Phenol-formaldehyde-resorcinol separators

Polyethylene separators Phenol- formaldehyde- resorcinol separators PVC sepa- rators Rubber separators Microfiber glass mat separators Total... 

Polyethylene separators Rubber separators Phenol formaldehyde-resorcinol separators Microporous PVC separators... 

Among the separator varieties described, the phenol-formaldehyde-resorcinol separator (DARAK 2000) [60] as well as the microporous PVC separator [86] have proven effective for this construction. For applications without deep discharges, concessions may be made with the respect to porosity and pore sizes of the separator therefore polyethylene separators or a spe-... 

Polyethylene separators Phenol- Formaldehyde- resorcinol Separators Microporous PVC separators Sintered PVC separators Rubber separators... 

Polyethylene Phenol-separators formaldehyde-resorcinol separators... 

Phenol-Formaldehyde Resin-Resorcinol Separators (DARAK 2000/ 5005) The production process and the principal properties of this system have been described in detail in the section on traction battery separators (see Section 11.2.3.1). The outstanding properties, such as excellent porosity (70%) and resulting very low acid displacement and electrical resistance, come into full effect when applied in open stationary batteries. Due to the good inherent stiffness the backweb may even be reduced to 0.4 mm, reducing acid displacement and electrical resistance to low levels that are not achievable by any other system. Furthermore, the phenolic resin-resorcinol separator neither generates any harmful substances nor is it attacked chemically or by oxidation. The sum of these properties has made it the preferred separator for open stationary batteries. 

Figure 3. Phenol-formaldehyde resin resorcinol separator (SEM)...

Phenol-Formaldehyde Resin Resorcinol Separators (DARAK 2000/5005)... 

The condensation of resorcinol, chloroacetic add, and formaldehyde in alkaline medium gives a bifunctional cation-exchange resin containing —COOH and —OH groups . The condensation of salicylic add with formaldehyde in add medium followed by treatment with phenol in alkaline medium also gives a bifiinctional resin which is suitable for separation and purification of proteins . A bifunctional cation-... 

A particularly interesting system now used extensively in several southern hemisphere countries is the so-called honeymoon fast-setting, separate-application system [66,67]. In this system one of the surfaces to be mated in the joint is spread with a standard synthetic phenol-resorcinol-formaldehyde adhesive plus paraformaldehyde hardener. The second surface is spread with a 50% tannin solution at pH 12. When the two surfaces are... 

In the second approach (120), condensed tannins were purified of co-occur-ring carbohydrates and used as resorcinol replacements in a honeymoon system (116) as described previously in use of wattle tannin adhesives. One surface was spread with a commercial phenol-resorcinol-formaldehyde laminating adhesive, to which additional formaldehyde was added. The other surface was spread with pine bark tannin extract in sodium hydroxide solutions. Bonds meeting the requirements of the American Institute of Timber Construction were also obtained using this approach. It was necessary to remove the carbohydrates, however. Addition of the separated carbohydrates at comparatively low levels (about 10%) resulted in bonds with low wood failure. 

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