最新刊期
卷 36 ， 期 3 ， 2023
- 摘要：Due to the high melting point and poor solubility of ethylene/carbon monoxide alternating copolymerization products, there are great difficulties in material processing and application. The catalyst design can realize the non-alternating copolymerization of ethylene/carbon monoxide, reduce the carbonyl content in the copolymer and improve the processability of the material. This paper reviews the progress of neutral transition metal catalysts, cationic transition metal catalysts and metal carbonyl compounds in the non-alternating copolymerization of ethylene and carbon monoxide. Finally, the research of new photodegradable plastics is prospected.关键词：Ethylene/Carbon monoxide copolymerization;Transition metal catalysts;Non-alternating polyketone;Photodegradable plastics
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发布时间：2023-01-16 - 摘要：Polymer electrolyte (PE) is attractive for the next generation of high energy density lithium batteries, with the advantages of no liquid leakage, good interface compatibility, thermal and chemical stability, and simple preparation process. Unfortunately, PE could not meet the requirements of both mechanical and electrochemical properties at the same time for lithium batteries. In order to improve the comprehensive properties of PE, PE matrix has been modified via blending, crosslinking and so on. It is known that the composition and structure of PE matrix obtained by traditional free radical polymerization are not easy to control, which hinders the application of PE. As a new polymerization technology, atom transfer radical polymerization (ATRP) can regulate the molecular weight and conduct structure design of polymers by maintaining the low concentration of free radicals through the reversible balance between active and dormant species. It provides an effective way for the preparation of PE with both high mechanical and electrochemical properties. Additionally, ATRP has outstanding features in the modification of inorganic filler and the optimization of interface performance, due to the designability of ATRP initiator group. This is of great significance for the improvement of the comprehensive performance of lithium battery with PE membrane based on polymer matrix nanocomposites. This review summarizes the application of ATRP technology in the preparation of PE matrix, filler modification as well as interface optimization. The future development directions of ATRP used in PE are also prospected.关键词：ATRP;PE;Structural design;Filler modification;Interface optimization
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发布时间：2023-01-16 - 摘要：Due to their excellent properties such as heat resistance, chemical resistance and low surface energy, fluorine-containing compounds exhibit excellent properties when designing functional polymers with special functions and specific chemical and physical properties. However, at present, most fluoropolymers are still obtained by traditional free radical polymerization, and it is difficult to control the polymerization process of the polymer, which makes it difficult to construct fluoropolymers with new structures. With the development of controlled/living radical polymerization methods, such as atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT),and ring opening metathesis polymerization (ROMP), it is possible to construct fluoropolymers with novel structures. Through precise control of the polymerization process and structure of fluoropolymers, fluoropolymers with a "comb" structure can be obtained by combining the three grafting methods of "grafting-from" , "grafting-to" and "grafting-through" . Due to the high temperature self-migration of the fluorine-containing segment, the fluorine-containing segment is used as a "comb segment" , which makes it have unique physical and chemical properties, and has great performance advantages and application prospects in high-end fields such as optoelectronics and biomedicine. In this paper, the construction of the "comb" structure of fluoropolymers and the application of its functional materials are reviewed, and its future development direction is prospected.关键词：Fluoropolymer;Comb-shaped;Grafting methods
