 0 ， 2020
- 摘要：Noise pollution is becoming a serious problem due to its great adverse effects on the development of economy and human health.Therefore,how to control the noise and develop excellent sound absorption materials to prevent the noise pollution is an important and urgent issue.Recent progress in sound absorption materials based on polymer fibers is reviewed.This paper begins with the development of acoustical fibers,and then focuses on the research of polymer fibers.The sound absorption mechanism,the influence factors in acoustic performance and the relationship between the structure and acoustic properties of the polymer fibers are introduced.The prospect of these materials is proposed.关键词：Polymer;Fiber;Structure;Sound absorption
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发布时间：2022-09-18 - 摘要：In this paper, the broad develo pment prospect of polyester fiber was confirmed. Directly melt spinning was reg arded as the key technology to produce the fiber. Besides, the prominent cont radictions between a variety of present polyester fibers was emphasized. The melt directly spinning with on-line addition was classified into four types according to characte ristics of mixers in mixing devices. The characteri stics of various on-line addition devices were int roduced respectively and the processes to produce differential po lyester fiber were described to gether with exactcases. Among other things, the international advanced dynamic mixer for high viscous fluid was investig ated. Ultimately, the melt directly spinning with on-line addition was considered as main technology to produce differential and functional polyester fiber.关键词：Polyester;Differential fiber;Melt directly spinning;On-line addition
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发布时间：2022-09-18 - 摘要：Polyhydroquione (PHQ) is a polymer that only contains quinone and hydroquinone groups in its main chain.PHQ retain the characters of quinones,such as redox activity and reversibility consisting of two electron transfer.Compared with monomer,the polymer PHQ has shown improved heat-resistance.As a redox polymer,PHQ has a low redox potential and a fast electron transfer rate, and has been used as an electron mediator for bio-sensors and as an antioxidant or a redox polymer agent since it can capture radicals quickly.The progress on the preparation of PHQ,and on the study of their structure and redox properties and applications is summarized.关键词：Poly(hydroquinone) (PHQ);Oxidative polymerization;Reversibile redox;Electron mediator;Antioxidant
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发布时间：2022-09-18 - 摘要：The interesting blue emission from poly (amido amine) (PAMAM) dendrimers and dendritic polymers as well as small molecules containing amino group,in which case there is no traditional fluorophore unit in the structure,was reproted in recent years.The intensity of fluorescence was found to vary by changing experimental conditions such as pH value,aging time,temperature,and adding oxidant.Compared to organic materials bearing traditional fluorescent chromophore,this new kind of organic fluorophores can find applications in many fields,especially in the biomedical field, because this kind of materials possesses excellent biocompatibility and unique mimic properties of biological macromolecules.To summarize the important results of recent studies,this review shows the optimal conditions,application challenge,fluorescence merit and its attractive property.The trends of research and development of this new kind fluorescence are also described.关键词：Fluorescence;PAMAM dendrimer;Without fluorophore;Biocompatibility;Fluorescence labeling
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发布时间：2022-09-18 - 摘要：Resistant starch ( RS ) refers to the portion of starch and starch products that resist digestion as they pass through the gastrointestinaltract. RS appears to confer considerable efficacy to prevent type Ⅱ diabetes, adiposity, cardiovascular or cerebro vascular diseases, and colorectal cancer. It has been a new focus in food chemistry research area. In recent years, comprehensive research has been conducted oN RS producing technology in China and much progress has been made. In this paper, we reviewed the principles of RS producing techno logy as well as its latest research progress in China, and also gave a prospect of the application of RS in food chemistry industry, in order to provide helpful info rmation for RS technology improvement.关键词：Resistant starch;Producing technology;Research progress
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发布时间：2022-09-18 - 摘要：Amines, as a class of reducing agents, can yield hig hly-active radicals via redox init iation with oxidizing agents. Thus, certain amine-containing vinylic monomers, defined as intrinsically reducing inimes, would be involved in both redo xinitiation and radical propagation steps. finally leading to hyperbranched polymers. In this review, we summarized the amine-involved redo x-initiation systems and their mechanisms, subsequently follow ed by the redo x-initiated radical polymerization of int rinsically reducing inimers in the presence of peroxides, diary lketones, high oxidation-state t ransition metal salts and supernormal valence transition metal complexes. At last, the formation and development of the branching architecture in the redox-ini tiated radical polymerization of intrinsically reducing inimers were discussed in the co ntext of the self-condensing atom transfer radical polymeri zation of int rinsically oxidizing inimers.关键词：Amine;Redox initiation;Intrinsically reducing inimer;Radically polymerizable redox initiating system;Hype rbranched polymer
