Silicone latex IPNs

A few papers dealing with silicone latex IPNs have appeared. Frisch et al. [ 111 ] patented a process whereby two emulsions were prepared the first contained a hydroxyl-terminated PDMS and stannous octoate, the second a crosslinked polyurethane, poly(urethaneurea) or polyacrylate latex. The two lattices were blended and a film was cast and cured at 120 °C. The mechanical properties were found to be enhanced, especially in the case of the polyacrylate/PDMS IPN. Noteworthy is the fact that semi-IPNs such as the thermally stable... 

Silicone co-polymer networks and IPNs have recently been reviewed.321 The development of IPNs is briefly described, and the definitions of the main (non-exclusive) classes of the IPNs are cited. Examples of latex IPNs, simultaneous and sequential IPNs, semi-IPNs, and thermoplastic IPNs are provided. The use of silicone-silicone IPNs in studies of model silicone networks is also illustrated. Networks in which siloxane and non-siloxane components are connected via chemical bonds are considered co-polymer networks, although some other names have been applied to such networks. Today, some of the examples in this category should, perhaps, be discussed as organic-inorganic hybrids, or nanocomposites. Silicone IPNs are discussed in almost all of the major references dealing with IPNs.322-324 Silicone IPNs are also briefly discussed in some other, previously cited, reviews.291,306... 

PTFE/PDMS can be obtained via a similar process [112]. PTFE chains are trapped in the PDMS network during casting. Jones et al. [113] also patented a process where adipic acid and hexane diamine (or f -caprolactam [114]) were added to a silicone latex leading to the formation of a polyamide/PDMS semi-IPN. 

SiUcone-modified styrene-butyl acrylate copolymer latex was synthesised by emulsion copolymerisation using octamethylcyclotetrasiloxane(D4), styrene and butyl acrylate as raw materials, potassium persulphate as initiator and propylmethacrylate triethoxysilane as crosslinking agent. The IR spectroscopic studies showed that the vinyl monomers were completely copolymerised with D4. The prepared silicone-modified copolymer latex with the IPNs tended to have higher stability and better toluene and water resistance than styrene-butyl acrylate copolymer latex. The glossiness of coated paper was improved with silicone-modified copolymer latex and it was at a maximum when D4 was about 3% of total monomers. 16 refs. 

A curable epoxy resin containing a crosslinked elastomeric latex " yields a special type of sequential IPN. The elastomers mentioned include SBR, EPR, NBR, silicone rubber, and PEA. Hawkins " described an epoxy/polyurethane semi-SIN, and Mendoyanis " revealed an epoxy/liquid rubber SIN. The liquid rubbers were based on polysulfide rubber or polyethylene. The final products could be extended to 400% at... 

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