In-situ analysis of fiber structure development for isotactic polypropylene

Kang, Young-Ah; Kim, KyoungHou; Ikehata, Soichiro; Ohkoshi, Yutaka; Gotoh, Yasuo; Nagura, Masanobu; Urakawa, Hiroshi

doi:10.1016/j.polymer.2011.03.005

Cited by 19 publications

(21 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The details of the in situ measurements described here can be found in our previous papers. [8][9][10][11][12][13][14] The running fiber was heated using a CO 2 laser beam generated by a PIN-20S laser source (manufactured by Onizuka Co. Ltd, Ome, Japan). The fiber was irradiated from three directions to minimize its cross-sectional temperature variation.…”

Section: Experimental Procedures Co 2 Laser Absorption Coefficientmentioning

confidence: 99%

“…X-ray diffraction data and the fiber temperature were measured as functions of elapsed time t, which was calculated from the distance X between the measurement and necking points divided by the fiber running speed v. The distance X was controlled by shifting the necking position using a traveling mirror unit, as described in the previous reports. [8][9][10][11][12][13][14] …”

Section: Experimental Procedures Co 2 Laser Absorption Coefficientmentioning

confidence: 99%

“…Additional details of the in situ WAXD measurement can be found in our previous reports. [8][9][10][11][12][13][14] The position y 0 and the half width s were determined by fitting the measurements to a Gaussian function (2). The effect of beam divergence on s was corrected using the width of the lead dioxide intensity profiles.…”

Section: Neck Drawing and Time Resolutionmentioning

confidence: 99%

“…The in situ fiber temperature measurement was conducted in the same manner as in the previous studies. [8][9][10][11][12][13][14] RESULTS AND DISCUSSION Fiber temperature To determine the change in fiber temperature during the laser-heated drawing, the fiber temperature profile as a function of distance from the necking point was obtained and is presented in Figure 2. The origin of the horizontal axis in Figure 2 designates the necking point, Figure 1 Schematic diagram of the in situ measurement system.…”

Section: Neck Drawing and Time Resolutionmentioning

confidence: 99%

“…[8][9][10][11][12][13][14] The measured parameters were determined as functions of the elapsed time, which was calculated using the distance between the measurement point and the necking position. This calculation allows good time resolution because the necking is confined to a narrow region in which CO 2 laser radiation produces rapid and uniform heating.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

Kim

Kang

Yokoyama

et al. 2012

Polym J

Self Cite

View full text Add to dashboard Cite

The structural development of poly(butylene terephthalate) (PBT) fibers was analyzed using in situ wide angle X-ray diffraction and fiber temperature measurements during CO 2 laser-heated drawing, in which the necking position on the running fiber could be fixed by CO 2 laser irradiation. The measured parameters were determined as functions of the elapsed time after necking with a time resolution of 0.3 ms. The as-spun PBT fibers, which exhibited a low-oriented a-crystalline structure, were drawn to a draw ratio of 5 using laser heating. The (001 0 ) reflection, which indicates a quasi-smectic fibrillar structure, was not observed before crystallization in contrast to measurements of poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalene dicarboxylate) (PEN). The a-crystal was transformed into an oriented b-form crystal at the necking position, and the developed b-crystallites exhibited increased size and altered orientation o2 ms after necking. The fiber temperature increased rapidly at around T g , and the rearrangement of the b-crystal primarily occurred as the fiber's temperature rose from 100 to 160 1C. Keywords: crystal-crystal transition; laser-heated drawing; poly(butylene terephthalate) INTRODUCTION Poly(butylene terephthalate) (PBT) is a type of polyester produced by the polymerization of 1,4-butanediol and terephthalic acid. PBT has two more methylene (CH 2 ) groups than poly(ethylene terephthalate) (PET), which results in reduced coherence among molecules and provides the PBT fiber with increased flexibility. The higher chain flexibility causes a reversible crystal-crystal transition, and the PBT fiber thus exhibits good stretching properties with high stretch recovery.PBT has two different crystalline forms: the a-form and the bform. 1-7 The a-form crystalline structure, in which the chain consists of four methylene groups with a gauche-trans-gauche conformation, is found in a relaxed state and is the most stable structure. The a-crystal is transformed into the b-crystal when the polymer is held under strain, and the polymer reversibly transforms to the a-crystal upon removal of the strain. The b-crystal consists of an all-trans conformation chain. This difference in conformation between the b-crystal and the a-crystal, which is not fully extended, primarily affects the unit cell parameter c, which is very sensitive to the transition and is often used to detect the transition. Mencik 1 was the first to index the unit cell of the a-crystal, which is triclinic and has

