THERMALLY CONDUCTIVE POLYMER COMPOSITIONS
A thermally conductive polymer composition, comprising a polymer, conductive charges in an amount of about 35% by weight or less, and a compatibilizer, the composition having a transverse thermal conductivity of about 0.5 W/m/K or more and a deformation at break of about 850% or less The composition is fabricated by i) feeding a polymer and a compatibilizer in a feed zone of an extruder to obtain a melted resin; ii) introducing directly into the extruder downstream of the feed zone, conductive charges in an amount of about 35% by weight or less into the melted resin; and iii) providing a degassing zone before the output of the thermally conductive polymer composition produced.
1 . A thermally conductive polymer composition, comprising a polymer, conductive charges in an amount of about 35% by weight or less, and a compatibilizer, said composition having a transverse thermal conductivity of about 0.5 W/m/K or more and a deformation at break of about 850% or less.
2 . The composition according to claim 1 , wherein said polymer is polyethylene, polypropylene, poly(methyl methacrylate), polystyrene, polyamide, poly(butylene terephthalate), polycarbonate or acrylonitrile-butadiene-styrene copolymer, said conductive charges are metals, metal oxides, ceramics, minerals, carbon materials, aluminum, copper, aluminum oxide, magnesium oxide, boron nitride, graphite, carbon black or combinations thereof, said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate, impact modifiers or combinations thereof.
3 . The composition according to claim 1 , wherein said polymer is a polyolefin.
4 . The composition according to claim 1 , wherein said polymer comprises polyethylene, said conductive charges comprise exfoliated graphite in an amount of about 30% by weight or less, and said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate or combinations thereof.
5 . The composition according to claim 1 , wherein said polymer comprises polyethylene, said conductive charges comprise exfoliated graphite in an amount of about 12% by weight or less, and said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate or combinations thereof.
6 . The composition according to claim 1 , wherein said polymer comprises polyethylene, said conductive charges comprise exfoliated graphite in an amount of about 5% by weight or less, and said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate or combinations thereof.
7 . The composition according to claim 1 , wherein said polymer comprises polyethylene, said conductive charges comprise nanoparticles consisting of stacks of graphene that are about 1 to about 15 nanometers thick, with diameters ranging from sub-micrometer to about 100 micrometers.
8 . A method for making a thermally conductive polymer composition having a transverse thermal conductivity of about 0.5 W/m/K or more and a deformation at break of about 850% or less, comprising the steps of:
i) feeding a polymer and a compatibilizer in a feed zone of an extruder to obtain a melted resin;
ii) introducing directly into the extruder, downstream of said feed zone, conductive charges in an amount of about 35% by weight or less into the melted resin; and
iii) providing a degassing zone before the output of the thermally conductive polymer composition produced.
9 . The method of claim 8 , wherein said step ii) comprises introducing about 30% by weight or less of said conductive charges into the melted resin.
10 . The method of claim 8 , wherein said step ii) comprises introducing about 12% by weight or less of said conductive charges into the melted resin.
11 . The method of claim 8 , wherein said step ii) comprises introducing about 5% by weight or less of said conductive charges into the melted resin.
12 . The method of claim 8 , wherein said step i) comprises feeding said polymer with maleic anhydride, calcium stearate, pentaerythritol stearate or combinations thereof.
13 . The method of claim 8 , wherein said step i) comprises feeding impact modifiers together with said polymer.
14 . The method of claim 8 , wherein said polymer is polyethylene, polypropylene, poly(methyl methacrylate), polystyrene, polyamide, poly(butylene terephthalate), polycarbonate or acrylonitrile-butadiene-styrene copolymer, said conductive charges are metals, metal oxides, ceramics, minerals, carbon materials, aluminum, copper, aluminum oxide, magnesium oxide, boron nitride, graphite, carbon black or combinations thereof, said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate, impact modifiers or combinations thereof.
15 . The method of claim 8 , wherein said polymer is HDPE, said conductive charges are exfoliated graphite, and said compatibilizer is maleic anhydride, calcium stearate, pentaerythritol stearate or a combination thereof.
16 . A heat exchanger, made in a polymer composition comprising a polymer, conductive charges in an amount of about 35% by weight or less, and a compatibilizer, said heat exchanger having a transverse thermal conductivity of about 0.5 W/m/K or more and a deformation at break of about 850% or less.
17 . The heat exchanger of claim 16 , wherein said polymer is polyethylene, polypropylene, poly(methyl methacrylate), polystyrene, polyamide, poly(butylene terephthalate), polycarbonate or acrylonitrile-butadiene-styrene copolymer, said conductive charges are metals, metal oxides, ceramics, minerals, carbon materials, aluminum, copper, aluminum oxide, magnesium oxide, boron nitride, graphite, carbon black or combinations thereof, said compatibilizer comprises maleic anhydride, calcium stearate, pentaerythritol stearate, impact modifiers or combinations thereof.
18 . The heat exchanger of claim 16 , wherein said polymer is HDPE, said conductive charges are exfoliated graphite, and said compatibilizer is maleic anhydride, calcium stearate, pentaerythritol stearate or a combination thereof.