Fabrication and cross-linking

The peroxide decomposes at elevated temperatures to give free radicals, which then abstract a hydrogen atom from the methyl group. The radicals formed then combine to form a hydrocarbon linkage. Results obtained by reacting model systems with benzoyl peroxide and analysing the reaction products are consistent with this type of mechanism.  

Rubbers containing traces of vinyl groups can be cross-linked by weaker peroxide catalysts, the reaction involving a vinyl group. It is, however, unlikely that vinyl-to-vinyl linking occurs. Where there is a high vinyl content (4-5% molar) it is possible to vulcanise with sulphur. 

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Thus, if the fabric is flat and smooth, it will tumble dry in that configuration. On the other hand, if the fabric is cross-linked in a creased condition, as in a pleated skirt, the original pleated skirt configuration should return on laundering and tumble drying. 

Some polymer deterioration reactions occur without loss in molecular weight. These include a wide variety of reactions where free radicals (most typical) or ions are formed and cross-linking or other nonchain session reaction occurs. Cross-linking discourages chain and segmental chain movement. At times this cross-link is desired such as in permanent press fabric and in elastomeric materials. Often the cross-links bring about an increased brittleness beyond that desired. 

Collagen sponges with microporous structures from tilapia were fabricated reconstituted collagen fibrils using freeze-drying and cross-linked by DHT treatment or additional treatment with WSC treatment. The pellet implantation tests into the paravertebral muscle of rabbits demonstrated that tilapia collagen caused rare inflammatory responses at 1- and... 

Polymerization of methyl methacrylate monomer with cobalt-60 as source of y-rays, Free radical formation is involved in both cross-linking and polymerization reactions This technique is also being applied in the textile finishing field for grafting and cross-linking fibers with chemical agents for durable-press fabrics. 

The use of insoluble, highly cross-linked anisotropic networks created by the polymerisation of photoreactive monomers, eliminates the problem of crystallisation, at least for organic materials, since polymer networks are macromole-cular structures incapable of crystallising, see Chapter 6. Furthermore, the fabrication of multilayer devices would be facilitated by the use of a cross-linked stable HTL next to the anode on the solid substrate surface, onto which subsequent layers can be deposited by vapour deposition. Multilayer OLEDs are intrinsically more stable than monolayer devices due to a better balance of charge-carriers and concentration of the charged species away from the electrodes. The synthesis and cross-linking of a suitable aromatic triarylamine derivative with a polymerisable oxetane group at each end of the molecule for use as a HTL has been reported recently, ... 

Kulkami et al.94 subjected cotton-PAN graft copolymer to alkaline hydrolysis, methylolated the resulting product at pH 9.5-10 with formaldehyde for 24 h and cross-linked the polymer in an acidic medium at 150°C in the presence of MgC for 5 min. This treatment increased the wrinkling resistance of the cotton fabric appreciably. No effect, however, was observed if the grafted chains were cross-linked by 1,4-divinylbenzene simultaneously with grafting. 

CNC SOFT C-2-U is a synthetic softener for use on fabrics of all constructions where a soft, smooth, silky hand is desired. It is a fine all-purpose fiber lubricant and softener and is particularly recommended for use in combination with thermosetting resins and cross-linking agents to produce a smooth hand and also to minimize tearing and tensile strength loss and improve resistance to abrasion. 

Various forms of chitin-based products are available for medical applications, such as finely divided powder, nonwoven fabrics, porous beads, lyophilized soft fleeces or gels, gauges, laminated sheets, and transparent films. Water-soluble derivatives of chitin in isotonic saline can be administered intramuscularly or intravenously. Certainly, there is considerable biochemical evidence linking NAG with the metabolism of the hexamines, which are assumed to originate and cross-link wound collagen. 

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