Resin stability

The substitution of water-borne versions of these primers is increasing as environmental restrictions on the use of organic solvents become stricter. These are generally aqueous emulsions of epoxy novolac or phenolic based resins stabilized by surfactants [34]. Non-ionic surfactants are preferred, as they are non-hygroscopic in the dried primer films. Hygroscopic ionic surfactants could result in excessive water absorption by the primer film in service. 

Uses. Diluent for epoxy resins stabilizer of chlorinated organic compounds... 

Uses. Reactive diluent for epoxy resins stabilizer for organic compounds chemical intermediate for synthesis of ethers and esters... 

The first step in processing is usually powder mixing in a high speed, intensive mixer. PVC resin, stabilizers, plasticizers, lubricants, processing aids, fillers, and pigments are added to the powder blend for distributive mixing. 

Synthetic Resin Industry Liquid resin stabilizer, molding powder, carbohydrate resins, vulcanization of vinyl resins and copolymers, aniline shellac resins... 

In order to incorporate both tendencies, Lazare, Sundheim, and Gregor developed an improved model, where the elastic and electrostatic interactions were included. In this model, the resin was regarded as a set of charged planar capacitors, with the plates interconnected by elastic springs (Figure 7.24) [126], The balance between forces is attained when the elastic forces provided by the polymeric resin stabilize the dissolution propensity. 

Plenlizer [Ajinomoto]. TM for a line of plastic resin stabilizers. 

Roffael (15) measured formaldehyde emissions from a phenolic particleboard using the WKI-Method which involves suspending small samples over 50 cm of distilled water in tightly closed polyethylene bottles and measuring formaldehyde levels in the water after varying times. Temperatures were maintained at 42 C. This work indicated that formaldehyde release from the phenolic particleboards ceased after a relatively short reaction period (approximately 96 hours). This finding is consistent with the resin stability considerations discussed previously under theoretical considerations. 

The question of the contribution of UF resin hydrolysis to board emission is not a trivial one. If resin hydrolysis contributes significantly to emission, then, in principle, the board would retain the potential to emit during its useful life, in contrast to the situation if all the emission results from free formaldehyde. In the former case, efforts to minimize emission must be directed toward resin stabilization and/or to ensuring that incorporated formaldehyde scavengers retain their effectiveness at low formaldehyde activities for the board s entire useful life. Another consequence of continued resin hydrolysis is possible limits on the durability of UF bonded products in this case improvement may be expected from more stable resins. 

PVC is inherently the most heat-sensitive of the major commercial thermoplastic resins. Stabilization consists primarily of a stabilizing action on labile chlorine atoms in the PVC resin in order to prevent dehydrohalogenation and secondly in the neutralization of HCl by incorporation of bases [138]. Worldwide consumption of heat stabilizers is slightly above 300 thousands of metric tonnes per annum [139] (Table 16). 

The widespread application of U-F resins has meant understanding the mechanism of the degradation process is important if an improvement in resin stability is to be obtained [16]. Therefore the way in which U-F resins change when they undergo hydrolysis was examined. The resins have been described previously [13]. There are a number of possible mechanisms which involved the hydrolysis of the moieties in the U-F resins. A typical degraded resin is shown in Fig. 15.2.12. 

Figure S. Isothermal DSC measurements at the epoxy diacrylate resin stabilized with HALS-1 at various temperatures.

AnrameL [Auralux] Melamine-formaldehyde resin stabilizing resin fw textiles. 

Anion exchange was investigated for application as a small-scale, primary extraction process to recover plutonium directly from dissolved irradiated uranium in 8N HNO3. A 50-kg U/day pilot plant was operated (76). Even with two cycles of ion exchange the fission product activity with the plutonium was undesirably high. Resin stability is another potential problem which was not resolved fully. 

Silicone oil can be emulsified and stabilized via the use of Pemulen resins. The resins stabilize emulsions via electrostatic stabilization. This relieves the constraint of seeking an appropriate surfactant emulsifier. 

A main problem of DNQ/novolac resist solutions is their instability, and several stabilizing additives for diazo compounds are therefore added to the formulation to prevent this problem. Some of these additives include dyes and resin stabilizers. 

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