Melt reactive

To improve on penetration and heat resistance (properties normally in opposition when formulating hot melts), reactive hot melt systems are being developed. Moisture curing urethanes have already gained wide acceptance in a number of wood and automotive applications. UV cure is slowly gaining acceptance in PSA, labeling, and other markets. 

Solvent additives to the melt (Table 3) fall into two categories extractive and reactive. The extractive solvents (decane, perchloroethane, o-dichlorobenzene, and pyrrolidine) had negligible effect on solubility, possibly due to the preferential wetting of the coal by the solvent and exclusion of the ZnCl2 melt. Reactive solvents (anthracene oil, indoline, cyclohexanol, and tetralin) all incorporated strongly. Donor solvents, tetralin and indoline, increase the "corrected solubility, whereas anthracene oil and cyclohexanol have negligible effect. 

Polyamides It is very difficult to incorporate additives in polyamides because of their melt reactivities. The recent developments for the flame retardancy of polyamides concern mainly the inclusion of nanoparticles, discussed in Section 24.5.3. 

The general paucity of FR polyamides reflects their high melt reactivities and hence poor potential flame retardant additive compatibilities. The only additive currently marketed as a potential flame retardant for polyamide fibres is Clarianf s Exolit OP930/935, which is based on a fine particulate (Dj(, 2-3pm), aluminium diethyl phosphinate. This phosphinate may be used alone or combined with melamine polyphosphate, although in bulk polymers total levels of 15wt% or so are required for acceptable levels of flame retardancy. To date it is not known whether commercially successful PA6 and PA6.6 fibres based on this agent are available. 

Sarla, R.M. Schneidersmaim, E.O. (1960) Fused salt electrolytic cell for producing high-melting reactive metals, such as tantalum. US Patent 2,957,816. 

Diblock copolymers are known to be the most effective compatibilizers for improving the interfacial interactions between two polymers that are immiscible. This is particularly interesting for iPP, since its lack of functionality and the poor compatibility between iPP and other materials have imposed limitations for iPP applications in many areas, including polymer blends and composites. The synthesis of iPP with terminal functional groups (OH, NH2, etc.) offers a good opportunity to carry out chain extensions through simple coupling reactions with suitable polymers. These may be carried out in solution or in the polymer melt. Reactive extrusion of two chain-end reactive polymers... 

The main adhesives for bonding plastics to rubbers include cyanoacrylates, two-part urethanes, two-part epoxies, hot melt reactive urethane prepolymers, heat reactive contact cements and silane treatments. 

Solvent-based Waterborne Hot melt Reactive rstem... 

Rear parcel shelves Hot-melts, reactive hot-melt polyurethanes (RHMU)... 

Keywords Additives Aliphatic Aliphatic isocyanates Amine-isocyanate reaction Aromatic isocyanates Blocked isocyanates Chain extenders Construction (application in) Glass transition temperature Hydroxyl-isocyanate reactions Hot melt reactive PU Isocyanates MDl Moisture curing PU One-component PU Packaging (application in) Plastic and composites (application in) Polyester Polyether polyols Polyisocyanates Sealants Silane PU hybrids TDI Testing of PU adhesives testing of PU sealants Testing standards TPU thermoplastic PU Transportation (application in) Two-component PU Water-borne PU... 

Fina A, Monticelli O, Camino G (2010) POSS-based hybrids by melt/reactive blending. J Mater Chem 20(42) 9297-9305. doi I0.1039/c0jm00480d... 

Extrusion, melting, reactive extrusion, viscosity, energy dissipation, power consumption. 

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