Poly(CL/DLLA-b-CL) multiblock copolymers as biodegradable thermoplastic elastomers

Influence of e-beam irradiation on the chemical and crystal structure of poly(aliphatic/aromatic-ester) multiblock thermoplastic elastomers Poly(aliphatic/aromatic-ester) (PED) multiblock copolymers belong to the class of thermoplastic elastomers (TPEs), characterized by a physical network of semi-crystalline hard segments. The PEDs were modified with e-beam to create an additional network structure. Polymers were evaluated using SEC, WAXS, DSC and quasi-static tensile tests. E-beam irradiation induced a significant increase of molecular weight and tensile strength of the PEDs. This effect, together with the diminished degree of crystallinity can be explained by the formation of chemical crosslinks, which are located in the hard phase segments.

Download Full-text

Morphological studies of linear (AB)n multiblock copolymers and their blends

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122320 ◽

1992 ◽

Vol 50 (1) ◽

pp. 384-385

Author(s):

Richard J. Spontak ◽

Steven D. Smith ◽

Arman Ashraf

Keyword(s):

Electron Microscopy ◽

Microphase Separation ◽

Multiblock Copolymers ◽

First Order ◽

Morphological Studies ◽

Transmission Electron ◽

First Order Phase Transition ◽

Covalently Bonded ◽

Total Molecular Weight ◽

First Order Phase

Block copolymers are composed of sequences of dissimilar chemical moieties covalently bonded together. If the block lengths of each component are sufficiently long and the blocks are thermodynamically incompatible, these materials are capable of undergoing microphase separation, a weak first-order phase transition which results in the formation of an ordered microstructural network. Most efforts designed to elucidate the phase and configurational behavior in these copolymers have focused on the simple AB and ABA designs. Few studies have thus far targeted the perfectly-alternating multiblock (AB)n architecture. In this work, two series of neat (AB)n copolymers have been synthesized from styrene and isoprene monomers at a composition of 50 wt% polystyrene (PS). In Set I, the total molecular weight is held constant while the number of AB block pairs (n) is increased from one to four (which results in shorter blocks). Set II consists of materials in which the block lengths are held constant and n is varied again from one to four (which results in longer chains). Transmission electron microscopy (TEM) has been employed here to investigate the morphologies and phase behavior of these materials and their blends.

Download Full-text

Super2- Structures in Polydisperse Multiblock-Copolymers

Journal de Physique II ◽

10.1051/jp2:1997197 ◽

1997 ◽

Vol 7 (10) ◽

pp. 1489-1497 ◽

Cited By ~ 2

Author(s):

A. N. Semenov

Keyword(s):

Multiblock Copolymers

Download Full-text

Thermoplastic elastomers. Nomenclature and abbreviated terms

10.3403/30293921 ◽

2014 ◽

Keyword(s):

Thermoplastic Elastomers

Download Full-text

Thermoplastic Elastomers

Ullmann's Encyclopedia of Industrial Chemistry ◽

10.1002/14356007.a26_633 ◽

2000 ◽

Cited By ~ 1

Author(s):

Sabet Abdou-Sabet ◽

Hans-Georg Wussow ◽

Larry M. Ryan ◽

Lawrence Plummer ◽

Didier Judas ◽

...

Keyword(s):

Thermoplastic Elastomers

Download Full-text

Optical, Structural, and Dielectric Properties of Composites Based on Thermoplastic Polymers of the Polyolefin and Polyurethane Type and BaTiO3 Nanoparticles

Materials ◽

10.3390/ma14040753 ◽

2021 ◽

Vol 14 (4) ◽

pp. 753

Author(s):

M. Baibarac ◽

A. Nila ◽

I. Smaranda ◽

M. Stroe ◽

L. Stingescu ◽

...

Keyword(s):

Crystallization Process ◽

Weight Ratio ◽

Thermoplastic Elastomers ◽

Visible Spectral Range ◽

X Ray Diffraction ◽

Thermoplastic Polymers ◽

The Matrix ◽

Free Films ◽

Batio3 Nanoparticles ◽

Properties Of Composites

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.

Download Full-text

Toward Olefin Multiblock Copolymers with Tailored Properties: A Molecular Perspective

Macromolecular Theory and Simulations ◽

10.1002/mats.202100003 ◽

2021 ◽

pp. 2100003

Author(s):

Yousef Mohammadi ◽

Mohammad Reza Saeb ◽

Alexander Penlidis ◽

Esmaiel Jabbari ◽

Florian J. Stadler ◽

...

Keyword(s):

Multiblock Copolymers

Download Full-text

Synthesis, Properties, and Biodegradability of Thermoplastic Elastomers Made from 2-Methyl-1,3-propanediol, Glutaric Acid and Lactide

Life ◽

10.3390/life11010043 ◽

2021 ◽

Vol 11 (1) ◽

pp. 43

Author(s):

Lamya Zahir ◽

Takumitsu Kida ◽

Ryo Tanaka ◽

Yuushou Nakayama ◽

Takeshi Shiono ◽

...

Keyword(s):

Mechanical Properties ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Glutaric Acid ◽

Triblock Copolymers ◽

Tensile Tests ◽

Thermoplastic Elastomers ◽

Proteinase K ◽

Synthesis Properties

An innovative type of biodegradable thermoplastic elastomers with improved mechanical properties from very common and potentially renewable sources, poly(L-lactide)-b-poly(2-methyl-1,3-propylene glutarate)-b-poly(L-lactide) (PLA-b-PMPG-b-PLA)s, has been developed for the first time. PLA-b-PMPG-b-PLAs were synthesized by polycondensation of 2-methyl-1,3-propanediol and glutaric acid and successive ring-opening polymerization of L-lactide, where PMPG is an amorphous central block with low glass transition temperature and PLA is hard semicrystalline terminal blocks. The copolymers showed glass transition temperature at lower than −40 °C and melting temperature at 130–152 °C. The tensile tests of these copolymers were also performed to evaluate their mechanical properties. The degradation of the copolymers and PMPG by enzymes proteinase K and lipase PS were investigated. Microbial biodegradation in seawater was also performed at 27 °C. The triblock copolymers and PMPG homopolymer were found to show 9–15% biodegradation within 28 days, representing their relatively high biodegradability in seawater. The macromolecular structure of the triblock copolymers of PLA and PMPG can be controlled to tune their mechanical and biodegradation properties, demonstrating their potential use in various applications.

Download Full-text

Correction to Semibatch Terpolymerization of Ethylene, Propylene, and 5-Ethylidene-2-norbornene: Heterogeneous High-Ethylene EPDM Thermoplastic Elastomers

Macromolecules ◽

10.1021/acs.macromol.1c00105 ◽

2021 ◽

Vol 54 (3) ◽

pp. 1574-1574

Author(s):

Giuseppe Leone ◽

Giorgia Zanchin ◽

Rocco Di Girolamo ◽

Fabio De Stefano ◽

Christian Lorber ◽

...

Keyword(s):

Thermoplastic Elastomers ◽

Ethylene Propylene

Download Full-text