Effect of nanoparticle and glass fiber on the hydrothermal aging of polyamide 6

Abstract

Hydrothermal aging behavior of polyamide 6 (PA6) and its composites (PA6/calcium carbonate [CaCO3] and PA6/short glass fiber [SGF]) was systematically investigated using infrared spectroscopy, dynamic mechanical analysis, differential scanning calorimetry, and wide‐angle X‐ray diffraction as well as mechanical measurements. It was found that the water absorption mechanism is strongly affected by the presence of fillers. SGF‐reinforced PA6 composites absorb less water than PA6 and PA6/CaCO3 composites under the same hydrothermal condition. PA6 with 10 wt% SGF exhibits great resistance to hydrothermal aging, which is attributed to the higher crystallinity and larger α‐form fraction.

Borane catalysis for epoxide (co)polymerization

“…Thus, both activity and selectivity are lower for the more Lewis acidic Ph 3 B compared to Et 3 B. Similar was reported by Li, 117 Wang, Li and co-workers 115 as well as Zhang. 114 In sharp contrast, the aforementioned copolymerization of the electron-poor isocyanate TSI and PO to yield polyurethanes was rapid and strongly exothermic in the presence of Ph 3 B.…”

“…relative to a phosphazene base) are sufficient for the copolymerization of PA with different epoxides. 117 Wang, Li and co-workers described the highly regioselective and stereoregular copolmyerization of various epoxides with tricyclic anhydrides such as cis-5-norbornene-exo-2,3-dicarboxylic anhydride (exo-CPMA), which is the Diels-Alder product of cyclopentadiene and MA. 115 Such copolymers can display a high T g , but to achieve this feature, epimerization has to be suppressed and both the relative stereochemistry as well as the regioselectivity must be controlled.…”

Organo-catalyzed/initiated ring opening co-polymerization of cyclic anhydrides and epoxides: an emerging story

“…It was partially neutralized working with an excess of acid (CTPB/PhCO 2 H = 0.5:1) and led to the production of a welldefined polyester material exhibiting a monomodal GPC trace. In 2020, 57 the same authors performed a similar study but using a Lewis acid such as BEt 3 as co-catalyst in the presence/absence of BnOH as an initiator (Scheme 17) for the co-polymerization of phthalic anhydride 1a with epoxides 2d,e,l CTPB alone led to no polymerization while in the presence of BnOH, under similar conditions, 56 to 99% conversion of anhydride was observed (60-100°C, 10-48 h).…”

New insight into the thermal‐oxidative stability of polyamide 6: A comparison investigation on the effect of hindered amine and CuI/KI

“…The melting temperature of α‐form in PA6 is about 10°C higher than γ‐form, [ 27 ] so the melting multiple peaks are caused by the melting of γ‐form ( T m1 ), α‐form ( T m2 ) and recrystallization ( T m3 ) during heating. [ 28 ]…”