Preparation and Performance of (Hydroxy Modified) Poly(p-phenylene-2,6-benzobisimidazole) Resin and Fiber

2013 ◽  
Vol 699 ◽  
pp. 96-102 ◽  
Author(s):  
Ning Ren Jin ◽  
Biao He ◽  
De Ming Zhao ◽  
Jian Ting Zhang ◽  
Xing Wei
Keyword(s):  
Terephthalic Acid ◽  
Monomer Concentration ◽  
Process Conditions ◽  
Polymerization Time ◽  
Preparation Methods ◽  
And Performance

Novel preparation methods for preparing (hydroxy modified) PBI monofilament fiber and PBI resin are investigated and developed by the co-polycondensation of new AA-monomer 1,2,4,5-tetraaminobenzene tetrahydrochloride (TAB•4HCl) respectively with BB type monomers 2,5-dihydroxyterephthalic acid (2,5-DHTA), hydroxyterephthalic acid (HTA) and terephthalic acid (TPA). Effects of process conditions (monomer concentration, P2O5content, temperature and polymerization time) on polymerization and fiber spinnability are studied systematically.

scholarly journals Current overview of carbon fiber: Toward green sustainable raw materials

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7234-7259
Author(s):  
Yongjian Xu ◽  
Yan Liu ◽  
Shenglin Chen ◽  
Yonghao Ni
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Melt Spinning ◽  
Raw Materials ◽  
Future Research ◽  
Process Conditions ◽  
Preparation Methods ◽  
Advantages And Disadvantages ◽  
Solution Spinning ◽  
And Performance

Lignin, as a potential precursor of carbon fiber, has the characteristics of abundant reserves, renewable and high carbon content, and its application in the preparation of carbon fibers has substantial cost advantages if some important processing and quality hurdles can be overcome. This paper reviews the preparation process of lignin-based carbon fibers, and moreover, describes the characteristics of carbon fiber prepared by different precursors compared with the presently used precursors. Three preparation methods for lignin-based carbon fibers are introduced: melt spinning, solution spinning, and electrospinning. The applicability, advantages, and disadvantages of the three preparation methods are analyzed from the aspects of process conditions and performance characteristics. Possible directions for future research are considered, with the goal of providing a reference for further study of lignin-based carbon fibers.

Nanocrystals: The Preparation, Precise Control and Application Toward the Pharmaceutics and Food Industry

2018 ◽  
Vol 24 (21) ◽  
pp. 2425-2431 ◽  
Author(s):  
Cao Wu ◽  
Zhou Chen ◽  
Ya Hu ◽  
Zhiyuan Rao ◽  
Wangping Wu ◽  
...  
Keyword(s):  
Food Industry ◽  
Chemical Properties ◽  
Preparation Methods ◽  
Precise Control ◽  
Significant Process ◽  
Technology Applications ◽  
And Performance ◽  
Physical And Chemical ◽  
Analytical Technology ◽  
And Chemical Properties

Crystallization is a significant process employed to produce a wide variety of materials in pharmaceutical and food area. The control of crystal dimension, crystallinity, and shape is very important because they will affect the subsequent filtration, drying and grinding performance as well as the physical and chemical properties of the material. This review summarizes the special features of crystallization technology and the preparation methods of nanocrystals, and discusses analytical technology which is used to control crystal quality and performance. The crystallization technology applications in pharmaceutics and foods are also outlined. These illustrated examples further help us to gain a better understanding of the crystallization technology for pharmaceutics and foods.

Polymerization of n-butyl methylacrylate using bis(β- ketoamino)nickel(II)/MAO catalytic systems

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaohui He ◽  
Yiwang Chen ◽  
Yongming Liu ◽  
Muqing Chen ◽  
Shuxian Yu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Temperature ◽  
Moderate Activity ◽  
Polymerization Time ◽  
Catalytic Systems ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Broad Molecular Weight Distribution ◽  
C Nmr

