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ABS, additives

MBS materials vary considerably in their tendency to cause stress-whitening in PVC and in their effect on impact strength. They are generally considered to lead to better aging than ABS additives but are marginally more expensive. [Pg.342]

Tensile tests that include yield stress and elongation at break usually decrease with the ABS addition of the PC value to that of the ABS showing a minima at intermediate composition range. PC and ABS were found to be compatible. At high PC contents, synergistic effects were found in the impact strengths with pronounced extrema at maximum stress. Fractography was used to elucidate the deformation mechanisms. [Pg.170]

Figure 4.8 Creep for two equal loading steps. Additional instantaneous strain CE = AB. Additional total strain at (q + At) JK = GH... Figure 4.8 Creep for two equal loading steps. Additional instantaneous strain CE = AB. Additional total strain at (q + At) JK = GH...
A few ab initio calculations are the main source of our current, very meagre knowledge of non-additive contributions to the short-range energy [91], It is unclear whether the short-range non-additivity is more or less important than the long-range, dispersion non-additivity in the rare-gas solids [28, 92],... [Pg.200]

In recent years, these methods have been greatly expanded and have reached a degree of reliability where they now offer some of the most accurate tools for studying excited and ionized states. In particular, the use of time-dependent variational principles have allowed the much more rigorous development of equations for energy differences and nonlinear response properties [81]. In addition, the extension of the EOM theory to include coupled-cluster reference fiuictioiis [ ] now allows one to compute excitation and ionization energies using some of the most accurate ab initio tools. [Pg.2188]

As shown in section C2.6.6.2, hard-sphere suspensions already show a rich phase behaviour. This is even more the case when binary mixtures of hard spheres are considered. First, we will mention tire case of moderate size ratios, around 0.6. At low concentrations tliese fonn a mixed fluid phase. On increasing tire overall concentration of mixtures, however, binary crystals of type AB2 and AB were observed (where A represents tire larger spheres), in addition to pure A or B crystals [105, 106]. An example of an AB2 stmcture is shown in figure C2.6.11. Computer simulations confinned tire tliennodynamic stability of tire stmctures tliat were observed [107, 1081. [Pg.2689]

Fig. 2.7 The addition of a 3d orbital to 2p gives a distorted orbital. (Figure adapted from Hehre WJ, L Radom, p i)R Sdileycr and ] A Hehre 1986. Ab initio Molecular Orbital Theory. New York, Wiley.)... Fig. 2.7 The addition of a 3d orbital to 2p gives a distorted orbital. (Figure adapted from Hehre WJ, L Radom, p i)R Sdileycr and ] A Hehre 1986. Ab initio Molecular Orbital Theory. New York, Wiley.)...
Thionyl chloride (11.5g, 96.4 mmol) was added to 2-nitrophenylacetic acid (8.72g, 48.2mmol) and the suspension was warmed to 50°C and stirred until gas evolution was complete. The resulting solution was concentrated in vacuo and the residue dissolved in CHjClj (30 ml). This solution was added dropwise to a stirred solution of Meldrum s acid (6.94 g, 48.2 mmol) in CH2CI2 (200 ml) under nitrogen at 0 C. The solution was stirred at 0" C for 1 h after the addition was complete and then kept at room temperature for an additional hour. The reaction solution was then worked up by successively washing with dil. HC1, water and brine and dried (MgSOJ. The dried solution was concentrated in vacuo and abs. ethanol (200 ml) was added to the residue. The mixture was... [Pg.17]

Sodium metal (0.23 g, 10 mmol) was dissolved in abs. EtOH (30 ml), Gramine (1.74g, 10 mmol) and diethyl formamidoinalonate (2.03 g, 10 mmol) were added, followed by slow addition of dimethyl sulfate (2.52 g). The solution was allowed to stand at room temperature for 4h, during which a precipitate formed. The mixture was poured into water and the product collected by filtration (99% yield). [Pg.122]

