scispace - formally typeset
Journal ArticleDOI: 10.1021/ACS.MACROMOL.0C02793

Effect of Block Number and Weight Fraction on the Structure and Properties of Poly(butylene terephthalate)-block-Poly(tetramethylene oxide) Multiblock Copolymers

02 Mar 2021-Macromolecules (American Chemical Society)-Vol. 54, Iss: 6, pp 2703-2710
Abstract: We report here the influence of block number and polyester weight fraction on the properties of a series of poly(ether ester) multiblock copolymers (mBCPs), poly(butylene terephthalate)-block-poly(...

... read more

Topics: Polyester (51%)

5 results found

Journal ArticleDOI: 10.1007/S10118-021-2605-0
Yanyan Tu1, Xue-Ting Wan1, Jie Huan1, Xiang Zhu1  +2 moreInstitutions (1)
Abstract: Due to the poor solubility of aromatic polyesters in common organic solvents, trifluoroacetic acid is usually used as a co-solvent to increase their solubility for characterizations. However, only few works have reported the side reactions induced by it. We present here the application of in situ 1H-NMR techniques to explore its effect on the hydroxyl end-groups, which are usually used for the molecular weight determination of polyesters by end-group estimation method. Using bis(2-hydroxyethyl) terephthalate (BHET) as model compound, 1H quantitative NMR results show the peak integration of hydroxyethyl end-groups decreased with time via a pseudo-first-order kinetics in d-trifluoroacetic acid/d-chloroform mixture solvent (1:10, V:V). This is due to the esterification of hydroxyethyl groups with trifluoroacetic acid, revealed by the 1H-13C gradient-enhanced heteronuclear multiple bond correlation (gHMBC) spectrum. The mixtures of dimethyl terephthalate and BHET with different molar ratio were used to represent poly(ethylene terephthalate) (PET) with different degree of polymerization, and the effect of trifluoroacetic acid on the estimation of hydroxyethyl groups and subsequent molecular weight determination of polyesters was studied. Our results show that if a relative error of 5% is allowed, the NMR measurements must be finished within 1.3 h of solution preparation at 25 °C in the mixture solvent. The results were confirmed in PET sample, while in poly(ethylene adipate), the obtained esterifaction constant is faster that those in aromatic system. The results can be applied to other polymer systems with alcohol functionalized groups, and used as a guideline for the characterization of polyesters and polyethers by end-group estimation method.

... read more

Topics: Dimethyl terephthalate (62%), Trifluoroacetic acid (57%), Polyester (57%) ... show more

3 Citations

Journal ArticleDOI: 10.1039/D1PY01124C
Xue-Ting Wan1, Jian Jiang1, Yanyan Tu1, Siyuan Xu1  +7 moreInstitutions (1)
26 Oct 2021-Polymer Chemistry
Abstract: The synthesis of polyesters with the desired functional groups without additional protection and deprotection steps remains a worthwhile challenge to polymer chemists. Herein, we put forward a solution for the direct preparation of green copolyesters with versatile functionalities via the cascade polycondensation-coupling ring-opening polymerization (PROP) using a biobased cyclic diester ethylene brassylate as the monomer and functional diols/polyether diols as initiators. The combination of two polymerization processes into one system enables the facile synthesis of biodegradable polyesters with versatile functionalities, including alkane, alkene, alkyne, aromatic, halide, ether, and amide functional groups, and poly(ether ester) multiblock copolymers, together with high functional group contents (50% molar ratio to brassylate) and relatively high molecular weights (up to 6 × 104 Da). The cascade strategy provides a feasible method for the synthesis of high functional group content polyesters with tailor-made properties, highly effective for post-modifications that are suitable for a variety of applications.

... read more

Topics: Polyester (52%), Polymerization (51%)

1 Citations

Open accessJournal ArticleDOI: 10.1021/ACSSUSCHEMENG.1C06302
Zengwei Guo1, Niklas Warlin2, Smita V. Mankar2, Mohamed Sidqi3  +3 moreInstitutions (3)
Abstract: Sustainable low melting temperature bicomponent polyester fibers that can be circularly recycled were developed. The potentially biobased poly(hexamethylene terephthalate) (PHT), acting as the low ...

