1
|
Hong JH, Mokudai H, Masaki T, Matsuno H, Tanaka K. Water-Induced Crystal Transition and Accelerated Relaxation Process of Polyamide 4 Chains in Microfibers. Biomacromolecules 2022; 23:3458-3468. [PMID: 35749630 DOI: 10.1021/acs.biomac.2c00618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microplastics have recently been identified as one of the major contributors to environmental pollution. To design and control the biodegradability of polymer materials, it is crucial to obtain a better understanding of the aggregation states and thermal molecular motion of polymer chains in aqueous environments. Here, we focus on melt-spun microfibers of a promising biodegradable plastic, polyamide 4 (PA4), with a relatively greater number density of hydrolyzable amide groups, which is regarded as an alternative to polyamide 6. Aggregation states and thermal molecular motion of PA4 microfibers without/with a post-heating drawing treatment under dry and wet conditions were examined by attenuated total reflectance-Fourier transform infrared spectroscopy and wide-angle X-ray diffraction analysis in conjunction with dynamic mechanical analysis. Sorbed water molecules in the microfibers induced the crystal transition from a meta-stable γ-form to a thermodynamically stable α-form via activation of the molecular motion of PA4 chains. Also, the post-drawing treatment caused a partial structural change of PA4 chains, from an amorphous phase to a crystalline phase. These findings should be useful for designing PA4-based structural materials applicable for use in marine environments.
Collapse
Affiliation(s)
- Jin-Hyeok Hong
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Haruki Mokudai
- Central Research Laboratories, Kureha Corporation, Fukushima 974-8686, Japan
| | - Takashi Masaki
- Central Research Laboratories, Kureha Corporation, Fukushima 974-8686, Japan
| | - Hisao Matsuno
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan.,Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan.,Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| |
Collapse
|
2
|
Taneda H, Yamada NL, Nemoto F, Minagawa Y, Matsuno H, Tanaka K. Modification of a Polymer Surface by Partial Swelling Using Nonsolvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14941-14949. [PMID: 34904431 DOI: 10.1021/acs.langmuir.1c02852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface modification without changing the physical properties in the bulk is of pivotal importance for the development of polymers as devices. We recently proposed a simple surface functionalization method for polymer films by partial swelling using a nonsolvent and demonstrated the incorporation of poly(2-methoxyethyl acrylate) (PMEA), which has an excellent antibiofouling ability, only into the outermost region of a poly(methyl methacrylate) (PMMA) film. We here extend this technology to another versatile polymer, polystyrene (PS). In this case, PS and PMEA have different solubility parameters making it difficult to select a suitable solvent, which is a nonsolvent for PS and a good solvent for PMEA, unlike the combination of PMMA with PMEA. Thus, such a solvent was first sought by examining the swelling behavior of PS films in contact with various alcohols. Once a mixed solvent of methanol/1-butanol (50/50 (v/v)) was chosen, PMEA chains could be successfully incorporated at the outermost region of the PS film. Atomic force microscopy in conjunction with neutron reflectivity revealed that chains of PMEA incorporated in the PS surface region were well swollen in water. This leads to an excellent ability to suppress the adhesion of platelets on the PS film.
Collapse
Affiliation(s)
- Hidenobu Taneda
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Norifumi L Yamada
- Neutron Science Laboratory, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai, Naka-gun, Ibaraki 319-1106, Japan
| | - Fumiya Nemoto
- Neutron Science Laboratory, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai, Naka-gun, Ibaraki 319-1106, Japan
| | - Yasuhisa Minagawa
- Sumitomo Rubber Industries, Ltd., 2-1-1 Tsutsui-cho, Chuo-ku, Kobe 651-0071, Japan
| | - Hisao Matsuno
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| |
Collapse
|