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发布时间：2023-01-16 - 摘要：The performance of carbon fiber precursor determines the final performance of carbon fiber to a great extent. Few defects, fine denier, high orientation and high purification are the basic requirements of high-performance precursor. The orientation degree of precursor largely determines the orientation structure of graphite like lamella formed during the pre oxidation and carbonization of carbon fiber, which will affect the final strength and modulus of carbon fiber. Therefore, it is of great significance to prepare highly oriented carbon fiber precursor. This paper focuses on the preparation process of highly oriented carbon fiber precursor, first analyzes the importance of highly oriented precursor, then summarizes and analyzes the influence of spinning method and drafting process on the degree of orientation in the precursor preparation process, and introduces the calculus nano stacking method and the preparation process of highly oriented composite fiber precursor. It is pointed out that high-quality primary fiber and precursor with stable orientation arrangement are the key to the preparation of highly oriented carbon fiber precursor, which is expected to contribute to the research on improving the orientation of precursor and then improving the properties of carbon fiber in the future.关键词：Carbon fiber precursor;Degree of orientation;Process improvement;Composite fiber
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发布时间：2023-01-16 - 摘要：Sulfobetaine amphoteric polymer (pSBMA) has the characteristics of non-specific protein adsorption, ultra-low biological pollution and good biocompatibility. It is widely used in the field of biomedicine in the modification of biomaterials, medical wound dressings and drug carriers, In addition, its excellent antifouling property and diversified surface grafting methods make it show great potential in membrane treatment and surface antifouling and conduction optimization of electronic components.关键词：Sulfobetaine zwitterionic polymer;Non-specific protein adsorption;Biomaterial modification;Wound dressing;Drug carrier
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发布时间：2023-01-16 - 摘要：For insolving the problem of "oil migration" when thermal conductive silicone gel is used in aerospace environment, a polysiloxane with long branched chain is designed and synthesized (B-PDMS), then fill nano-ZnO in it to obtain a thermal conductive silicone gel based on physical entanglement network, and fill the same amount of nano-ZnO in the linear polysiloxane with the same viscosity as comparison samples. Through the characterization of Fourier transform infrared spectroscopy (FTIR) and magnetic resonance spectroscopy (1HNMR), we prove that polysiloxane with long branched chain is synthesized successfully, and we find that BPDMS has larger molecular weight and lower molecular movement ability than L-PDMS with the same viscosity. Through the characterization of environmental scanning electron microscope, thermal conductivity, rheological properties, oil migration performance and total mass loss test, it is found that nano-ZnO has better dispersion in B-PDMS; the thermal conductivity of B-PDMS based thermal conductive gel is lower than that of L-PDMS based thermal conductive gel under the same filling amount; the zero shear viscosity of B-PDMS based silicone gel is higher than that of L-PDMS based silicone gel, but the former has good thixotropy, the viscosity tends to be the same as the latter with the shear rate increasing. Importantly, the oil migration performance of B-PDMS based silicone gel has been greatly improved, the oil migration rate of thermal conductive gel filled with 200 mass parts of nano-ZnO is only 1.08, which basically realizes no oil migration; and its TML is only 0.26 wt%, which meets the requirements of the space environment for the outgassing performance of the material.关键词：Branched chain;Polysiloxane;Physical entanglement network;Thermal conductive silicone gel;Oil miagration
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发布时间：2023-01-16 - 摘要：Because of the excellent comprehensive properties of bio-based poly(butylene succinate) (PBS), it is widely used in food packaging and tableware. However, due to its poor thermal stability, it tends to thermally degrade during processing and use. Therefore, it is necessary to add auxiliaries to improve the thermal stability of PBS. The effects of different auxiliaries on the thermal stability of PBS were evaluated by differential scanning calorimeter calorimetry (DSC), thermogravimetric analysis (TGA), tensile properties, melt flow rate and heat deformation temperature. The results showed that the addition of different auxiliaries could improve the thermal stability of PBS, and the initial decomposition temperature of PBS increased by 3.2 ℃ to 15.2 ℃; On the other hand, compared with the compound auxiliaries, one single additive significantly reduced the melt flow rate of PBS. The melt flow rate decreased to 3.41 g/10 min that decreased by 58.9%, and the tensile strength, heat deformation temperature and elongation at break of PBS increased to 39.1 MPa, 90.2 ℃ and 360% that represent 15.0%, 12.5% and 48.4% increase. The modified PBS has excellent rigidity, toughness and heat resistance at the same time.关键词：Auxiliaries;Poly(butylene succinate);Biodegradable plastics;Thermal stability
