Variable‐temperature FTIR studies on thermal stability of hydrogen bonding in nylon 6/mesoporous silica nanocomposite

Li, Lanjie; Yang, Guisheng

doi:10.1002/pi.2559

Cited by 31 publications

(19 citation statements)

References 32 publications

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“…As shown in Figure 5a and Table 1, the bands at 1633 and 1654 cm −1 are attributed to the ordered hydrogen-bonded CO in pure PA6 crystalline phase and the disordered hydrogen-bonded CO in PA6 amorphous domains, respectively. [25,26] The band at 1680 cm −1 at 83 °C (Figure 5b) is assigned to "free" CO in the homo-mixed domains. [25] According to the studies of Saiani et al [6] and Yu and Jo, [27] the incorporation of soft segments can enhance the purity and crystal perfectness of PA6 backbones, so we may assign the band at 1608 cm −1 to the ordered hydrogen-bonded CO in phase-separated mesophase.…”

Section: Phase Evolution Of Tpae-50 During Heating From 30 To 220 °Cmentioning

confidence: 99%

Phase Evolution of Polyamide 6 (PA6)‐Based Thermoplastic Elastomers during Heating and Cooling Investigated by Moving‐Window 2D Correlation Infrared Spectroscopy

Yuan

Wang

et al. 2020

Macro Materials & Eng

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To illustrate the complex phase evolution of polyamide 6 (PA6)‐based thermoplastic elastomer (TPAE‐50) with a three‐phase system (a pure PA6 crystalline phase, a phase‐separated mesophase, and a mixed phase) during cooling and heating, the in situ IR spectroscopy combined with moving‐window 2D correlation analysis is employed. The mixing of PA6 amorphous domains with soft domains and the melting of imperfect PA6 crystalline domains of TPAE‐50 occur from 60 °C with the increasing temperature. Brill transition happens to the elastomer during heating and cooling at 140–160 and 170–135 °C, respectively. Microphase separation of TPAE‐50 during cooling is formed and can be composed of three processes: the first process (200–180 °C) is motivated by the crystallization of the elastomer; the second process (170–140 °C) results from the transition of homo‐mixed domains in the mixed phase to PA6 amorphous and soft domains; the third process (125–60 °C) leads to the formation of imperfect PA6 crystalline domains in phase‐separated mesophase.

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Section: Phase Evolution Of Tpae-50 During Heating From 30 To 220 °Cmentioning

confidence: 99%

Phase Evolution of Polyamide 6 (PA6)‐Based Thermoplastic Elastomers during Heating and Cooling Investigated by Moving‐Window 2D Correlation Infrared Spectroscopy

Yuan

Wang

et al. 2020

Macro Materials & Eng

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“…Outdoor exposure tests of the injection-molding standard specimen of PA6 were performed at six national standard natural exposure stations (Qionghai, Guangzhou, Qingdao, Lhasa, Hailaer, and Ruoqiang) from September 2011 to September 2014 and lasted for 3 years. Specimens were collected after different time intervals (1,3,6,12,18,24,30, and 36 months); they were clamped at both ends by aluminum plates, put on racks in a horizon position, and tilted at 458 facing south for exposure.…”

Section: Weathering Experimentsmentioning

confidence: 99%

“…Polyamide 6 (PA6), as one of the most common engineering plastics, has a wide range of applications in industry because of its excellent mechanical properties, oil resistance, and abrasive resistance. 1,2 Usually, the carbon-hydrogen bond on the methylene group adjacent to nitrogen is considered to be the weakest bond, and the most complicated oxidation reaction proceeds on this carbon with exposure to heat, oxygen, light, and water during long-term service. An obvious deterioration of the chemical structures and physical performances can occur and can, consequently, lead to the failure of polyamide material and limit its use.…”

Section: Introductionmentioning

confidence: 99%

Outdoor weathering behavior of polyamide 6 under various climates in China

Shi

Gao

Tao

et al. 2016

J of Applied Polymer Sci

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The outdoor natural weathering of polyamide 6 (PA6) was performed at six national standard natural exposure stations (at Qionghai, Guangzhou, Qingdao, Lhasa, Hailaer, and Ruoqiang), which represented the six typical climates over China. The outdoor aging behavior was studied. We found that under high temperature and humidity in the areas of Guangzhou, Qionghai, and Qingdao, the concentration of the end carboxyl group of PA6 increased significantly and the molecular weight decreased because of serious hydrolytic degradation. This resulted in a deterioration of the mechanical properties, high yellowing degree, and serious damage of the sample surface. While in the areas of Lhasa and Ruoqiang, with the relatively low temperature, humidity, and oxygen content in the atmosphere, the aging degree and corrosion index were low, and this resulted in the slow change of performances. Humidity, temperature, and rainfall may be the main environmental factors affecting the degradation of PA6. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44231.

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“…Some researchers have extensively explored the crystalline phase transitions during the process of heating or cooling [9][10][11]. The triclinic α-crystal structure of PA 66 may convert into the pseudo γ-hexagonal-crystal structure in the course of heating, in a process named the Brill transition [12][13][14]; the corresponding transition temperature is named the Brill transition temperature, or simply T B [15][16][17][18][19]. Generally speaking, the T B will be changed with the grain sizes and state, and sometimes even exceeds the melting point (T m ) [20,21].…”

Section: Introductionmentioning

confidence: 99%

The Thermal Behavior of γ-PA1010: Evolution of Structure and Morphology in the Simultaneous Thermal Stretched Films

Zhang

Líu

et al. 2020

Materials

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In this work, polyamide 1010 (PA1010) films were prepared by melt-quenching. A wide-angle X-ray diffractometer (WAXD) with a thermal stretching stage was used to investigate the structure transformation, crystallinity and degree of orientation in the course of simultaneous thermally stretched PA1010. The crystallinity increased along with the increase of draw ratio and then decreased as the draw ratio was over 2.00 times-which the maximum value reached when the draw ratio was about 2.00 times. The degree of orientation of γ-PA1010 was much greater at higher temperature than room temperature (RT); the difference gradually became weaker with the increase of draw ratio. There was a linear relationship between the draw ratios and tensile force at higher temperatures, and the tensile force increased with the increase of draw ratios. The tensile force may induce crystallization and promote orientation in the course of simultaneous thermally stretched PA1010. These phenomena are beneficial to understand the structure-processing-performance relationship and provide some theoretical basis for the processing and production.

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Variable‐temperature FTIR studies on thermal stability of hydrogen bonding in nylon 6/mesoporous silica nanocomposite

Cited by 31 publications

References 32 publications

Phase Evolution of Polyamide 6 (PA6)‐Based Thermoplastic Elastomers during Heating and Cooling Investigated by Moving‐Window 2D Correlation Infrared Spectroscopy

Phase Evolution of Polyamide 6 (PA6)‐Based Thermoplastic Elastomers during Heating and Cooling Investigated by Moving‐Window 2D Correlation Infrared Spectroscopy

Outdoor weathering behavior of polyamide 6 under various climates in China

The Thermal Behavior of γ-PA1010: Evolution of Structure and Morphology in the Simultaneous Thermal Stretched Films

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