... read more

Topics: Polyester (51%)

Open accessJournal ArticleDOI: 10.1016/J.POLYMER.2021.124313
Jing Li1, Yanyan Tu1, Huanjun Lu1, Xiaohong Li1  +2 moreInstitutions (1)
10 Dec 2021-Polymer
Abstract: Bio-based 2,5-furandicarboxylic acid (FDCA) is a promising monomer for the substitution of fossil-based terephthalic acid, yet its condensation polymerization with corresponding diols to high quality polyesters remains challenging due to the degradation and discolouration from side reactions. We report here a cascade polycondensation-coupling ring-opening polymerization (PROP) strategy towards the rapid synthesis of poly(ethylene 2,5-furandicarboxylate)-block-poly(tetramethylene oxide) multiblock copolymers (mBCPs), (PEF-b-PTMO-b-PEF)n, via the vacuum melt polymerization of cyclic oligo(ethylene 2,5-furandicarboxylate)s (COEFs) with PTMO diols. Due to the rapid cascade polymerization, the side reactions were suppressed and poly(ether ester) mBCPs with high number-average molecular weights (Mn > 30 kg/mol) were obtained within 60 min. The segmental length, block number and soft/hard weight ratio can be well-controlled by the polymerization conditions, and their structure-property relationship was investigated. In these double-crystalline mBCPs, the melting temperature and degree of crystallinity of PEF segments increase with PEF content, while those for PTMO are less affected. These mBCPs form bicontinuous disordered phase separation morphologies, with the domain size decreases with the increment of PTMO content, the total block copolymer molecular weight, and the reduced segmental length. With the crystalline PEF domains forming the physically-crosslinking points, these mBCPs show typical thermoplastic elastomer properties with elongations exceeding 400%. The strength and Young's modulus increase with PEF content, while the elongation at break decreases. Increment of block number enhances both the strength and elongation at break for mBCPs. In addition, these sustainable mBCPs show biodegradable properties controlled by the hard/soft weight ratio and crystallinity of PEF blocks. Our cascade polymerization method provides an efficient method for the rapid preparation of sustainable high value-added thermoplastic elastomers with tailor-made properties.

... read more

Topics: Polymerization (60%), Copolymer (54%), Thermoplastic elastomer (54%) ... show more

67 results found

Open accessBook
01 Jan 1998-
Abstract: 1. Introduction 2. Melt Phase Behaviour of Block Copolymers 3. Block Copolymers in Dilute Solution 4. Block Copolymers in Semidilute and Concentrated Solutions 5. Solid State Structure of Block Copolymers 6. Blends Containing Block Copolymers Appendix: The Self Consistent Field Theory

... read more

1,606 Citations

Journal ArticleDOI: 10.1126/SCIENCE.1215368
27 Apr 2012-Science
Abstract: Advances in synthetic polymer chemistry have unleashed seemingly unlimited strategies for producing block polymers with arbitrary numbers (n) and types (k) of unique sequences of repeating units. Increasing (k,n) leads to a geometric expansion of possible molecular architectures, beyond conventional ABA-type triblock copolymers (k = 2, n = 3), offering alluring opportunities to generate exquisitely tailored materials with unparalleled control over nanoscale-domain geometry, packing symmetry, and chemical composition. Transforming this potential into targeted structures endowed with useful properties hinges on imaginative molecular designs guided by predictive theory and computer simulation. Here, we review recent developments in the field of block polymers.

... read more

773 Citations

Open accessJournal ArticleDOI: 10.1021/ACS.MACROMOL.6B02355
Christopher M. Bates1, Frank S. Bates2Institutions (2)
10 Jan 2017-Macromolecules
Abstract: Block polymers have undergone extraordinary evolution since their inception more than 60 years ago, maturing from simple surfactants to an expansive class of macromolecules encoded with exquisite attributes. Contemporary synthetic accessibility coupled with facile characterization and rigorous theoretical advances have conspired to continuously generate fundamental insights and enabling concepts that target applications spanning chemistry, biology, physics, and engineering. Here, we parse the vast literature to examine the forefront of the field and identify exciting themes and challenging opportunities that portend a bracing future trajectory. This Perspective celebrates the visionary role played by Macromolecules in advancing our understanding of this remarkable class of materials.

... read more

406 Citations