show abstract

Section: Experimental Procedures Co 2 Laser Absorption Coefficientmentioning

confidence: 99%

Section: Experimental Procedures Co 2 Laser Absorption Coefficientmentioning

confidence: 99%

Section: Neck Drawing and Time Resolutionmentioning

confidence: 99%

Section: Neck Drawing and Time Resolutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

Kim

Kang

Yokoyama

et al. 2012

Polym J

Self Cite

View full text Add to dashboard Cite

show abstract

Photodegradation of partially oriented and drawn polypropylene filaments

Mahmoodabadi

Kish

Aslanzadeh

2017

J of Applied Polymer Sci

View full text Add to dashboard Cite

The effects of fiber structure on the process of photodegradation are controversial in the field. We tested polypropylene fibers of various form for their effects on photodegradation. Fiber grade polypropylene granules were spun into partially oriented multifilament yarns at a spinning speed of 2000 m min−1. The yarns were drawn using a draw‐twist unit. Yarns were exposed to ultra‐violet radiations in a covered open air chamber for different periods of time under two different sources of emissions (UVA; λ > 300 nm and UVC; λ = 254 nm). The samples were examined by Fourier transform infrared spectroscopy, mechanical testing, differential scanning calorimetry, microscopy, and density measurements. In photodegradation process, the drawn filaments had a longer induction time than undrawn ones. The mechanical properties of the undrawn yarns deteriorate faster than the drawn yarns. During the early periods of degradation helical content increases considerably, while the density fluctuates and increases. The degradation rate under UVC radiation was faster than under UVA radiation because of the higher energy of the UVC radiation. The upper photostability of the drawn yarns compared to the undrawn ones was due to the higher crystalline fraction and greater molecular orientation in the drawn yarn. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45716.

show abstract

Structure and mechanical properties of multi-hollowed fibers produced by CO₂ laser irradiated neck drawing

et al. 2015

Self Cite

View full text Add to dashboard Cite

Multi-hollowed fibers with a hollowness ratio of over 20% were successfully produced using a neck-drawing technique accompanied by CO 2 laser irradiation on unoriented and amorphous polytrimethylene terephthalate (PTT) fibers with diameters of approximately 104 mm. The structure and mechanical properties of the multi-hollowed fibers were characterized using scanning electron microscopy, wide angle X-ray diffraction (WAXD), birefringence measurements, and tensile tests. Crystal orientation factors in the direction normal to the (010) and (002) planes, which were obtained from WAXD patterns, were lower in comparison to values obtained in previous studies on fibers that did not feature these hollows [9] because of the development of these internal hollows. The PTT fibers in this study also displayed high toughness, about 465 MPa (3.5 cN/dtex) strength and about 40% elongation, and had excellent elastic recovery (>95%) after 10 stretch cycles. POLYM. ENG. SCI., 56:609-616, 2016.

show abstract

In-situ analysis of fiber structure development for isotactic polypropylene

Cited by 19 publications

References 34 publications

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

Photodegradation of partially oriented and drawn polypropylene filaments

Structure and mechanical properties of multi-hollowed fibers produced by CO₂ laser irradiated neck drawing

Contact Info

Product

Resources

About

In-situ analysis of fiber structure development for isotactic polypropylene

Cited by 19 publications

References 34 publications

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

Photodegradation of partially oriented and drawn polypropylene filaments

Structure and mechanical properties of multi-hollowed fibers produced by CO2 laser irradiated neck drawing

Contact Info

Product

Resources

About

Structure and mechanical properties of multi-hollowed fibers produced by CO₂ laser irradiated neck drawing