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发布时间：2022-09-18 - 摘要：Chitosan is the only natural occurring basic poly saccharide containing amino groups, which shows favorable biocompatibility, low-toxicity, biological degradability, and is suitable for preparing micro spheres. In this paper, the preparation methods of chitosan micro spheres are reviewed, which include spray drying, emulsion crosslinking, layer-by-lay er self-assembly, interfacial polyme rization, solvent evapo ration and ionotropic gelation method. The advantages and disadvantages of different methods are discussed. Chitosan microspheres can immobili zed enzyme or cells, and has wide prospect in application for carrier drugs. The application of chitosan micro spheres in immobilized enzyme or cells and embedding drugs is also reviewed.关键词：Chitosan;Microspheres;Biology and medicine;Application
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发布时间：2022-09-18 - 摘要：Mesoporous materials are potentially used in catalysis,absorption and separation. Lately, researchers applied the order channel of the material as microreactor for monomer polymerization.Many polymerizations were carried out within the channel,including free radical polymerization and non-free radical polymerization.The latest 20 yearʾs progress of the non-free radical polymerizations in the channel of mesoporous molecular sieve was reviewed.These polymerizations included the oxidative polymerization,coordination polymerization,condensation polymerization,ringopening polymerization and ionic polymerization.Some effects on the polymerization and polymer composite were discussed.The application fields of the obtained polymer/mesoporous composites were overlooked.关键词：Progress;Mesoporous material;Channel;Non-free radical polymerization;Application
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发布时间：2022-09-18 - 摘要：Microemulsion polymerizat ion is effective in producing transparent stable micro latexes, which have potential applications, such as in coating, catalyst or drug delivery. In this paper, the new progress of high solid content microemulsion polymerization was reviewed. Two approaches were reviewed: one using high effective surfactant system; the other approach employing methods to improve microemulsion polyme rization. The development tendency of high solid content microemulsion polyme rization was also prospected.关键词：High solid content;Microemul sion polymerization;High effective surfactant;Polyme rization technique
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发布时间：2022-09-18 - 摘要：The cellulose-poly (BMA) graft copolymer oil absorption resins has been synthesized from butyl methacrylate modified cotton pulp (cellulose) which initiated with ceric ion /HNO3 solution by shake graft copolymerization using porcine pancreatic lipase as catalyze, N,N′-methylene-bisacrylamide as crosslinker.Structure of the cellulose-poly (BMA) graft copolymer was characterized by means of FT-IR、XRD、SEM、TG、DSC etc.Effects of the process of initiating cotton pulp and graft copolymerization condition were investigated.The ideal cellulose-poly (BMA) graft copolymer oil absorption resins could be prepared when the cotton pulp initiated with 0.15mol/LHNO3solution of containats ceric ion at 45℃ for 2.5h,then reacted with BMA by using porcine pancreatic lipase as catalyze,N,N′-methylene-bis-acrylamide as crosslinker.Under the optimal conditions of m (cellulose): m (initiator): m (monomer): m (porcine pancreatic lipase): m (crosslinker) =1∶0.03∶1.5∶0.02∶0.02, 50℃ and 24h,the graft yield and oil pick-up abilities of the synthesized cellulose-poly (BMA) graft copolymer oil absorption resins are choiceness.关键词：Porcine pancreatic lipase;Cellulose;Butyl methacrylate;Graft copolymerization;Oil absorption resins
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发布时间：2022-09-18 - 摘要：A series of novel rapidly responsive P( AAEA/AMPS/AA) hydrogels with interco nnected superpo rous structure were synthesi zed by foaming dispersion copolyme rization using 4-acetyl acryloyl ethyl acetate ( AAEA), 2-acrylamide-2-methylpro panesulfonic acid ( AMPS) and acrylic acid ( AA) as monomers. Results showed that when the mole fraction of initiator and that of crosslinker were 2.5 % and 0.6 % respectively, the equilibrium swelling ratios were highest. The hydrogels had uniform and interconnected porous structure when using the saturated solution of sodium carbo nate ( Na2CO3 ) as foaming agents, and pores formed in the surface of hydrogel could increase the contact area between hydrogels and solvent after being treated by ethanol. The hydrogels could reach their swelling and deswelling equilibrium within 20s, and they had favo rable ion sensitivity and repeatability be tween distilled water and NaCl solution.关键词：Hydrogel;Foaming dispersion copolymerization;Rapid response;Ion sensitivity
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发布时间：2022-09-18 - 摘要：Starting from L-lactic acid,poly (L-lactic acid) with low polymerization degree was first synthesized through direct melt polycondensation with composite catalyst.Then PLLA with higher molecular weight was obtained by solid-state polymerization with different temperature controlling. The conditions of solid-state polymerization were especially studied.Viscosity measurements and gel permeation chromatography (GPC) were used to measure intrinsic viscosity and molecular weight of resulting PLLA polymers,respectively.The differential scanning calorimetry (DSC) was used to characterize the melt properties and crystallinity of PLLA.The results showed that under absolute pressure 80 Pa with subsection temperature controlling (first at105℃ for2.5h,then at145℃ for35h, the molecular weight ( Mw ) of PLLA is 426,000,which is 36 times higher than that of PLLA first prepared by melt polycondensation. The Tm and crystallinity ( Xc ) are 189.6℃ and 69.25% , respectively.Preparation of high molecular weight polylactic acid provides direction for its industrial production of the new method.关键词：L-Lactic acid;Solid-state polymerization;Biodegradable material
