Direct investigations of deformation and yield induced structure transitions in polyamide 6 below glass transition temperature with WAXS and SAXS

Guo, Huilong; Wang, Jiayi; Zhou, Chengbo; Zhang, Wenyang; Wang, Zixuan; Xu, Bin; Li, Jingqing; Shang, Yingrui; Christiansen, Jesper de Claville; Yu, Donghong; Wu, Zhonghua; Jiang, Shichun

doi:10.1016/j.polymer.2015.06.013

Cited by 23 publications

(27 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the α‐phase, the chains are fully extended, whereas in the γ‐phase the methylene next to the amide groups adopts a skew conformation. As the calculating result in our previous research, the initial alpha and gamma phase contents of the same PA samples are about 17% and 9%, respectively. In Fig.…”

Section: Resultsmentioning

confidence: 99%

“…a and b, the diffractions of α (200), α (002/202), and γ (200) both decrease and merge together along with the strain increases. The phenomenon that these diffractions along vertical direction decrease with the increasing strain is quite different with the situation at 30 °C . In the case of 30 °C, the diffractions of α (200), α (002/202), and γ (200) along vertical direction are enhanced gradually until sample fracture, for the continuous orientation induced by tensile force.…”

Section: Resultsmentioning

confidence: 99%

“…The d ac obtained from SAXS patterns at 60 and 90 °C show similar changes, which are both different from that at 30 °C. Besides the slow decreasing of d acv due to compression induced by tensile deformation, the two d ach both show increase‐ plateau ‐decrease feature, unlike the situation that with increase‐ plateau ‐increase feature at 30 °C . The increase‐ plateau‐ increase feature indicates that the lamellae are separated within a relatively simple and efficient progress.…”

Section: Resultsmentioning

confidence: 99%

“…The scattering intensity changes caused by varying sample thickness were corrected by measuring the ionization chambers and corresponding data correction. Besides the experimental temperature adopted, the sample preparation and the WAXS/SAXS experiments during tensile deformation are entirely consistent with our previous research on PA6 at 30 °C.…”

Section: Methodsmentioning

confidence: 93%

“…As a vital affecting factor of the material properties, serious consideration is taken into temperature in experimental and industrial field. To systematically detect the temperature dependent structure evolution during uniaxial tension, we detected the structural evolution of PA6 below glass transition temperature for a start . The structure‐mechanical property relationship of PA6 above the T g , however, was not described precisely in previous reports.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Direct Observations on Structure Evolutions in Polyamide 6 during Deformation at High Temperatures with WAXS and SAXS

Guo

Wang

et al. 2019

Polymer Engineering & Sci

Self Cite

View full text Add to dashboard Cite

The deformation induced structure evolutions of polyamide 6 (PA6) during uniaxial tension at high tensile temperatures (60 °C and 90°C) were investigated with in situ wide‐ and small‐angle X‐ray scattering (WAXS and SAXS) technologies. The obtained data on structure evolutions revealed that they were different from the results measured at low temperature (30 °C). The α‐phase got oriented once upon the beginning of deformation. After yielding the γ‐phase started to be oriented following the α‐phase. While, the breakdown of PA6 crystals along a and c axis overcame partial crystalline orientation at the high tensile temperatures (60 and 90 °C). The competition between stretch of amorphous phase and slippage of lamellae after yielding affected the deformation behavior of PA6. The collapse of lamellae was also confirmed from SAXS analysis and such disrupted lamellar structure resulted in the decrease of long spacing of PA6. The results showed that PA6 materials may show higher ductility at high temperatures. Therefore the crystals could be broken more easily and the formed lamellar fragments of PA6 could be preserved at larger strain at 90 °C. In addition, the yielding of PA6 and γ‐phase orientation depended on the lamellar slippage during the deformation. POLYM. ENG. SCI., 60:581–586, 2020. © 2019 Society of Plastics Engineers

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Direct Observations on Structure Evolutions in Polyamide 6 during Deformation at High Temperatures with WAXS and SAXS

Guo

Wang

et al. 2019

Polymer Engineering & Sci

Self Cite

View full text Add to dashboard Cite

show abstract

Crystal structure, morphology, and mechanical properties of biaxially oriented polyamide‐6 films toughened with poly(ether block amide)

Lin

Cui

et al. 2021

Polymers for Advanced Techs

View full text Add to dashboard Cite

Biaxially oriented polyamide‐6 (BOPA) film has been widely used in many packaging applications. However, the BOPA film with excellent toughness is still required when utilizing in the field of soft‐packaged lithium‐ion batteries, pharmaceutical blister packaging, or frozen food packaging especially for vacuum packaging of irregular‐shaped food products. The purpose of this study was to improve the toughness of BOPA films by toughening with poly(ether block amide) (PEBA) (BOPA/PEBA films) based on the simultaneous biaxial stretching technology. The crystal structure, morphology, optical properties, barrier, and mechanical properties of BOPA/PEBA films were investigated. The results showed that the incorporation of PEBA into BOPA films slightly decreased the melting temperature and crystallinity of PA6, and the BOPA/PEBA films exhibited only α‐form crystals and no preferential orientation in the machine direction (MD) and transition direction (TD). The morphological observation showed that higher addition of PEBA led to the formation of microvoids due to the poor compatibility between PA6 and PEBA. As a result, the transmittance and oxygen barrier properties of the BOPA/PEBA films decreased. In addition, mechanical analysis suggested that the addition of PEBA could effectively improve the toughness of BOPA film.

show abstract

Phase Control of Polyamide 6 via Extension‐Dominated Polymer Blend Reactive Extrusion

Chen

Zhu

Maia

2020

Polymer Engineering & Sci

View full text Add to dashboard Cite

Control of the crystalline phase transition of polymers is critical to improve mechanical properties and to achieve good levels of thermal properties in polymer engineering. Current methods control the transition process by using thermal methods that is, annealing above the glass transition temperature (T g ) to get the targeting crystalline phase. It requires precise control of the temperature and process time and is limited to a small scale. In contrast, a novel processing-based method developed in our group by combining the use of reactive processing technique and extensional mixing elements (EME) allows different sizes of minor phase droplets in immiscible polymer blends to be achieved by controlling the degree of aggressiveness of the EME. The use of EME can confine polyamide crystalline structure into the γ-phase from the α-phase. The reactive processing benefits in stabilizing these droplets and in freezing the corresponding crystalline morphologies in droplets. Crystalline phase transition of the minor phase in these droplets is therefore observed as the size of droplet decreases from micro to submicron. Furthermore, phase transition can be precisely controlled by tuning additives and EME blocks. FIG. 7. Curves of the first cooling cycle of DSC measurements for various pellet-shaped samples with a cooling rate of 10 C/min.

show abstract

Direct investigations of deformation and yield induced structure transitions in polyamide 6 below glass transition temperature with WAXS and SAXS

Cited by 23 publications

References 45 publications

Direct Observations on Structure Evolutions in Polyamide 6 during Deformation at High Temperatures with WAXS and SAXS

Direct Observations on Structure Evolutions in Polyamide 6 during Deformation at High Temperatures with WAXS and SAXS

Crystal structure, morphology, and mechanical properties of biaxially oriented polyamide‐6 films toughened with poly(ether block amide)

Phase Control of Polyamide 6 via Extension‐Dominated Polymer Blend Reactive Extrusion

Contact Info

Product

Resources

About