Self-crosslinking

Mimlmum Film Formation Temperature C 0 Ionic Charge Nonionic pH as packed 3.0 Density Ibs/US gal 8.7 Brookfield Viscosity, cP 50 Performance Properties  

Durability to Washing Excellent Durability to Drycleaning Fair Forms very soft films. Recommended for fabric finishing, especially to improve the abrasion resistance of durable-press fabrics and for pigment dyeing. 

ROHM AND HAAS CO. RHOPLEX Acrylic Emulsions(Continued)  

Durability to Washing Excellent Durability to Drycleaning Good Forms a soft film with excellent low-temperature flexibility. Recommended as a flocking adhesive. Excellent resilience with good solvent resistance. 

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John, G. and Pillai, C.K.S. (1992) Self-crosslinkable monomer from cardanol crosslinked beads of poly(cardanyl acrylate) by suspension polymerization. Makromolekulare Chemie Rapid Communications, 13, 255—259. 

Table I. Self-Crosslinkable Solution Polymer Performance ...

Diol Two Component Cure. Amide/blocked aldehyde systems show high reactivity with 1,2 or 1,3 diols and give thermodynamically favored cyclic acetals. As mentioned above, even monomers which self-crosslink poorly because they cannot cycllze to the hemlamidal (I.e., 13, 14) will react efficiently to form crosslinked bis-cycloacetals H In the presence of a tetraol (or, to Impart organic solubility, a blocked tetraol, 15, Scheme 3). 

Mecerreyes D, Lee V, Hawker CJ, Hedrick JL, Wursch A, VoUcsen W, Magbitang T, Huang E, Miller RD (2001) A novel approach to functionalized nanoparticles self-crosslinking of macromolecules in ultradilute solution. Adv Mater 13 204—208... 

The soluble hydroxymethyl compounds can be chemically modified, before crosslinking, by reaction with monofunctional compounds (e.g., by esterification or ether formation). The properties of the starting materials as well as the crosslinked end products can thereby be substantially altered. For example, by partial etherification with butanol the hydroxymethyl compounds, originally soluble only in polar solvents, become soluble also in nonpolar solvents (toluene), without losing their ability to undergo self-crosslinking. 

The simple self-crosslinking treatment also crosslinks GAG chains to collagen [30]. The reaction kinetics are outlined in Fig. 2. The mechanism probably involves condensation of amino groups of collagen with carboxylic groups of glucuronic acid residues on the repeat unit of chondroitin 6-sulfate. Dehydra-... 

Fig. 47 Rheographs obtained from self-crosslinkable CR/XNBR blends of different composition at 180°C. Arrows indicate the development of torque after addition of 10 phr organoclay...

Gum (Self-Crosslnked) Filled (Self-Crosslinked) 1 Gum (Sulphur-Crosslinked)... 

Fig. 49 Physical properties in terms of tensile strength (top) and 50% modulus (bottom) for CR-XNBR blends obtained from self-crosslinking and sulfur-crosslinking processes...

Fig. 50 WAXD patterns of CR and XNBR and their blends obtained from self-crosslinking top) and sulfur crosslinking bottom) processes...

Table II Glass transition temperature of self-crosslinked CR/XNBR rubber blends...

Fig. 52 Tan <5 versus temperature plots of CR-XNBR blends vulcanized by sulfur (top). Storage modulus versus temperature plots of self-crosslinked CR-XNBR blends (bottom)...

The micrographs obtained from scanning electron microscopy are shown in Fig. 54 for the tensile fractured surface of 50 CR/50 XNBR self-crosslinked blend filled with 10 phr layered silicate (Fig. 54a) and for the same blend without any... 

Polymeric binders based upon a vinyl acetate and ethylene backbone incorporating a self crosslinking monomer have been widely used in the nonwoven industry (3). 

Ethylene in the polymer provides softness to the product and is low cost. However, the softness in the product often comes at the expense of its wet tensile strength. Increasing the level of self crosslinkable monomer in the polymer often is not a viable option to increase the wet tensile strength. 

J.J. Rabasco, J.R. Boylan, D. Sagl, and R.B. Jones, Self-crosslinking vinyl acetate-ethylene polymeric binders for nonwoven webs, US Patent 7 485 590, assigned to Wacker Chemical Corporation, February 3,2009. 

Marschiiz, M.K. and Bernkop-Schnirch, A., Thiolated polymers self-crosslinking properties of thi-olated 450 kDa poly(acrylic acid) and their in uence on mucoadhdsim l. Pharm. Sci., 15, 387,... 

The IR spectra of a self-crosslinked blend of CSM/XNBR [125] following the reaction scheme (Scheme 3.3b) are presented in Figure 3.6. 

Figure 3.6 FTIR-ATR spectra of (a) uncrosslinked 50/50 (w/w) CSM/XNBR blend, (b) self-crosslinked 50/50 (w/w) CSM/XNBR blend, (c) (b-a) difference spectrum...

It is concluded that IR spectroscopy provides information on qualitative as well quantitative analyses of rubbery materials, apart from their microstructures (that is, whether cis or trans, syndiotactic, atactic or isotactic). Different types of rubber blends (compatibilised or self-crosslinked) can be identified by the infrared spectroscopy. Synthesis, and degradation of polymers can also be followed by IR spectra. Mechanism of interaction between rubbers and fillers, can also be studied by IR-spectra. Different types of chemical reactions like the milling behaviour of rubbers, mechanism of adhesion and degradation can also be studied with the help of IR spectroscopy. The technique plays a great role in the product analysis under reverse engineering. 

Raman and IR spectroscopic studies dealing with the qualitative and/or quantitative determination of rubber compounding ingredients, i.e., the elastomer itself [22, 26-31], fillers [32, 33], vulcanisation chemicals and other additives [34-37], are not included here. The same applies to studies dealing with the crosslinking of elastomers by means of chemicals other than sulfur or peroxide [38-41], self-crosslinking of elastomers blends [42-44], crystallisation (strain-induced) [45-48] and oxidation/ageing [49-53]. 

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