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发布时间：2023-01-16 - 摘要：The polymerization condition plays a key role in preparing functional microspheres. In this paper, functional microspheres with impedance protein non-specific adsorption were prepared by the dispersion copolymerization of styrene, functional monomer and allyloxy polyethyleneglycol (APEG) under different polymerization conditions. The particle size, size distribution and functional group of these microspheres were measured by Fourier transform infrared (FT-IR),dynamic light scattering (DLS) and scanning electron microscopy (SEM). It was evaluated resistance non-specific adsorption by mean of immobilized protein on two kinds of functional microspheres. The experimental results indicated that APEG could act as a functional monomer to obtain functional microspheres with narrow size distribution under a certain condition. Moreover, it was found that poly (APEG) could act as a stabilizer in dispersion copolymerization when its molecule weight increased a certain value by self-polymerization under dispersion medium with water. Furthermore, the adsorption capacity of bovine serum albumin (BSA) per gram of P(St-co-APEG) microspheres was 0.66 mg, while that of BSA per gram of P(St-co-GMA) microspheres was 4.8 mg. In a word, APEG functional microspheres with resistance to protein adsorption were successfully prepared by dispersion copolymerization via optimizing the polymerization condition.关键词：APEG functional microspheres;Resistance of protein adsorption;Dispersion copolymerization;Surface morphology
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发布时间：2023-01-16 - 摘要：A series of different urethane/urea polyester polyurethanes (polyester-PU) with various diols were synthesized by poly(2-methyl-2,4-pentadiol adipate) diol as soft segment,2,4-2,6 mixed toluene diisocyanate (TDI T-80),isophorone diamine (IPDA),glycol (EG),1,2-propylene glycol (PG),1,4-butanediol (BDO) and neopentyl glycol as hard segment.Fourier transform infrared (FTIR) spectroscopy was used to investigate the effect of ester carbonyl, carbamate/urea linkages, and mixed toluene diisocyanate structures on carbonyl hydrogen bonding under the constant total hard segment content. The results showed that in the role of polyester polyol ester carbonyl group, there are six absorption peaks in the infrared spectra of urethane carbonyl and ester carbonyl region of polyester polyurethane resin. —C=Oint not formed hydrogen bonds, and —C=Oext part formed hydrogen bonds, the degree of —C=Oext hydrogen bond increases from 5% to 9% with the increase of the chain extension ratio of small molecule diol. When the hard segment content of polyester polyurethane resin was about 20%, free urethane carbonyl and ester carbonyl were mainly 60%.With the increase of urethane/urea, under the combined influence of the asymmetric structure of 2,4-TDI, the degree of H-bonded urethane carbonyl and urea carbonyl in the polyester-PU decreased, free urethane carbonyl, ester carbonyl and urea carbonyl increased, which indicated that the microphase seperation of the polyester-PU was weakened, the mixing of soft and hard segments was enhanced. The degree of H-bonded urea carbonyl overall was a small proportion 6%. P was 0.25, the degree of H-bonded urethane carbonyl in P-PU was larger, and then decreased.关键词：Polyester-polyurethane;Mixed toluene diisocyanate;Ratio of urethane/urea;Carbonyl;Hydrogen bond
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发布时间：2023-01-16 - 摘要：The self-assembly behaviors of AB cyclic symmetric diblock copolymers confined in thin films were investigated by Monte Carlo simulation. The simulation results show that the orientation of the lamellar structure formed by AB cyclic symmetric diblock copolymers in the films depends on the selectivity of the film surface or the film thickness. When the film surface is neutral or has strong selectivity, the orientation of the lamellar is vertical or parallel to the film surface, respectively; When the film surface selectivity is weak, the orientation of the lamellar structure changes from vertical to parallel to the film surface with the increase of the film thickness. These simulation results are in good agreement with the linear systems reported in the literature. However, it is worth noting that when the selectivity of the film surface is moderate, a novel ordered structure with wavy-like structure, not observed in the linear system, is formed in the cyclic copolymer system. By analyzing the interaction enthalpy density and the chain conformation of the structure, it is found that the structure is a stable structure. In addition, by comparing the lamellar structures of the cyclic system and the linear system under the same parameters, it is found that the characteristic size of the lamellar structure of the cyclic system is significantly smaller than that of the linear system. The simulation results above show that compared with linear block copolymers with the same molecular weight, cyclic block copolymers can form novel or smaller characteristic size microphase separation structures due to their special geometric structure. Controlling the characteristic size, especially obtaining the smaller characteristic size, is of great significance for the preparation of microelectronic devices with smaller nanostructures and higher integration.关键词：Cyclic diblock copolymer;Self-assembly;Monte Carlo simulation;Thin film
