1
|
Ge C, Hu R, Zhu J, Huang J, Zhang C, Zhang Y, Xing Y, Zhang B, Jiang F. Combination of chitin, lignin, and plant oil for high-performance sustainable elastomers with UV-shielding and photothermal properties. Int J Biol Macromol 2025; 306:141553. [PMID: 40032115 DOI: 10.1016/j.ijbiomac.2025.141553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2024] [Revised: 02/20/2025] [Accepted: 02/25/2025] [Indexed: 03/05/2025]
Abstract
Developing sustainable elastomers derived from natural resources is crucial to mitigate environmental pollution yet challenging on account of their limited properties. In this work, chitin, lignin, and plant oil were selected as the feedstocks to design renewable bottlebrush copolymer elastomers via homogeneous reversible addition-fragmentation chain transfer (RAFT) polymerization. In such kind of bottlebrush copolymers, chitin serves as the rigid backbone, while the plant oil-derived monomer 4-vinylbenzyl oleate (VBO) and lignin-derived monomer syringaldehyde acrylate (SA) were chosen as the soft and hard segments for the rubbery brushes, respectively. These chitin-graft-poly(4-vinylbenzyl oleate-co-syringaldehyde acrylate) (Chitin-g-P(VBO-co-SA)) bottlebrush elastomers possess tunable mechanical properties and superior UV-shielding performance. To further improve their macroscopic behavior, carbon dots (CDs) were incorporated into the Chitin-g-P(VBO-co-SA) copolymers. The resulting Chitin-g-P(VBO-co-SA)/CD composites exhibit significantly enhanced tensile strength and excellent photothermal conversion ability owing to the introduction of CDs. This robust and convenient strategy can inspire the continuous development of strong and functional sustainable elastomers by combining different natural resources.
Collapse
Affiliation(s)
- Chongxiao Ge
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Rui Hu
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Jingyan Zhu
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Jiajing Huang
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Cancan Zhang
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Yaqiong Zhang
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Yuxian Xing
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China.
| | - Bin Zhang
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; Beijing National Laboratory for Molecular Sciences (BNLMS), Beijing 100190, China.
| | - Feng Jiang
- Anhui Provincial Engineering Center for High Performance Biobased Nylons, Department of Materials Science and Engineering, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui 230036, China.
| |
Collapse
|
2
|
Hyeong J, Koo J, Rim M, Wi Y, Ko H, Yu D, Kim S, Kim N, Yoo MJ, Jeong KU. Stretchable Heat Transfer Eco-Materials: Mesogen Grafted NR-Based Nanocomposites with High Thermal Conductivity and Low Dielectric Constant. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2025; 21:e2406066. [PMID: 39221661 DOI: 10.1002/smll.202406066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/20/2024] [Indexed: 09/04/2024]
Abstract
Biomass-based functional polymers have received significant attention across various fields, in view of eco-friendly human society and sustainable growth. In this context, there are efforts to functionalize the biomass polymers for next-generation polymer materials. Here, stretchable heat transfer materials are focused on which are essential for stretchable electronics and future robotics. To achieve this goal, natural rubber (NR) is chemically modified with a thiol-terminated phenylnaphthalene (TTP), and then utilized as a thermally conductive NR (TCNR) matrix. Hexagonal boron nitride (h-BN), renowned for its high thermal conductivity and low electrical conductivity, is incorporated as a filler to develop stretchable heat transfer eco-materials. The optimized TCNR/h-BN composite elongates to 140% due to great elasticity of NR, and exhibits excellent dielectric properties (a low dielectric constant of 2.26 and a low dielectric loss of 0.006). Furthermore, synergetic phonon transfer of phenylnaphthalene crystallites and h-BN particles in the composite results in a high thermal conductivity of 0.87 W m-1 K-1. The outstanding thermal, mechanical, and dielectric properties of the newly developed TCNR/h-BN composite enable the successful demonstration as stretchable and shape-adaptable thermal management materials.
