Cross-linking reactions with

The rheology of hydroxypropylguar is greatly complicated by the cross-linking reactions with titanium ions. A study to better understand the rheology of the reaction of hydroxypropylguar with titanium chelates and how the rheology depends on the residence time, shear history, and chemical... 

Cell link is based on the chemistry of dialdehydes and their cross-linking reaction with amino-groups of the protein chains. 

Reetz and Giebel 62) anchored sulfonylated poly(propylene imine) dendrimers by a cross-linking reaction with Sc(OTf)3, resulting in a non-porous material... 

The approach of intramolecular cross-linking was further extended to temperature-sensitive polymers. PVME nanogels were obtained by irradiation of dilute PVME solutions by a pulsed electron beam [41], The Mw of these nanogels is independent of the radiation dose (above 2 kGy). The phase transition temperature Tc of PVME is slightly affected by the cross-linking reaction. With increasing radiation... 

Infrared and functional group analyses showed the presence of hydroxyl end groups in the products. In addition, the results of chain extension and cross-linking reactions with diisocyanates (vide infra) confirmed the presence of two terminal hydroxyl groups. 

On the other hand, if the cross-link density is low (the length of the chains between cross-links is large) and the mobility of the chains is high, the cross-linked material is called an elastomer. An example of a typical elastomer is cw-l,4-polyisoprene (natural rubber), which, by means of a cross-linking reaction with sulfur (vulcanization), gives rise to a network structure (see Fig. 1.4). 

Figure 1.4 (a) cis-1,4-Polyisoprene (natural rubber), (b) Cross-linking reaction with sulfur (vulcanization). 

To fix the adsorbed PVFA-co-PVAm layers irreversibly, cross-linking reactions with bifunctional or multifunctional reagents were carried out on the surface of solid PVFA-co-PVAm/hybrid particles. The cross-linking reactions were performed as two-step synthesis. In the first step PVFA-co-PVAm was... 

If, however, quantitation via gel disruption is foreseen, it is advisable to replace the Bis cross-linking reaction with another one that yields more easily solubilizable gels. Ethylenediacrylate is used for this purpose [253]. Dissolution can be done either by the action of concentrated NH4OH [254] or by piperidine-alcoholic hyamine [253] (9 1). In the latter case gels are dissolved by incubation at 37°C for 3-4 h. Dissolution can be accelerated by addition of another portion of piperidine. 

Other problems are associated with this approach, such as removal of excess chemicals after cross-linking, reactions with large wood cross sections, and drying the wood before reaction. It is, however, an interesting approach that has had very little research effort. 

Maleic anhydride is unsaturated. Its reaction with diethylene glycol leads to a prepolymer with residual double bonds on the main chain. These participate in cross-linking reactions with styrene during initiation with benzoyl peroxide. The result is a network polymer. 

As may be expected, the heat of reaction is derived mainly from the cross-linking reaction with DICY. This concentration dependence is still very prounounced at the B-stage level (Figure 3). 

A-PEO-A V-PDMS-V Cross-linking reaction with PD5 Copolymerization of hydrophilic macro-cross-linker with hydrophobic monomer DS in MeOH and hexane, DSC, TGA 87... 

Copolymers of vinylidine fluoride with hexafluoropropylene are prepared in aqueous dispersions using persulfate initiators. Hexafluoropropylene does not homopolymerize but it does copolymerize. This means that its content in the copolymer cannot exceed 50%. Preferred compositions appear to contain about 80% of vinylidine fluoride. The cross-linking reactions with diamines are not completely understood. It is believed that the reaction takes place in two steps [285, 286]. In the first one, a dehydrofluorination occurs ... 

Discuss the chemistry of epoxy resins based on diglycidyl ethers of Bisphenol A, their preparations, and cross-linking reactions with amines, dianhydrides, and dicyanodiamide. 

Fig. 3. Chemistry of Secondary and Primary Amine Cross-linking Reactions with Epoxies...

Proteic materials used in traditional tempera painting, for instance, are subject to condensation and cross-linking reactions with other components such as lipids. Gas chromatography-mass spectrometry (GC-MS) investigations have shown that the oxidative degradation of amino acids such as cysteine, serine, and phenylalanine leads to the formation of amino malonic acid. The latter compound has been identified via the analysis of aged paint samples [7]. Other modifications are caused by the pH variation of the paint surface that contributes to the hydrolysis of peptide bonds and the partial dehydration of serine and threonine. 

Vinyl acetal polymers can be formulated with other thermoplastic polymers and with a variety of multifunctional cross-linkers. Examples of polymers that are at least partially compatible with PVF or PVB resins include some types of polyurethanes, some types of celluloses, epoxies, isocyanates, phenolics, silicones, unsaturated polyesters, and melamine- and urea-formaldehyde polymers (19-21). Although vinyl acetal polymers are thermoplastic, hydroxyl groups permit cross-linking reactions with a variety of thermosetting resins, for example. 

Reaction with an amino-propyl derivative of glass or hornblende with glutaraldehyde cross-linking reaction with titanium(iv) oxide coated with polymerized, diazotized 1,3-diaminobenzene Reaction with agarose activated with 4-benzoquinone Reaction with agarose cyclic imidocarbonate... 

In Figure 5.17 is shown an amidoximation of CMS-co-poly(AN) (functionalization of CMS through grafting and cross-linking reactions with AN). In this reaction CMS-co-poly(AN) synthesized was treated with hydroxylamine for the conversion of single —C=N function to —CH=NOH moiety [101]. 

The presence of the C=C in unsaturated fatty acids is employed as the reaction sites in the formation of cross-linking. The networked structure can be achieved by a functional reaction of the C=C to enable use in high-molecular-weight products. The properties of the epoxidized resin-based composites are reliant on the extent of cross-linking reaction with the materials. The higher the cross-link density, the better is the mechanical and thermal properties. 

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