国内外ABS树脂生产与市场分析预测

简述了2022年国内外ABS树脂的生产技术情况;对ABS树脂的市场供需、价格、进出口及其下游领域的消费情况进行了分析预测;介绍了ABS树脂在工艺改进、专用料、生产设备改进、减排技术、标准制定等方面的一些技术进展情况;提出了发展建议。

AB INITIO STUDY ON THE REACTION OF CH WITH NH3

The mechanism of the reaction of the CH radical with NH3 has been theoretically studied at the MP2/6-31G** level. The calculation results Indicate that the insertion reaction path Is the favourable channel, which is in line with Lin's proposal based on their kinetic experiments. A detailed description of the complicated insertion reaction path is presented.

Defect stability in thorium monocarbide:An ab initio study

The elastic properties and point defects of thorium monocarbide（ThC） have been studied by means of density functional theory based on the projector-augmented-wave method. The calculated electronic and elastic properties of ThC are in good agreement with experimental data and previous theoretical results. Five types of point defects have been considered in our study, including the vacancy defect, interstitial defect, antisite defect, schottky defect, and composition-conserving defect. Among these defects, the carbon vacancy defect has the lowest formation energy of 0.29 eV. The second most stable defect（0.49 eV） is one of composition-conserving defects in which one carbon is removed to another carbon site forming a C2 dimer. In addition, we also discuss several kinds of carbon interstitial defects, and predict that the carbon trimer configuration may be a transition state for a carbon dimer diffusion in Th C.

AB INITIO CONFIGURATION INTERACTION STUDY OF THE ELECTRONIC AND GEOMETRIC STRUCTURE OF MIXED NEUTRAL AND CATIONIC BLi_k（k＝1~7）CLUSTERS

The geometries of mixed neutral and cationic BLik(k=1-7)clusters have ben determined with energy gradient method.The correlation energy is considered with the single-double configuration interaction(CISD).The boron atom B takes the central position in the most stable geometries of all clusters studied except in the neutral BLi3 cluster.The binding energies per atom and the second differences in energies are discussed.

Microwave Study of Recycled ABS Resins

This article provides a review of the research unde rt aken in order to determine the suitability of utilizing microwave technology in the production of Recycled ABS Acrylonitrile Butadiene Styrene resin for mouldin gs. The experimental investigation determined the suitability of the existing re cycled ABS material, the mould material used with respect to performance and lon gevity, potential commercial plant and equipment, end mould compression. Introduction Frequency Characterization of ABS The first step in microwave processing of any material is to locate a frequency band suitable for the mateiial, where it absorbs microwave energy readily. To lo cate this band width, the ABS material was characterized in Variable Frequency M icrowave Ovens operating between the frequenc’y ranges of 2.5 GHz to 6.5 GHz an d 6 GHz to 18 GHz. The variable frequency microwave oven records forward and ref lected powers over regular intervals in the swept frequency range and enables ca lculation of Re flec tan ce=Re fla tan ce forwrd PowerForward Power (1) A low reflectance indicates that the material Forward Power absorbs rela tively higher amount of incident microwave energy. Characterization of the PBS material showed clearly that a frequancy Fig.1 Lower frequency range vs. reflectance of ABS at room te mperatureFig.2 Lower frequency range vs. reflectance of AB S at 80 ℃ 2.5 to 3.5 GHz is the most suitable frequency fo r heating the material. Other alternate frequencies are 12.25 GHz and 15 GHz. Fi g.1. Hazards When ABS is melted a dark fume is omitted, exhaust system was applied, in order to mechanically ventilate and control exposure levels below air borne exposures. The product contains a trace quantity of acrylonitrile, a substance classified by Worksafe Australia as a Category 2 Carcinogen. [TPP115B,+28mm95mm,Y,PZ#] Fig.3 Polypropylene mouldMould design For holding the ABS granules in a single mode cavity, an unfilled p olypropylene mould was designed. A polypropylene lid with a loading arrangement built in the microwave cavity provided pressure to the materinl in the die, duri ng microwave heating. The pressure can be varied with changing weights on the lo ading device and calculating the pressure. Materials Polypropylene has excellent microwave heating properties, a mould was machine to cater for the experimental requirements. Other materials suitable for mould des ign for long term use are quartz and alumina. Quartz being transparent to both m icrowaves and light provides advantages in noncontact optical temperature measur ements. Conclusion The application of microwave heating for the manufacturing of ABS die casts stru ctures has been developed. An experimental results based on the dielectric behav iour illustrate dopent is required to engage dielectric heating. Chemical Compos ition of ABS, Acrylonitrile Butadiene Styrene, the percentage of each compound a s it would have a direct relationship on the dielectric properties of the ABS.

