Crystallization and Morphology of Triple Crystalline Polyethylene-b-poly(ethylene oxide)-b-poly(ε-caprolactone) PE-b-PEO-b-PCL Triblock Terpolymers
| Autor: | Eider Matxinandiarena, Dario Cavallo, Agurtzane Mugica, Georgios Zapsas, Nikos Hadjichristidis, Viko Ladelta, Manuela Zubitur, Alejandro J. Müller |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Polymers and Plastics Poly(ethylene oxide) (PEO) Poly(ε-caprolactone) (PCL) Polyethylene (PE) Triblock terpolymers Tricrystalline spherulites poly(ɛ-caprolactone) (PCL) Organic chemistry 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound QD241-441 Differential scanning calorimetry law Copolymer Crystallization triblock terpolymers tricrystalline spherulites polyethylene (PE) Ethylene oxide Small-angle X-ray scattering General Chemistry Polyethylene 021001 nanoscience & nanotechnology 0104 chemical sciences 3. Good health Polymerization chemistry Chemical engineering 0210 nano-technology poly(ethylene oxide) (PEO) Caprolactone |
| Zdroj: | Polymers Volume 13 Issue 18 Addi. Archivo Digital para la Docencia y la Investigación instname Polymers, Vol 13, Iss 3133, p 3133 (2021) |
| ISSN: | 2073-4360 |
| DOI: | 10.3390/polym13183133 |
| Popis: | The morphology and crystallization behavior of two triblock terpolymers of polymethylene, equivalent to polyethylene (PE), poly (ethylene oxide) (PEO), and poly (ε-caprolactone) (PCL) are studied: PE227.1-b-PEO4615.1-b-PCL3210.4 (T1) and PE379.5-b-PEO348.8-b-PCL297.6 (T2) (superscripts give number average molecular weights in kg/mol and subscripts composition in wt %). The three blocks are potentially crystallizable, and the triple crystalline nature of the samples is investigated. Polyhomologation (C1 polymerization), ring-opening polymerization, and catalyst-switch strategies were combined to synthesize the triblock terpolymers. In addition, the corresponding PE-b-PEO diblock copolymers and PE homopolymers were also analyzed. The crystallization sequence of the blocks was determined via three independent but complementary techniques: differential scanning calorimetry (DSC), in situ SAXS/WAXS (small angle X-ray scattering/wide angle X-ray scattering), and polarized light optical microscopy (PLOM). The two terpolymers (T1 and T2) are weakly phase segregated in the melt according to SAXS. DSC and WAXS results demonstrate that in both triblock terpolymers the crystallization process starts with the PE block, continues with the PCL block, and ends with the PEO block. Hence triple crystalline materials are obtained. The crystallization of the PCL and the PEO block is coincident (i.e., it overlaps) however, WAXS and PLOM experiments can identify both transitions. In addition, PLOM shows a spherulitic morphology for the PE homopolymer and the T1 precursor diblock copolymer, while the other systems appear as non-spherulitic or microspherulitic at the last stage of the crystallization process. The complicated crystallization of tricrystalline triblock terpolymers can only be fully grasped when DSC, WAXS, and PLOM experiments are combined. This knowledge is fundamental to tailor the properties of these complex but fascinating materials. |
| Databáze: | OpenAIRE |
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