Collapse
Affiliation(s)
- Jaeseok Hyeong
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Jahyeon Koo
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Minwoo Rim
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Youngjae Wi
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Hyeyoon Ko
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Dongmin Yu
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Sanghee Kim
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Namil Kim
- Department of Chemical Engineering, Hannam University, Daejeon, 34054, Republic of Korea
| | - Myong Jae Yoo
- Electronic Convergence Materials & Device Research Center, Korea Electronics Technology Institute (KETI), Seongnam, 13509, Republic of Korea
| | - Kwang-Un Jeong
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| |
Collapse
|
3
|
Yamada S, Kajita T, Nishimoto M, Horiuchi J, Fujii Y, Sakaguchi K, Hattori K, Tamura H, Kano T, Sakai T, Noro A. Next-Generation Structural Adhesives Composed of Epoxy Resins and Hydrogen-Bonded Styrenic Block Polymer-Based Thermoplastic Elastomers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:65270-65280. [PMID: 39303009 PMCID: PMC11615847 DOI: 10.1021/acsami.4c12540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 09/10/2024] [Accepted: 09/12/2024] [Indexed: 09/22/2024]
Abstract
Structural adhesives are currently applied in the assembly of automobiles, aircraft, and buildings. In particular, epoxy adhesives are widely used due to their excellent mechanical strength and durability. However, cured epoxy resins are typically rigid and inflexible; thus, they have low peel and impact strength. In this study, tough cured epoxy adhesives were developed by mixing a liquid epoxy prepolymer (EP) and polystyrene-b-polyisoprene-b-polystyrene (SIS). SIS is a block polymer-based thermoplastic elastomer (TPE) composed of polystyrene (S) soluble in liquid EP and polyisoprene (I) insoluble in liquid EP, where S and I have a glass transition temperature that is higher and lower than room temperature, respectively. In addition, cured adhesives tougher than the cured adhesives containing SIS were prepared by mixing liquid EP and SIS with hydrogen-bonding groups in the I block (h-SIS). Transmission electron microscopy (TEM) observations revealed mixed S/cured EP domains, with a d-spacing of several tens of nanometers, and cured EP domains, with diameters of one hundred to several hundred nanometers, that were macroscopically dispersed in the I or hydrogen-bonded I matrix of the cured adhesive containing SIS or h-SIS. The lap shear, peel, and impact strength of cured neat EP (EP*) were 23 MPa, 45 N/25 mm, and 0.62 kN/m, respectively. Meanwhile, the cured adhesive containing 16.5 wt % SIS exhibited the slightly lower lap shear strength of 17 MPa compared to that of cured EP*, whereas the peel and impact strength of the cured adhesive with SIS were 61 N/25 mm and 7.1 kN/m, respectively, both higher than those of EP*. Furthermore, the lap shear strength of the cured adhesive containing 15.5 wt % h-SIS was 21 MPa, which was similar to that of cured EP*. The cured adhesive with h-SIS also exhibited an excellent peel strength of 97 N/25 mm and an impact strength of 14 kN/m which was 22 times higher than that of cured EP*. Therefore, mixing liquid EP and SIS improved the cured adhesive properties and flexibility of the cured epoxy adhesives compared to the cured adhesive composed of neat EP, and further enhancement of the adhesive properties was achieved by mixing liquid EP and h-SIS with hydrogen-bonding groups instead of mixing with SIS.
Collapse
Affiliation(s)
- Saya Yamada
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Takato Kajita
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Mio Nishimoto
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Junko Horiuchi
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Yoshirou Fujii
- Chemical
Products R&D Department, Engineering Division, Aisin Chemical Co., Ltd., 1141-1 Okawagahara, Fujioka-iino-cho, Toyota, Aichi 470-0492, Japan
| | - Kazumasa Sakaguchi
- Chemical
Products R&D Department, Engineering Division, Aisin Chemical Co., Ltd., 1141-1 Okawagahara, Fujioka-iino-cho, Toyota, Aichi 470-0492, Japan
| | - Kazuo Hattori
- Chemical
Products R&D Department, Engineering Division, Aisin Chemical Co., Ltd., 1141-1 Okawagahara, Fujioka-iino-cho, Toyota, Aichi 470-0492, Japan
| | - Hiroshi Tamura
- Chemical
Products R&D Department, Engineering Division, Aisin Chemical Co., Ltd., 1141-1 Okawagahara, Fujioka-iino-cho, Toyota, Aichi 470-0492, Japan
| | - Tatsuya Kano
- Chemical
Products R&D Department, Engineering Division, Aisin Chemical Co., Ltd., 1141-1 Okawagahara, Fujioka-iino-cho, Toyota, Aichi 470-0492, Japan
| | - Takenobu Sakai
- Promotion
Office for Open Innovation, Institutes of
Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
- Institute
of Materials Innovation, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Atsushi Noro
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
- Institute
of Materials Innovation, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
- Research