AbstractThe polymerizations of n-butyl methylacrylate (nBMA) were carried out using bis(β-ketoamino)nickel(II) complexes (Ni[CH3C(O)CHC(NR)CH3]2: R = phenyl, 1; R = naphthyl, 2) in combination with methylaluminoxane (MAO) in toluene. The effect of parameters such as polymerization temperature, Al/Ni molar ratios, polymerization time, and monomer concentration, on catalytic polymerization activity and polymer molecular weights, were examined in detail. Both of the nickel(II) catalytic systems exhibited moderate activity, and produced P(nBMA) with high molecular weight and relatively broad molecular weight distribution (Mw/Mn=2.0~3.0. The obtained polymer has been characterized by means of FTIR, 1H NMR, 13C NMR, DSC, and WAXD technique and was confirmed to be syndio-rich stereospecific P(nBMA).

scholarly journals Rocess Design of Fiber Reinforced Magnesium Matrix Composites

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Ding Hualun
Keyword(s):  
Composite Materials ◽  
Matrix Composites ◽  
Deposition Method ◽  
Fiber Reinforced ◽  
Casting Method ◽  
Magnesium Matrix ◽  
Preparation Methods ◽  
Magnesium Matrix Composites ◽  
The Matrix ◽  
And Performance

This paper chooses magnesium as the matrix of composite materials, selects carbon fi ber as reinforcement, anddesigns the composite scheme according to the structure and performance of Mg-based composites. The performancecharacteristics and application prospect of fiber-reinforced magnesium matrix composites are introduced. Wait. Inthis paper, the process of preparing carbon fi ber magnesium matrix composites by compression casting method andspray deposition method is designed. The process fl ow chart of these two design schemes is determined by analyzingthe principle of these two kinds of preparation methods, and the specifi c problems of the process are analyzed andsummarized.

scholarly journals A critical review on the development and performance of polymer/graphene nanocomposites

2018 ◽  
Vol 25 (6) ◽  
pp. 1059-1073 ◽  
Author(s):  
Weifeng Chen ◽  
Hu Weimin ◽  
Dejiang Li ◽  
Shaona Chen ◽  
Zhongxu Dai
Keyword(s):  
Polymer Nanocomposites ◽  
Electronic Conductivity ◽  
Future Research ◽  
Preparation Methods ◽  
Graphene Nanocomposites ◽  
Advantages And Disadvantages ◽  
Solution Blending ◽  
Potential Applications ◽  
New Type ◽  
And Performance

AbstractGraphene (graphene) is a new type of two-dimensional inorganic nanomaterial developed in recent years. It can be used as an ideal inorganic nanofiller for the preparation of polymer nanocomposites because of its high mechanical strength, excellent electrical conductivity and plentiful availability (from graphite). In this review, the preparation methods of graphene/polymer nanocomposites, including solution blending, melt blending and in situ polymerization, are introduced in order to study the relationship between these methods and the final characteristics and properties. Each method has an influence on the final characteristics and properties of the nanocomposites. The advantages and disadvantages of these methods are discussed. In addition, a variety of nanocomposites with different properties, such as mechanical properties, electronic conductivity, thermal conductivity and thermal properties, are summarized comprehensively. The potential applications of these nanocomposites in conductive materials, electromagnetic shielding materials, photocatalytic materials and so on, are briefly presented. This review demonstrates that polymer/graphene nanocomposites exhibit superior comprehensive performance and will be applied in the fields of new materials and novel devices. Future research directions of the nanocomposites are also presented.

Preparation and Performance of Porous Membrane Materials Using the Sol-Gel Method

2010 ◽  
Vol 33 ◽  
pp. 251-253
Author(s):  
Peng Zhang ◽  
Gang Chen ◽  
Bin Guo ◽  
Shu Kang Cheng
Keyword(s):  
Sol Gel ◽  
Porous Membrane ◽  
Silica Particles ◽  
High Tech ◽  
Experimental Conditions ◽  
Preparation Methods ◽  
Gel Method ◽  
Membrane Materials ◽  
Sol Gel Method ◽  
And Performance

Porous membrane materials have the universal use, so it is widely considered as one of the most promising high-tech. Different membranes have different preparation methods. In this paper, the sol-gel method was applied to prepare silica particles using ammonia as catalyst of TEOS hydrolysis, then silica particles were mixed with polyethylene, and finally silica particles were dissolved with hydrofluoric acid, leaving holes, the porous materials were obtained. The results show that: (1) In this experimental conditions, the size of silica particles are closely related to the water content of the system. (2) The size of silica particles affects the agglomeration of particles. The size of silica particles are smaller, the agglomeration is more obvious. (3) As the content of PE increases, the porosity of the samples decreases continuously; in theory, when the content of silica is low, the hole will be greater.