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发布时间：2023-01-16 - 摘要：In view of some long-standing problems in the integration of industry and education in the field of polymer materials and engineering, we pointed out that the inconsistency between the advantages and disadvantages of industry and education integration on both sides of industry (enterprises) and education (universities) is its main source. Combined with some practice and exploration of our specialty in recent years, some measures are taken from both sides of universities and industry, including: coordinating common needs, unblocking communication channels, perfecting incentive mechanism, and meeting the common interests of both sides of industry and education. Thus the long-term mechanism of industry education integration can be fundamentally realized, and which would help to provide a solid foundation for the cultivation of high-level engineering talents in this major.关键词：Industry education integration;Interest integration;Long-term mechanism
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发布时间：2023-01-16 - 摘要：Different from the apparent "three states" and "two transitions" in the modulus-temperature curve of amorphous polymers, the macroscopic performance of the modulus-temperature curve of crystalline polymers is more complicated. Though it is discussed in some polymer physics textbooks and exercises, there is a lack of clear rules and image descriptions. In this paper, the modulus-temperature curve of crystalline polymer is analyzed, in order to solve students' problems and achieve better teaching effect.关键词：Modulus-Temperature curves;Crystalline polymers;Molecular motion;Teaching
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发布时间：2023-01-16 - 摘要：The extent of reaction (p) is an important variable in condensation polymerization. Many equations about the number average of polymerization degree or gel point contain the extent of reaction. There are three kinds of extent of reaction, including the extent of reaction of functional group A (pA), the extent of reaction of functional group B (pB), and the extent of reaction of the polymerization system (pS). Clarifying the physical meaning of the extent of reaction is vital for mastering the equations. From the derivation of these five commonly used equations, the physical meaning of extent of reaction was clarified and compared. By changing the two exercises in the textbook, flaws in students' knowledge can be exposed actively, which is helpful for deepening students' understanding of the extent of reaction.关键词：Condensation polymerization;Extent of reaction;Number average polymerization degree;Gel point
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发布时间：2023-01-16 - 摘要："Observing the morphology of polymer spherulite and measuring the radial growth rate of spherulite by polarizing optical microscope" is a classic experiment item in polymer physics experiment. In the conventional teaching process, this item is just a proof experiment, and the content is relatively simple and boring. On the basis of this classic experiment item, we designed a comprehensive and exploratory experiment whose main content includes the dissolving of polymers, the preparation of films and the study of the crystallization process. The main improvements of the new experiment item are as follows: (1) the uniformity and stability of the samples are improved by using the spin-coating method; (2) the accuracy of the results are improved by using the insitu heating stage and the charge-coupled device (CCD) imaging system; (3) helping the students to understand the knowledge in polymer physics by experiments, and improving their ability to apply what they have learned; (4) encouraging the students to explore freely by providing experimental conditions and guidance, and thus their abilities in learning, finding and solving problems are improved. The content of this experiment can not only be used in the experimental teaching of Polymer Physics, but also can be extended to other courses including the comprehensive and design experiment, the graduation thesis, and so on.关键词：Polymer physics experiment;Comprehensive and exploratory experiment;Polarizing optical microscope;Polymer spherulite;Teaching reform
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发布时间：2023-01-16
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