Center for Net-Zero Carbon Society, Institutes of Innovation for Future
Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| |
Collapse
|
4
|
Poon KC, Gregory GL, Sulley GS, Vidal F, Williams CK. Toughening CO 2 -Derived Copolymer Elastomers Through Ionomer Networking. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302825. [PMID: 37201907 DOI: 10.1002/adma.202302825] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/04/2023] [Indexed: 05/20/2023]
Abstract
Utilizing carbon dioxide (CO2 ) to make polycarbonates through the ring-opening copolymerization (ROCOP) of CO2 and epoxides valorizes and recycles CO2 and reduces pollution in polymer manufacturing. Recent developments in catalysis provide access to polycarbonates with well-defined structures and allow for copolymerization with biomass-derived monomers; however, the resulting material properties are underinvestigated. Here, new types of CO2 -derived thermoplastic elastomers (TPEs) are described together with a generally applicable method to augment tensile mechanical strength and Young's modulus without requiring material re-design. These TPEs combine high glass transition temperature (Tg ) amorphous blocks comprising CO2 -derived poly(carbonates) (A-block), with low Tg poly(ε-decalactone), from castor oil, (B-block) in ABA structures. The poly(carbonate) blocks are selectively functionalized with metal-carboxylates where the metals are Na(I), Mg(II), Ca(II), Zn(II) and Al(III). The colorless polymers, featuring <1 wt% metal, show tunable thermal (Tg ), and mechanical (elongation at break, elasticity, creep-resistance) properties. The best elastomers show >50-fold higher Young's modulus and 21-times greater tensile strength, without compromise to elastic recovery, compared with the starting block polymers. They have wide operating temperatures (-20 to 200 °C), high creep-resistance and yet remain recyclable. In the future, these materials may substitute high-volume petrochemical elastomers and be utilized in high-growth fields like medicine, robotics, and electronics.
Collapse
Affiliation(s)
- Kam C Poon
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Georgina L Gregory
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Gregory S Sulley
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Fernando Vidal
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Charlotte K Williams
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| |
Collapse
|
5
|
Aiswarya S, Awasthi P, Banerjee SS. Self-healing thermoplastic elastomeric materials: Challenges, opportunities and new approaches. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
6
|
The Dynamic Properties at Elevated Temperature of the Thermoplastic Polystyrene Matrix Modified with Nano-Alumina Powder and Thermoplastic Elastomer. Polymers (Basel) 2022; 14:polym14163319. [PMID: 36015576 PMCID: PMC9413512 DOI: 10.3390/polym14163319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/06/2022] [Accepted: 08/12/2022] [Indexed: 11/22/2022] Open
Abstract
The performance improvement of advanced electronic packaging material is an important topic to meet the stringent demands of modern semiconductor devices. This paper studies the incorporation of nano-alumina powder and thermoplastic elastomer (TPE) into thermoplastic polystyrene matrix to tune the thermal and mechanical properties after injection molding process. In the sample preparation, acetone was employed as a solvent to avoid the powder escape into surrounding during the mechanical mixing in a twin-screw mixer. The pressure and shear force were able to mix the composite with good uniformity in compositions. The samples with different compositions were fabricated using injection molding. The measured results showed that adding 5 wt.% of TPE into the simple polystyrene was able to raise the melt flow index from 12.3 to 13.4 g/10 min while the thermal decomposition temperature remained nearly unchanged. Moreover, the addition of small amount of nano-alumina powder could quickly improve the mechanical property by raising its storage modulus. For example, the addition of 3 wt.% of nano-alumina powder had an increase of 7.3% in storage modulus. Over doping of nano-alumina powder in the composite, such as 10 wt.%, on the other hand, lowered the storage modulus from 2404 MPa to 2069 MPa. The experimental study demonstrated that the tuning in the polystyrene’s thermal and mechanical properties is feasible by composition modification with nano-alumina powder and TPE. The better concentration of the additives should be determined according to the specific applications.
Collapse
|
7
|
Gregory GL, Williams CK. Exploiting Sodium Coordination in Alternating Monomer Sequences to Toughen Degradable Block Polyester Thermoplastic Elastomers. Macromolecules 2022; 55:2290-2299. [PMID: 35558439 PMCID: PMC9084597 DOI: 10.1021/acs.macromol.2c00068] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/14/2022] [Indexed: 01/26/2023]
Abstract
![]()
Thermoplastic
elastomers (TPEs) that are closed-loop recyclable
are needed in a circular material economy, but many current materials
degrade during recycling, and almost all are pervasive hydrocarbons.
