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Wettability and surface tension of fillers in thermosets
April 1994
Additivesfor Polymers
of stabilizers has been investiga~d. Ex~rimen~l results showed that both calcium carbonate and talc decreased the photostabilizing efficiencies of all the photostabilizers used in this study in the photo-oxidation of PP composites. An efficiency-decreasing effect of fillers on antioxidant Irganox 1010 and Methylene4426-S was also observed in the thermal oxidation of PP composites. It is proposed that the ef~ciency~e~reasing effect of filler on stabilizers is caused by the abso~tion of stabilizer molecules on the surface of the fillers. (2 refs). Polymer Degradation & StabitiQ, 1994, 43, 225-228
The surface tension of mineral fillers is typically low. Measurements showed values around 50 mN/m for most types; the results obtained with powders and polished quartz rocks agree well. Silanization affects the surface tension in such a way that the desired adhesion characteristics and surface chemistry can be adjusted to different processing properties, wetting properties, and final properties. It remains to be elucidated why, despite similar surface tension and equal filler geometry, different wetting kinetics are observed among resin systems. For the surface tension of resin systems, which are frequently used as binders, values between 32 and 45 mN/m were obtained.
Hexamethylene-N,N’ bis (tertbutyl peroxycarbamate) as cross~inking agent in elastomers The use of hexamethylene-N,N’ bis (tert-butyl peroxycarbamate) (HBTBP) as a crosslinking agent in natural rubber and fluoroelastomers has been examined, and this paper reports the results of the technological evaluation of this crosslinking agent in other elastomers. Using the Monsanto Oscillating Disk Rheometer, it is found that HBTBP will crosslink nitrile rubber, serene-bu~iene rubber, silicone rubber, poly~hloroprene and epicblorohydrin rubber. However, HBTBP is not found suitable as a crosslinker for chlorosulphonated polyethylene and ethylene-propylene diene terpolymer . (7 refs). Iraniun J. of Polymer Science Technology, 1994, 3, (Jan), 48-59
kinetics of the investig~~ powders.
&
According to theories concerning the surface energy, complete wetting of most varieties of powders is thus guaranteed. Limitations only concern combinations with calcium carbonate and fillers coated with methacrylosilanes. These materials facilitate processing. Fracture images of the composite materials, on the other hand, point to insufficient interface adhesion to the matrix. Fillers with a noticeably higher surface tension compared to the resin create dispersion problems as they are mixed with the resin, which partially offsets the advantage of high interactive forces, Kunststoffe Plast Europe, 1994, 84, (Jan) 18-20
nettability and surface tension of fillers in thermosets Wetting experiments according to the capillary-rise method are well suited to determinations of the surface tension of powderized fillers. Owing to their reproducibility, such experiments also lend themselves to quality control of powderized fillers. Wetting experiments involving resin systems point to differences in the wetting 10
Cytec Industries acquires Zeneca HALS technology Cytec Industries, West Paterson, NJ (formerly part of American Cyanamid) has acquired the Topanex UV-stabilizer technology and business of Zeneca
@1994Elsevier Science Ltd
Additivesfor Polymers
of stabilizers has been investiga~d. Ex~rimen~l results showed that both calcium carbonate and talc decreased the photostabilizing efficiencies of all the photostabilizers used in this study in the photo-oxidation of PP composites. An efficiency-decreasing effect of fillers on antioxidant Irganox 1010 and Methylene4426-S was also observed in the thermal oxidation of PP composites. It is proposed that the ef~ciency~e~reasing effect of filler on stabilizers is caused by the abso~tion of stabilizer molecules on the surface of the fillers. (2 refs). Polymer Degradation & StabitiQ, 1994, 43, 225-228
The surface tension of mineral fillers is typically low. Measurements showed values around 50 mN/m for most types; the results obtained with powders and polished quartz rocks agree well. Silanization affects the surface tension in such a way that the desired adhesion characteristics and surface chemistry can be adjusted to different processing properties, wetting properties, and final properties. It remains to be elucidated why, despite similar surface tension and equal filler geometry, different wetting kinetics are observed among resin systems. For the surface tension of resin systems, which are frequently used as binders, values between 32 and 45 mN/m were obtained.
Hexamethylene-N,N’ bis (tertbutyl peroxycarbamate) as cross~inking agent in elastomers The use of hexamethylene-N,N’ bis (tert-butyl peroxycarbamate) (HBTBP) as a crosslinking agent in natural rubber and fluoroelastomers has been examined, and this paper reports the results of the technological evaluation of this crosslinking agent in other elastomers. Using the Monsanto Oscillating Disk Rheometer, it is found that HBTBP will crosslink nitrile rubber, serene-bu~iene rubber, silicone rubber, poly~hloroprene and epicblorohydrin rubber. However, HBTBP is not found suitable as a crosslinker for chlorosulphonated polyethylene and ethylene-propylene diene terpolymer . (7 refs). Iraniun J. of Polymer Science Technology, 1994, 3, (Jan), 48-59
kinetics of the investig~~ powders.
&
According to theories concerning the surface energy, complete wetting of most varieties of powders is thus guaranteed. Limitations only concern combinations with calcium carbonate and fillers coated with methacrylosilanes. These materials facilitate processing. Fracture images of the composite materials, on the other hand, point to insufficient interface adhesion to the matrix. Fillers with a noticeably higher surface tension compared to the resin create dispersion problems as they are mixed with the resin, which partially offsets the advantage of high interactive forces, Kunststoffe Plast Europe, 1994, 84, (Jan) 18-20
nettability and surface tension of fillers in thermosets Wetting experiments according to the capillary-rise method are well suited to determinations of the surface tension of powderized fillers. Owing to their reproducibility, such experiments also lend themselves to quality control of powderized fillers. Wetting experiments involving resin systems point to differences in the wetting 10
Cytec Industries acquires Zeneca HALS technology Cytec Industries, West Paterson, NJ (formerly part of American Cyanamid) has acquired the Topanex UV-stabilizer technology and business of Zeneca
@1994Elsevier Science Ltd