Ab Initio Studies of Radicals HBX(X=H, F, Cl, Br): Molecular Structure,Vibrational Frequencies and Potential Energy

We describe high-level ab initio calculations on the BH_2, HBF, HBCl and HBBr radicals. Molecular structure,vibrational frequencies and potential energy curves of the ground state and the first excited state, which are two Renner-Teller components for a^2Π state at linearity, are studied using the basis sets aug-cc-pVTZ and icMRCI＋Q technique. On the basis of the potential energy curves, a reliable potential energy barrier to dissociation HB＋X（X=F, Cl, Br） fragments and to linearity are given. The ab initio results will add some understanding on the spectrum and the photo-dissociation dynamics of the series of radicals.

Ab initio study of dynamical properties of U-Nb alloy melt

The U-Nb alloy,as a kind of nuclear material with good corrosion resistance and mechanical properties,plays an important role in the nuclear industry.However,the experimental measurements and theoretical calculations of many parameters which are essential in describing the dynamical properties of this alloy melt,including density,diffusivity,and viscosity,have not been carried out yet.The lack of data on the dynamical properties of nuclear materials seriously hinders the high-performance nuclear materials from being developed and applied.In this work,the dynamical properties of the U-Nb alloy melt are systematically studied by means of ab initio molecular dynamics simulations and their corresponding mathematical models are established,thereby being able to rapidly calculate the densities,diffusion coefficients,viscosities,and their activation energies in the whole U-Nb liquid region.This work provides a new idea for investigating the dynamical properties of binary alloy melts,thereby promoting the development of melt research.

Ab Initio Study of the Dynamical Si-O Bond Breaking Event in α-Quartz

The Si-O bond breaking event in the a-quartz at the first triplet （T1） excitation state is studied by using ab initio molecular dynamics （AIMD） and nudged elastic band calculations. A meta-stable non-bridging oxygen hole center and E1 center （NBOHC-E） is observed in the AIMD which consists of a broken Si-O bond with a Si-O distance of 2.54A. By disallowing the re-bonding of the Si and 0 atoms, another defect configuration （lll- Si/V-Si） is obtained and validated to be stable at both ground and excitation states. The NBOHC-E is found to present on the minimal energy pathway of the initial to IlI-Si/V-Si transition, showing that the generating of the NBOHC-E is an important step of the excitation induced structure defect. The energy barriers to produce the NBQHC-E＇ and Ⅲ-Si/V-Si defects are calculated to be 1.19 and 1.28eV, respectively. The electronic structures of the two defects are calculated by the self-consistent GW calculations and the results show a clear electron transition from the bonding orbital to the non-bonding orbital.

AB INITIO STUDY OF LOW-LYING ELECTRONIC STATES OF THE AsH_2 RADICAL

The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly- ing electronic states X ~2B_1,~2A_1,~2B_2 and ~2A_2 of the AsH_2 radical have been calculated at the MRSDCI level with a 3-21G~* basis set.Our calculated geometries,excitation enegies and vibional frequencies for the X ~2B_1 and ~2A_1 states are in good agreement with available experimental data.The electronic transition dipole mo- ments,oscillator strengths for the ~2A_1→X ~2B_1 and ~2A_2→X ~2B_1 transitions,radiative lifetimes for the ~2A_1 and ~2A_2 states are calculated based on the MRSDC^1 wavefunctions,predicting results in reasonable agreement with available experiment.

