Modification of Nylon 6 by phenol-containing polymers

Abstract

A crystalline polymer, Nylon 6, was selectively blended with various amorphous polymers containing phenolic moieties. It was found that moisture absorption by the amide group in Nylon 6 could effectively be reduced by blending with p-Cl-novolac at ratios as low as 2 phr (part per hundred resin). Blends of Nylon 6 with vinylphenol homopolymer and its copolymer with styrene also showed reduced moisture uptakes, but the effect was less dramatic than that of the p-Cl-novolac blend at all blend ratios. Novolac content in excess of 5 phr shows little additional advantage in moisture reduction. Thermal transitions of blends of Nylon 6 with poly(vinyl phenol), its copolymer, and p-Cl-novolac were also investigated. At a blend ratio of 5 phr, p-Cl-novolac caused a larger increase in glass transition temperature than the other two blends. The melting temperatures of the blends were little influenced by low levels of the amorphous polymer incorporation, but broader melting endotherms in the differential scanning calorimetry scans were observed.

Moisture Absorption Behavior of Carbon Fiber-Reinforced Monomer Casting Nylon Composites

“…One effective way to decrease the moisture content of nylon materials is to reduce their amide groups. For example, Huang et al successfully limited the moisture absorption of nylon-6 by blending it with vinyl phenol that was categorized as hydrogen bond donors [10]. On the other hand, the high moisture contents of the MC nylon composites are due partly to the low degree of crystallinity (lower than 40%).…”

Multifaceted property tailoring of polyamide 6 by blending miscible and immiscible components: ternary blends of polyamide 6/polyethylene terephthalate/phenol novolac

“…Various polymer blends have been proposed to improve the mechanical properties of PA6 under humid and high-temperature conditions. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Owing to the small mixing enthalpy of macromolecules, almost all polymer combinations are immiscible 5 and thus, previous studies have mainly conducted PA6 polymer blending with immiscible components. [7][8][9][10][11][12][13][14] Blending high-T g polymers, such as poly(phenylene sulde), 7,8 poly(phenylene oxide), [9][10][11] and polycarbonate (PC) [12][13][14] with PA6 are representative approaches to increase the PA6 stiffness at high temperatures.…”

“…On the other hand, phenol-containing polymers, such as phenol novolac (PN) and PA6 blends, have been reported as miscible systems. [15][16][17][18][19][20][21] PN forms strong hydrogen bonds with PA6, which contribute to the miscibility of such blends. 16,18 Miscible components can increase the T g of PA6, and we previously reported that high-molecular-weight PN efficiently increases the T g of PA6.…”

“…20 Furthermore, it has been reported that PN prevents water absorption of PA6 by the contribution of strong hydrogen bonding. 15,[18][19][20] Although miscible and immiscible components are known to enhance different PA6 properties, to the best of our knowledge, no studies on PA6 ternary blends comprising both immiscible and miscible components have been conducted to date.…”

Polyamide 6 and high molecular weight phenol novolac blend having excellent mechanical properties in humid conditions

“…On the other hand, there have been some more fundamental attempts, which are preventing water absorption and increasing the T g of PA6 by blending it with phenol-containing polymers such as phenol novolac (PN), 5 –7 polyvinylphenol, 8 and their derivatives. 9 These polymers can form strong hydrogen bonds between the carbonyl groups of PA6 and the hydroxyl groups of phenol-containing polymers. Quantum mechanical calculations have shown that the hydrogen bonds between PA6 and phenol-containing polymers are stronger than the hydrogen bond between PA6 and water molecules.…”