Polyamide heat deflection temperature

An all aromatic polyetherimide is made by Du Pont from reaction of pyromelUtic dianhydride and 4,4 -oxydianiline and is sold as Kapton. It possesses excellent thermal stabiUty, mechanical characteristics, and electrical properties, as indicated in Table 3. The high heat-deflection temperature of the resin limits its processibiUty. Kapton is available as general-purpose film and used in appHcations such as washers and gaskets. Often the resin is not used directly rather, the more tractable polyamide acid intermediate is appHed in solution to a surface and then is thermally imidi2ed as the solvent evaporates. 

As with the aliphatic polyamides, the heat deflection temperature (under 1.82 MPa load) of about 96°C is similar to the figure for the Tg. As a result there is little demand for unfilled polymer, and commercial polymers are normally filled. The inclusion of 30-50% glass fibre brings the heat deflection temperature under load into the range 217-231°C, which is very close to the crystalline melting point. This is in accord with the common observation that with many crystalline polymers the deflection temperature (1.82 MPa load) of unfilled material is close to the Tg and that of glass-filled material is close to the T. ... 

TDI isomers, 210 Tear strength tests, 242-243 TEDA. See Triethylene diamine (TEDA) Telechelic oligomers, 456, 457 copolymerization of, 453-454 Telechelics, from polybutadiene, 456-459 TEM technique, 163-164 Temperature, polyamide shear modulus and, 138. See also /3-transition temperature (7)>) Brill temperature Deblocking temperatures //-transition temperature (Ty) Glass transition temperature (7) ) Heat deflection temperature (HDT) Heat distortion temperature (HDT) High-temperature entries Low-temperature entries Melting temperature (Fm) Modulu s - temperature relationship Thermal entries Tensile strength, 3, 242 TEOS. See Tetraethoxysilane (TEOS)... 

For polyamine-cured resin, recycle of presoaked epoxy also increased both impact strength and heat deflection temperature. For polyamide-cured resin, recycle also increased volume resistivity. Pre-soaked recycle dramatically increased adhesion to aluminum, especially in the anhydride system. 

The aromatic polyamides (aramids) have been produced by the interfacial condensation of aromatic diamines, such as 1, 3-phen-ylenediamine and isophthaloyl chloride in chloroform. Amorphous transparent aramids with heat deflection temperatures of 160 C... 

The polyamide-imide (Torlon, PA-1) has a heat deflection temperature of 285°C. A Ford automobile prototype engine has been built from PA-1.( >... 

Polyamide polymers use glass fiber to control brittleness. Tensile strengths are increased by a factor of 3 and heat deflection temperature increases from 150 to 500°F (66 to 260°C). 

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. 

The best-known are General Electric Ultem poly (ether imides) these offer heat deflection temperatures of 207 to 221°C and continuous service temperatures of 170 to 180°C. Also popular are Amoco Torlon polyamide-imides, with heat deflection temperatures of 278 to 282°C. More specialized are Ciba-Geigy trimethyl phenyl indane polyimides, with heat deflection temperatures of 232 to 257°C, embrittlement times of >2000 hr at 200°C... 

The heat deflection temperature (or heat distortion temperature) is an important material property mostly used to determine a material s useful temperature operating range. It refers to the temperature below which a moulded object can hold its own shape. It can be determined using a dynamic mechanical analyser set to apply a constant force. The HDT was determined for blends of plasticized soy flour (52% protein) and polyamide (nylon) as 45 °C when plasticized with 20 wt% sorbital, 35 °C when plasticized with 20 wt% glycerol, and 39 °C when plasticized with 10 wt% of each." When such a blend is used to make composites with natural flbres, increasing content of natural fibres also increased the HDT. 

Mica provides similar benefits in a wide range of thermoplastic and thermoset composites including polyolefins, polyamides and styrenics. It is also reported that surface coated mica further increases tensile strength, flexural strength and modulus, and heat deflection temperature. The automobile industry is the main user of mica-filled composites, either with polypropylene or nylon as polymer matrix. Up to 40% mica loadings are used, sometimes in association with calcium carbonate, to produce various injection... 

Polyamide-imides (PAIs) are thermoplastic amorphous polymers prepared by the condensation of an aromatic diamine, such as methylene diamine, and an anhydride, such as trimellitic add chloride. PAIs have good mechanical, thermal, chemical resistance, high strength, melt processability, and high heat capacity. They can be processed into a variety of forms, such as injection or compression molded articles, coatings, films, fiber, and adhesives. The typical heat deflection temperature for neat molded PAI is 278°C,but reinforcements are often used to improve mechanical properties. PAIs are generally soluble in strong aprotic solvents such as NMP and DMAc, and thus misdble blends with PBI are feasible. 

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