Study of the Structure and Oxygen Permeability of Cellulose Packaging Films from NMMO-Solutions

2011 ◽  
Vol 380 ◽  
pp. 148-151
Author(s):  
Pei Fang Cheng ◽  
Jian Qing Wang ◽  
Wen Ming Ren
Keyword(s):  
Fruits And Vegetables ◽  
Oxygen Permeability ◽  
Processing Parameters ◽  
High Oxygen ◽  
Raw Material ◽  
Coagulation Bath ◽  
Process Conditions ◽  
Packaging Films ◽  
Cellulose Films ◽  
And Performance

This paper is concerned with the preparation of cellulose packaging films with high oxygen permeability. The films were prepared from cotton pulp and wood pulp by the cast-wiped method using N-methymorpholine-N-oxide (NMMO) as a solvent. The effects of processing parameters on the structure and performance of cellulose films were also studied. The results show that for optimum processing of the films cotton pulp was the preferred raw material, the optimum pulp concentration in the casting solution was 5%, and the optimum temperature for the coagulation bath was 40°C. Using the above process conditions resulted in packaging films with high oxygen permeability making them suitable for use in packaging fruits and vegetables.

scholarly journals Al-Based Nano-Sized Composite Energetic Materials (Nano-CEMs): Preparation, Characterization, and Performance

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1039 ◽  
Author(s):  
Weiqiang Pang ◽  
Xuezhong Fan ◽  
Ke Wang ◽  
Yimin Chao ◽  
Huixiang Xu ◽  
...  
Keyword(s):  
Energetic Materials ◽  
Recent Progress ◽  
Functional Materials ◽  
Research Field ◽  
Preparation Methods ◽  
Existing Problems ◽  
And Performance ◽  
Future Work ◽  
Application Prospects

As one of the new types of functional materials, nano-sized composite energetic materials (nano-CEMs) possess many advantages and broad application prospects in the research field of explosives and propellants. The recent progress in the preparation and performance characterization of Al-based nano-CEMs has been reviewed. The preparation methods and properties of Al-based nano-CEMs are emphatically analyzed. Special emphasis is focused on the improved performances of Al-based nano-CEMs, which are different from those of conventional micro-sized composite energetic materials (micro-CEMs), such as thermal decomposition and hazardous properties. The existing problems and challenges for the future work on Al-based nano-CEMs are discussed.

The Design and Testing of a Molten Salt Steam Generator for Solar Application

1988 ◽  
Vol 110 (1) ◽  
pp. 38-44 ◽  
Author(s):  
W. A. Allman ◽  
D. C. Smith ◽  
C. R. Kakarala
Keyword(s):  
Molten Salt ◽  
Steam Generator ◽  
Test Facility ◽  
Process Conditions ◽  
Test Results ◽  
Overall Design ◽  
Central Receiver ◽  
And Performance ◽  
Design And Testing ◽  
Solar Application

This paper describes the design and testing of the Steam Generator Subsystem (SGS) for the Molten Salt Electric Experiment at Sandia Laboratories in Albuquerque, New Mexico. The Molten Salt Electric Experiment (MSEE) has been established at the Department of Energy’s five megawatt thermal Solar Central Receiver Test Facility, to demonstrate the feasibility of the molten salt central receiver concept. The experiment is capable of generating 0.75 megawatts of electric power from solar energy, with the capability of storing seven megawatt-hours of thermal energy. The steam generator subsystem transfers sensible heat from the solar-heated molten nitrate salt to produce steam to drive a conventional turbine. This paper discusses the design requirements dictated by the steam generator application and also reviews the process conditions. Details of each of the SGS components are given, featuring the aspects of the design and performance unique to the solar application. The paper concludes with a summary of the test results confirming the overall design of the subsystem.

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