Miscibility in binary blends of aromatic and alicyclic polyamides

Abstract

Miscibility was studied for four polyamide blends of 6I/6T [copolymer consisting of 1,6-hexamethylene diamine and isophthalic acid (6I) (70 wt %) and terephthalic acid (6T) (30 wt %)] with MXD6 (polyamide of m-xylenediamine and adipic acid), BAC6 (polyamide of 1,3-bis(aminomethyl)cyclohexane and adipic acid), TR55 (copolymer consisting of nylon 11 (30 wt %), and polyamide of bis(3-methyl, 4-aminocyclohexyl)methane (30 wt %) and isophthalic acid (70 wt %), and CX7323 (polyamide of bis(4-aminocyclohexyl)methane and dodecanedicarboxylic acid), using differential scanning calorimetry, X-ray diffraction method, and electronmicroscopic observation. In quenched MXD6/(6I/ 6T) and BAC6/(6I/6T) blends, MXD6 and BAC6 components were miscible to 6I/6T, but TR55 and CX7323 components were completely phase-separated from 6I/6T. Interestingly on electronmicroscopic observations, TR55 and CX7323 components were seen as droplets in 6I/6T medium when the content is low, but when 50 wt %, a layered structure was constructed with 6I/6T, reminiscent of morphological structure in block copolymer.

Polyamides – Still Strong After Seventy Years

“…The DuPont company at one time advertised [52] [54] have prepared and studied polymers of this diamine with a series of straight-chain diacids. Endo et al [55] report, for the polyamide of 1,3-BAC and adipic acid, T g of 107 8C and T m of 227 8C. Cyclohexanebis(methylamine), both the 1,3 and 1,4 isomer, is commonly referred to as CBMA.…”

Synthesis, characterization and thermal decomposition of poly(decamethylene 2,6-naphthalamide)

“…Aromatic polyamides and semiaromatic polyamides have been widely used in many industrial and commercial applications, especially in surface-mount technology (SMT) and automobile industries, by virtue of their excellent characteristics such as good thermal stability, chemical resistance, low creep and high modulus [1][2][3]. The commonly mentioned aromatic and semiaromatic polyamides can not be processed by melting method due to their high melting temperature and relatively lower decomposition temperatures [4][5][6].…”

Synthesis and thermal decomposition of poly(dodecamethylene terephthalamide)

“…1,2 The commonly mentioned aromatic and semiaromatic polyamides cannot be processed by melting method, because their decomposition temperatures are usually lower than melting temperatures, 3,4 such as PA6T. To improve their processing performance, several approaches have been made through synthetic modification by incorporation of flexible linkages, 5 bulky pendant groups, 6 and noncoplanar biphenylene moieties 7 into molecular chains of semiaromatic polyamides.…”