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发布时间：2022-09-18 - 摘要：The crystallinity of polypro pylene, grain size and distribution, and the morphology of spherulite affect its mechanical properties greatly, especially the impact strength. Polypropylene alloy has better impact strength for its smaller spherulite and more defect in spherulite. And polypropylene alloy has better performance if the spherulite has moderate size and uniform distribution. The crystallinity of copolymer also affect the mechanical properties of polypropylene alloy, and increasing the crystallinity of copolymer mayincreasing its impact strength.关键词：Polypropylene alloy;Crystalli zation behavior;Mechanical property
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发布时间：2022-09-18 - 摘要：Based on density functional theory computations for polymerization reaction mechanisms via metallocene and neutral salicyladiminato palladium (II) and nickel (II) catalysts,the correlation between regioselectivity and Mulliken site charge in catalyzed olefin polymerization was discussed from the view of reactants and transition states. The effects on regioselectivity of the catalyzed polymerization by reactants and transition states are significantly different.The reactant influences regioselectivity of a reaction by the site charge effect on frontier orbits,while the transition state influences regioselectivity by the site charge delocalization.Different regioselectivity results in two different polymerization mechanisms: 1,2-and 2,1-insertion polymerization mechanisms.1,2-insertion mechanism gives a cation intermediate,while2,1-insertion mechanism gives an anion intermediate.The more delocalized the charge on a cation in the transition state is for a catalyst configuration,the lower the active energy will be for1,2-insertion reaction of that configuration; the more delocalized the charge on an anion in the transition state is,the lower the active energy will be for 2,1-insertion.Thus the regioselectivity is different for different catalyst configurations.And this difference is correlated with the charge distribution in the catalyst.Only Mulliken charges are correlated very well,possibly because it originated from the coefficients of the orbitals.Material design is a very important topic in scientific research.So the conclusions of correlation between regioselectivity and Mulliken site charge in catalyzed olefin polymerization are significant for olefin polymer design.关键词：Catalyzed Cross-Coupling reaction;Regioselectivity;Site charge;Olefin polymerization;Catalysis
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发布时间：2022-09-18 - 摘要：The "Experiments of Polymer Physics" course is an essential part in the teaching of Polymer Physics.It is proposed that this experimental course could be designed in three levels: (1) the first level is the elementary experiments,which serve to strengthen the students’fundamental concepts and experimental skills of polymer physics; (2) the second level is the in-depth experiments,which inspire the students to thoroughly think over the elementary experiments; and (3) the third level is the comprehensive experiments containing both frontier experiments and interdisciplinary experiments related with polymer chemistry and physics as well as polymer engineering.With such three-level experiments,the students are trained step by step to solidify their understanding of polymer physics,to grasp their experimental skills,and to enhance their team-working capabilities like communication and cooperation with others.Furthermore,several ideas of ways of teaching and class management are also suggested.关键词："Experiments of Polymer Physics";Design in levels;Class management;Ways of teaching
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发布时间：2022-09-18 - 摘要：These days, there are some shortages in the experimental course of polymer processing. Every part of experimental course is isolated. And the cultivation of overall quality for students can not be realized. This work integrates the independent experiments and establishes innovated system. The innov ation of experimental system for polymer processing, which refers to the production modes of factories of polymer materials, includes two interconnected segments: the design for formula and the techniques of processing. The experimental items are set up from universities, factory and even students themselves. It is better to understand the polymer processing for students by takeing part in every segment of experimental system. Moreover, the content of experimental system is widened greatly through part icipating scientific research, settling technical problem and starting an undertakeing. The innovation of experimental system for polymer processing is helpful to cultivating overall quality of students.关键词：Polymer processing;Innovation;Practical segment;Experimental system
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发布时间：2022-09-18 - 摘要：The construction of excellent curriculum can promote subject construction and the cultivation of faculty team to improve the teaching quality to a new level.Based on the model curricula construction of polymer chemistry, this paper introduced the process of excellent curriculum construction of polymer chemistry,the characteristic has been formed in performing teaching procedure of production practice,the cultivation of teachers’engineering practical capability,college students’ engineering practical and handling capability through close cooperation of production,education and research with factories.Some precious experience has been obtained through exploration in the construction of subject system,in theoretical and practical reform of teaching contents and methods, and in the promotion of faculty team.关键词：Polymer chemistry;Curriculum construction;Subject construction;Faculty team
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发布时间：2022-09-18
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