Poly-m-xylylene

A rare example of a crystallisable aromatic polyamide used as a plastics material is poly-m-xylylene adipamide. 

Typical values of rate coefficients reported [92] for polyamidation in m-cresol include 7.7 x 10 g mmole" sec" for the preparation of poly-(m-xylylene adipamide) and 4.2 (p-xylylene sebacamide) (Table 6). 

Poly(a,a,a, a -tetrafluoro-p-xylylene) Poly(m-xylylene adipamide)... 

Poly(m-phenylene isophthalamide) 660 to 700 Poly(m-xylylene adipamide) 518... 

B. De Roover, Etude des Melauges Constiues de Poly(m-xylylene Adipamide) et de Polypropylene Eonctionnalise Parlankydride maleique, PhD Thesis, Universite Catholique de Louvain, 1994. 

A crystalline, partially aromatic polyamide, poly-m-xylylene-adipamide, (also known as MXD-6) with repeat units of... 

Silarylene Polymers Containing m-Xvlvlene Units. A majority of the silarylene type siloxane polymers which have been worked on to date contain silicon-phenyl bonds. After an extensive literature search, only one type of polymer was found which contained an arylene group that does not have silphenylene bonds in the polymer backbone. The work, done mainly by Rosenberg and Choe 15-17 of the Air Force Materials Laboratory, is based on polymers which have a general structure as shown below, referred to as poly(m-xylylene-siloxanylenes), (9). 

A modified melt blending method has been developed for preparing exfoliated nanocomposites of poly(m-xylylene adipamide) with sodium montmoril-lonite [100]. There, an aqueous solution of sodium montmorillonite was blended with the polymer in a twin-screw extruder. This kind of mixing ensures that the silica nanoparticles are exfoliated in the polymer matrix through fixing the nanoparticles within the polymer matrix just as they are in water. Oxygen permeation data show enhanced the barrier properties of the nanocomposites. 

Wang Y, Jabarin SA. Novel preparation method for enhancing nanoparticle dispersion and barrier properties of poly(ethylene terephthalate) and poly (m-xylylene adipamide). J Appl Polym Sci2013 129(3) 1455-65. 

Two classes of FASIL elastomers have been chosen for preliminary evaluation the methyl- and 3,3,3-trifluoro-propyl-substituted poly (m-xylylene siloxanylenes) (129) and the corresponding poly(m-phenylene siloxanes) (124). 

An example of a crystallizable aromatic polyamide is poly-m-xylylene adipamide. It has a Tg near 85 to 100°C and a of 235 to 240°C. To obtain high heat deflection temperature, the filled grades are normally sold. Applications include gears, electrical plugs, and mowing machine components. 

It may be noted that poly-p-xylylene is considerably less stable than poly-p-phenylene (Section 19.5) owing to the presence of the relatively weak dibenzyl linkages. It may also be noted that the isomeric polyxylylenes have been prepared but poly-o-xylylene has a polymer melt temperature of 110°C whilst poly-m-xylylene has a softening temperature of only 60°C these polymers are therefore of no immediate interest. 

Poly(m-xylylene sebacamide) Poly(p-xylylene sebacamide) 302.42 193 402 t... 

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