AB INITIO STUDIES ON THE INTERACTION BETWEEN CH_3OH AND H_2CO

The interaction between CH_3OH and H_2CO has been studied by ab initio method(6-311G basis set).It has been found that there are two possible complexes:(Ⅰ)H-bond Brnsted complex CH_3OH...OCH_2(Ⅱ)Donor scceptor Lewis complex CH_3OH...CH_2P.HF/6-311G stabilization energies for complex(Ⅰ)and complex(Ⅱ)are 25.1 and 17.1 kJ/mol respectively.

AB INITIO STUDY OF 1,2-DITHIOSQUARIC ACID

Result of ab initio SCF calculation of 1,2-dithiosquaric acid (3,4-dihydroxy-3-cyclobutene-1,2-dithione) are reported. The ZZ isomer is found to be the most stable of the three isomers. An isodesmic energy analysis has been carried out at the HF 6-31G*//6-31G* level for the three planar isomers. The three isomers have positive isodesmic energies or small negative ones, suggesting that 1,2-dithiosquaric acid is not aromatic. Vibrational frequencies have also been calculated for the three isomers.

Ab Initio Study on Structural and Magnetic Properties of Ni-Pd and Ni-Pt Linear and Zigzag Nanowires

Employing the accurate frozen-core full-potential projector augmented-wave method,the self-consistentelectronic structure calculations were carried out on pure Ni,Pd,Pt and mixed Ni-Pd and Ni-Pt free-standing linear andzigzag nanowires.The bond lengths for all these systems are generally increased as their structures change from the linearto the zigzag chain.The bond lengths for Ni-Pd and Ni-Pt wires are in between the values of corresponding pure systemand the bond angles around 60° suggesting the possible formation of Ni-Pd and Ni-Pt bimetallic materials.In mixedNi-Pd and Ni-Pt chains,the Ni,Pd,and Pt atoms have quite high local magnetic moments.The calculations suggestthat the magnetic moments in linear nanowires are generally larger than the ones of corresponding zigzag nanowires.Itis found that there is hybridization between Ni 3d and Pd 4d,Ni 3d and Pt 5d states,which may significantly affectstructural stability and magnetism of Ni-Pd and Ni-Pt nanowires.

AB INITIO STUDY ON GAS-PHASE FACTION OF Ca WITH HN_3

The reaction of Ca with HN3 has been investigated theoretically by an ah initio MO methodwith electron correlation being taken into account by second-order MLLER-PLESSET(MP2)perturbation theory Two possible product channels. CaN3+H. CaNH+N2, on the potential energysurfaces(PESs) have been examined and the reaction mechanism discussed. Values of tile HN-NZ,HN3, Ca-N3 and Ca-AH bond dissociation energy are also calculated, which are in good agreement withexperiment

Ground State Structures of Boron-Rich Rhodium Boride: An Ab Initio Study

A new phase of RhB4is predicted based on first-principles calculations. The new phase belongs to the orthorhombic Pnnm space group, named as o-RhB4, and analysis of the calculated enthalpy shows that o-RhB4belongs to the orthorhombic Pnnm space group. The calculated phonon band structure shows that the orthorhombic Pnnm o-RhB4structure is stable at ambient pressure. We expect that the phase transition can be further confirmed by experiments.

Ab Initio Study of NH_3-CH_3OH Neutral and Ionic Clusters

NH3-CH3OH system was studied by ab initio calculations at the Hartree-Fock level using the 6-31Gbasis set. Equilibrium geometries of both of its ionic (type I and II) and neutral clusters are obtained. Different dissociation channels are evaluated for I and II, respectively. The results suggest that when NH3-CH3OH is vertically ionized,CH3O + NH+ are the dominant products via a proton transfer reaction, and accompanying the dissociation of (NH3-CH3OH)+ver to NH3 + + CH3OH, intracluster charge transfer process takes place in the system.