Here, well-controlled block polyester TPEs featuring regularly placed
sodium/lithium carboxylate side chains are described. They show significantly
higher tensile strengths than unfunctionalized analogues, with high
elasticity and elastic recovery. The materials are prepared using
controlled polymerizations, exploiting a single catalyst that switches
between different polymerization cycles. ABA block polyesters of high
molar mass (60–100 kg mol–1; 21 wt % A-block)
are constructed using the ring-opening polymerization of ε-decalactone
(derived from castor oil; B-block), followed by the alternating ring-opening
copolymerization of phthalic anhydride with 4-vinyl-cyclohexene oxide
(A-blocks). The polyesters undergo efficient functionalization to
install regularly placed carboxylic acids onto the A blocks. Reacting
the polymers with sodium or lithium hydroxide controls the extent
of ionization (0–100%); ionized polymers show a higher tensile
strength (20 MPa), elasticity (>2000%), and elastic recovery (>80%).
In one case, sodium functionalization results in 35× higher stress
at break than the carboxylic acid polymer; in all cases, changing
the quantity of sodium tunes the properties. A leading sample, 2-COONa75 (Mn 100 kg mol–1, 75% sodium), shows a wide operating temperature range (−52
to 129 °C) and is recycled (×3) by hot-pressing at 200 °C,
without the loss of mechanical properties. Both the efficient synthesis
of ABA block polymers and precision ionization in perfectly alternating
monomer sequences are concepts that can be generalized to many other
monomers, functional groups, and metals. These materials are partly
bioderived and have degradable ester backbone chemistries, deliver
useful properties, and allow for thermal reprocessing; these features
are attractive as future sustainable TPEs.
Collapse
Affiliation(s)
- Georgina L. Gregory
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Charlotte K. Williams
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| |
Collapse
|
8
|
Kajita T, Noro A, Oda R, Hashimoto S. Highly Impact-Resistant Block Polymer-Based Thermoplastic Elastomers with an Ionically Functionalized Rubber Phase. ACS OMEGA 2022; 7:2821-2830. [PMID: 35097278 PMCID: PMC8793043 DOI: 10.1021/acsomega.1c05609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
There has been a great deal of interest in incorporating noncovalent bonding groups into elastomers to achieve high strength. However, the impact resistance of such elastomers has not been evaluated, even though it is a crucial mechanical property in practical usage, partly because a large-scale synthetic scheme has not been established. By ionizing the rubber component in polystyrene-b-polyisoprene-b-polystyrene (SIS), we prepared several tens of grams of SIS-based elastomers with an ionically functionalized rubber phase and a sodium cation (i-SIS(Na)) or a bulky barium cation (i-SIS(Ba)). The i-SIS(Na) and i-SIS(Ba) exhibited very high tensile toughness of 520 and 280 MJ m-3, respectively. They also exhibited excellent compressive resistance. Moreover, i-SIS(Ba) was demonstrated to have a higher impact resistance, that is, more protective of a material being covered compared to covering by typical high-strength glass fiber-reinforced plastic. As such elastomers can be produced at an industrial scale, they have great market potential as next-generation elastomeric materials.
Collapse
Affiliation(s)
- Takato Kajita
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Atsushi Noro
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
- Institute
of Materials Innovation, Institutes of Innovation for Future Society, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya 464-8601, Japan
| | - Ryoji Oda
- Zeon
Corporation, 1-6-2 Marunouchi, Chiyoda-ku, Tokyo 100-8246, Japan
| | | |
Collapse
|
9
|
Liu B, Chen X, Spiering GA, Moore RB, Long TE. Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block. Molecules 2021; 26:molecules26154705. [PMID: 34361857 PMCID: PMC8348091 DOI: 10.3390/molecules26154705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.
Collapse
Affiliation(s)
- Boer Liu
- Biodesign Center for Sustainable Macromolecular Materials and Manufacturing, School of Molecular Sciences, Arizona State University, Tempe, AZ 85281, USA;
| | - Xi Chen
- Department of Chemistry, Macromolecules Innovation Institute (MII), Virginia Tech, Blacksburg, VA 24061, USA; (X.C.); (G.A.S.); (R.B.M.)
| | - Glenn A. Spiering
- Department of Chemistry, Macromolecules Innovation Institute (MII), Virginia Tech, Blacksburg, VA 24061, USA; (X.C.); (G.A.S.); (R.B.M.)
| | - Robert B. Moore
- Department of Chemistry, Macromolecules Innovation Institute (MII), Virginia Tech, Blacksburg, VA 24061, USA; (X.C.); (G.A.S.); (R.B.M.)
| | - Timothy E. Long
- Biodesign Center for Sustainable Macromolecular Materials and Manufacturing, School of Molecular Sciences, Arizona State University, Tempe, AZ 85281, USA;
- Correspondence:
| |
Collapse
|