A solution of 6-bromoindole (O.lOmol) in toluene (200 ml) was treated with Pd(PPh3)4 (5mol%) and stirred for 30 min. A solution of 4-fluorophenyl-boronic acid (0.25 M, 0.15 mol) in abs. EtOH was added, followed immediately by sal aq. NaHCOj (10 eq.). The biphasic mixture was refluxed for several hours and then cooled to room temperature. The reaction mixture was poured into sat. aq. NaCl (200 ml) and the layers separated. The aq. layer was extracted with additional EtOAc (200 ml) and the combined organic layers dried (Na2S04), filtered and concentrated in vacuo. The solution was filtered through silica gel using hexane-CHjCl -hexanc for elution and evaporated. Final purification by recrystallization gave the product (19 g, 90%). [Pg.143]

The second step determines the LCAO coefficients by standard methods for matrix diagonalization. In an Extended Hiickel calculation, this results in molecular orbital coefficients and orbital energies. Ab initio and NDO calculations repeat these two steps iteratively because, in addition to the integrals over atomic orbitals, the elements of the energy matrix depend upon the coefficients of the occupied orbitals. HyperChem ends the iterations when the coefficients or the computed energy no longer change the solution is then self-consistent. The method is known as Self-Consistent Field (SCF) calculation. [Pg.44]

In HyperChem, equation (226) is used for calculating the integrated infrared band intensities for the ab initio method and equation (228) is employed for all the semi-empirical methods. All IR lines correspond to transitions from the ground vibrational state to an excited vibrational state that has one additional quantum deposited in a given vibrational mode. [Pg.338]

In this section we turn to a consideration of the experimental side of condensation kinetics. The kind of ab links which have been most extensively studied are ester and amide groups, although numerous additional systems could also be cited. In many of these the carbonyl group is present and is believed to play an important role in stabilizing the actual chemical transition state involved in the reactions. The situation can be represented by the following schematic reaction ... [Pg.282]

Thermodynamic properties such as heats of reaction and heats of formation can be computed mote rehably by ab initio theory than by semiempirical MO methods (55). However, the Hterature of the method appropriate to the study should be carefully checked before a technique is selected. Finally, the role of computer graphics in evaluating quantum mechanical properties should not be overlooked. As seen in Figures 2—6, significant information can be conveyed with stick models or various surfaces with charge properties mapped onto them. Additionally, information about orbitals, such as the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), which ate important sites of reactivity in electrophilic and nucleophilic reactions, can be plotted readily. Figure 7 shows representations of the HOMO and LUMO, respectively, for the antiulcer dmg Zantac. [Pg.163]

The copolymer latex can be used "as is" for blending with other latexes, such as in the preparation of ABS, or the copolymer can be recovered by coagulation. The addition of electrolyte or free2ing will break the latex and allow the polymer to be recovered, washed, and dried. Process refinements have been made to avoid the difficulties of fine particles during recovery (65—67). [Pg.194]


See other pages where ABS, additives is mentioned: [Pg.509]    [Pg.247]    [Pg.86]    [Pg.509]    [Pg.509]    [Pg.140]    [Pg.7882]    [Pg.145]    [Pg.163]    [Pg.19]    [Pg.509]    [Pg.247]    [Pg.86]    [Pg.509]    [Pg.509]    [Pg.140]    [Pg.7882]    [Pg.145]    [Pg.163]    [Pg.19]    [Pg.320]    [Pg.375]    [Pg.195]    [Pg.2210]    [Pg.2295]    [Pg.2878]    [Pg.503]    [Pg.527]    [Pg.532]    [Pg.636]    [Pg.166]    [Pg.94]    [Pg.131]    [Pg.210]    [Pg.214]    [Pg.255]    [Pg.551]    [Pg.636]    [Pg.15]    [Pg.166]    [Pg.186]    [Pg.191]   
See also in sourсe #XX -- [ Pg.348 , Pg.629 ]




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Additional Information Obtained from Semi-empirical and Ab Initio Calculations

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