Ab Initio Study on the Reaction of La+ + CH4→La+-CH2 + H2

Ab initio study on the reaction or the ground state (a3F) and excited state (a1D) or La+with methane has been Performed. performed. channel on the singlet and triplet potential energysurface (PES) has been examined and the reaction mechanism are discussed. Comparisons betweensinglet and triplet PESs show that the ex￣ state (aiD) of La+ is more r￣ than its groundstate (a3F) due tO the SPin quantum number conservation with the more stable insertion intermediate for excited state (1D), which is in good agreement with the experiment.

Ab Initio Study of Single-and Double-Electron Capture Processes in Collisions of He^(2+) Ions and Ne Atoms

The single-and double-electron capture(SEC, DEC) processes of He^(2+) ions colliding with Ne atoms are studied by utilizing the full quantum-mechanical molecular-orbital close-coupling method. Total and state-selective SEC and DEC cross sections are presented in the energy region of 2 eV/u to 20 keV/u. Results show that the dominant reaction channel is Ne^(+)(2s2p^(6) ^(2)S) + He^(+)(1s) in the considered energy region due to strong couplings with the initial state Ne(2s^(2)2p^(6)^(1)S) + He^(2+) around the internuclear distance of 4.6 a.u. In our calculations, the SEC cross sections decrease initially and then increase whereby, the minimum point is around 0.38 keV/u with the increase of collision energies. After considering the effects of the electron translation factor(ETF), the SEC cross sections are increased by 15%–25% nearby the energy region of keV/u and agree better with the available results. The DEC cross sections are smaller than those of SEC because of the larger energy gaps and no strong couplings with the initial state. Due to the Demkov-type couplings between DEC channel Ne^(2+)(2s^(2)2p^(4)^(1)S) + He(1s^(2)) and the dominating SEC channel Ne^(+)(2s2p^(6) ^(2)S) + He^(+)(1s), the DEC cross sections increase with increasing impact energies. Good consistency can also be found between the present DEC and the experimental measurements in the overlapping energy region.

Ab initio Study on the Interaction of La (Ⅲ) with Adrenaline

The interaction of La(III) with adrenaline was studied using Ab initio mathod. The geometry of the complex of La (III) with adrenaline was optimized, and the La(III) bonding site in adrenaline was ascertained

Relaxation of 6H-SiC(0001) Surface and Si Adsorption on 6H-SiC(0001):an ab initio Study

First-principles calculations are carried out to study the relaxation of 6H-SiC （0001） surface and chemisorption models of Si adatoms on four high-symmetry adsorption sites. The surface results show that Si-termination is the preferred termination of the 6H-SiC（0001） polar surface and is more stable than the C-terminated 61-1- SiC（0001） polar surface over a wide range of allowed chemical potentials. Four stable atomic configurations （top, bridge, hcp and fcc） are considered, and the adsorption energies and geometries, Mulliken charge population, and partial density of state （PDOS） properties are analyzed. Adsorption energy results show that the top site is the most stable site. The structural properties of Si adsorption on the SiC （0001） surface shows that increasing stability means decreasing bond lengths. Charge populations analysis and PDOS results imply that there is strong interaction between Si adatoms and 6H-SiC （0001） surface.

STUDY ON AB-CROSSLINKED POLYMERS Ⅰ. THE SYNTHESIS AND MECHANICAL PROPERTIES OF AB-CROSSLINKED POLYMERS BASED. ON PU/PS

The AB-crosslinked polymers (i.e. ABCP) with polystyrene as chain A and vinyl group blocked prepolymers of polyurethanes (PU) as chain B were synthesized and studied. The results of dynamic mechanical spectrometry (DMS) show that the compatibility between the components A and B can be improved greatly through chemical crosslinking during the formation of ABCPs. This effect is especially pronounced when short chain prepolymers is chosen as one of the components. It is apparent that the degree of crosslinking between the two components plays a major role in determining their compatibility. Copolymerizafion of styrene with maleic anhydride in chain A can improve the compatibility and broaden the damping temperature range. Mechanical properties of the sythesized ABCPs were also studied.