Reversible crosslinking

Physical mixtures consist of reversibly crosslinked and uncrosslinked hydrocolloid compositions and hydrocolloids. These show improved dispersion properties [1708]. 

K. Szablikowski, W. Lange, R. Kiesewetter, and E. Reinhardt. Easily dispersible blends of reversibly crosslinked and uncrosslinked hydrocolloids, with aldehydes as crosslinker (Abmischungen von mit Alde-hyden Reversibel Vemetzten Hydrokolloidmischungen und Unvemet-zten Hydrokolloiden mit Verbesserter Dispergierbarkeit). Patent EP 686666, 1995. 

Xiang, C.C. et al. (2004) Using DSP, a reversible crosslinker, to fix tissue sections for immunostaining, microdissection and expression profiling. Nucleic Acids Res. 32, el 85. 

Experiments supporting the actual participation of amine acid salts In the crossUnklng of cyclic hemlamidals were described In the companion paper (1). Amine add salt catalysts are milder than mineral adds, causing less degradation of the substrate the resulting secondary amine appears to be a less reversible crosslink than the ether formed with mineral adds and amine crosslink centers have the potential to Involve up to three functional monomer units 1n the crosslink, leading to a tighter network (Scheme 2). 

Russo, E., Giancotti, V., Cosini, S., and Crane-Robinson, C. 1981. Identification of a heterologous histone complex using reversible crosslinking. Int. J. Biol. Macromol. 3 367-369. 

Fig. 5.6. Two-dimensional gel electrophoresis of reversibly crosslinked human erythrocyte membranes. Ghosts were crosslinked with methyl 3-(4-azidophenyldithio)propionimidate and electrophoresed on a 0.5% agarose-1.75% polyacrylamide tube gel. The gel was treated with P-mercaptoethanol (10 mM), and electrophoresed in the second dimension on a 4 to 12 % gradient polyacrylamide slab gel. Some of the crosslinked components (mostly oligomers of spectrin) were incompletely cleaved. (Ji et al., 1980).

Thixotropic agent Undergo reversible crosslinking reactions via hydrogen bridge bonds, forming a gel structure Added as the last ingredient in the formulation. Mainly used for water-based acrylics... 

Similarly, Figure 1.20 shows a typical monomer combination leading to branched and ultimately crosslinked polymers, which are thermally reversible all the way to the initial monomer mixture [37]. Finally, Figure 1.21 shows the reversible crosslinking of a linear furan copolymer by an oligomeric bismale-imide [41]. 

Milner PA, Gogel G, Barber J. Investigation of the spatial relationships between Photosystem 2 polypeptides by reversible crosslinking and diagonal electrophoresis. Photosynth Res 1987 13 185-198. 

Add 120 pL of elution buffer to the supernatant in the new tube. Reverse crosslinks at 65°C overnight in water bath. 

To recycle rubber more effectively, one could look for new ways to reverse crosslinking and vulcanization. 

Rubbery behavior—large, reversible extensibility—implies an absence of crystallinity, and this is usually the case for undeformed elastomers. However, small extents of crystallization may be present at ambient temperature in some elastomers, including EPDM with high ethylene content, epichlorohydrin rubber, and polypropylene oxide. The crystallites in these materials can act as reinforcing agents. Many thermoplastic elastomers have crystalline domains that function as reversible crosslinks (Rzymski and Radusch, 2005 Bhowmick and Stephens, 2001). 

PA-MI/PA-F cross-linked polymers showed thermally reversible crosslinking behavior via DA and retro-DA reactions. Cross-linked PA-MI/PA-F films exhibited enhanced toughness and mechanical properties over PA-MI and PA-F precursors. Moreover, PA-MI/PA-F films also showed excellent thermal self-repairing behavior. 

Park, H., Kang, S. W., Kim, B. S., Mooney, D. J. Lee, K. Y. (2009a) Shear-reversibly crosslinked alginate hydrogels for tissue engineering. Macromol Biosci, 9, 895-901. 

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