Generating Triple Crystalline Superstructures in Melt Miscible PEO‐<i>b</i>‐PCL‐<i>b</i>‐PLLA Triblock Terpolymers by Controlling Thermal History and Sequential Crystallization

Palacios, Jordana K.; Liu, Guoming; Wang, Dujin; Hadjichristidis, Nikos; Müller, Alejandro J.

doi:10.1002/macp.201900292

Cited by 12 publications

(16 citation statements)

References 90 publications

(188 reference statements)

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“…To that purpose, model triblock terpolymers of PLLA, PCL, and PEO blocks (PEOb-PCL-b-PLLA) have been exhaustively studied. 4,[33][34][35][36] Particularly, the morphology of these melt miscible and triple crystalline triblock terpolymers have been reported by Chiang et al 37 and Palacios et al 33,35,36 Wide-angle X-Ray scattering (WAXS) measurements, carried out during cooling, confirmed that the PLLA block is the one that crystallizes first, followed by the PCL and lastly, the PEO. PLOM observations indicated that the microscale structure is templated by the PLLA block as a result of its crystallization.…”

Section: Introductionmentioning

confidence: 67%

“…The PEO-b-PCL-b-PLLA is a triblock terpolymer with an alternating superstructure of three crystalline phases, as we had reported in previous publications. 4,[33][34][35][36] The PLLA block ) was employed as a single catalyst. For more details on the synthesis procedure and characterization, refer to 60,61 , and the references in them.…”

Section: Introductionmentioning

confidence: 99%

“…The samples under study are listed in Table 1, with composition of the blocks as subscript numbers and molecular weights of the entire diblock copolymer and terpolymer as superscript numbers. The melting points of each component determined by DSC previously [33][34][35][36] are also given in Table 1. *The melting point values reported here are a range because they depend on previous thermal history (controlled cooling or isothermal crystallization) and scanning rates employed during their determination (1, 5 or 20 ºC/min) [33][34][35][36] Films Preparation.…”

Section: Introductionmentioning

confidence: 99%

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Direct identification of three crystalline phases in PEO-b-PCL-b-PLLA triblock terpolymer by In situ hot-stage atomic force microscopy

Palacios

Zhang

et al. 2020

Polymer

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In this work, we provide a detailed description of the tri-lamellar nanoscale morphology of a triple crystalline PEO-b-PCL-b-PLLA triblock terpolymer obtained by Hot-Stage Atomic Force microscopy (AFM) imaging and Wide Angle X-ray scattering (WAXS) analysis for the first time. The precursor PCL-b-PLLA diblock copolymer has also been included in the study for comparison purposes. A two-step crystallization protocol has been applied to create a distinct lamellar morphology. Both WAXS and AFM revealed the double crystalline nature of the diblock copolymer. However, the identification of multiple crystalline phases in the triblock terpolymer by AFM and WAXS at room temperature is not straightforward. The advantages of hot-stage AFM allowed following the evolution of the lamellar morphology and the successive melting of the tricrystalline PEO-b-PCL-b-PLLA sample during heating. Taking into account the melting temperature of each crystalline block, the existing lamellar populations were clearly identified. At 45 °C, the thinnest lamellae disappeared, due to the melting of PEO crystals. The medium size lamellae disappeared at 60 °C when PCL crystals melt. At that temperature, the only remaining crystals are those of the PLLA block. AFM mechanical modulus images provide further evidence of the lamellar self-assembly of the triblock terpolymer. The nanoscale arrangement includes lamellae of PCL, PEO, or both in between the PLLA lamellae. Hot-Stage AFM is a valuable technique to elucidate the morphological features of complex multi-crystalline systems.

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Section: Introductionmentioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Direct identification of three crystalline phases in PEO-b-PCL-b-PLLA triblock terpolymer by In situ hot-stage atomic force microscopy

Palacios

Zhang

et al. 2020

Polymer

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“…The addition of a third potentially crystallizable block to diblock copolymers results in a more complex analysis of the crystallization behavior. Few studies have been published about tricrystalline triblock terpolymers, such as ABC-type triblock terpolymers and ABCBA pentablock terpolymers, including the apolar PE block, and the polar PEO, PCL, and PLLA blocks [ 17 , 24 , 37 , 42 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 ].…”

Section: Introductionmentioning

confidence: 99%

“…Palacios et al studied the crystallization and morphology of ABC triblock terpolymers with three crystallizable blocks: PEO, PCL, and PLLA [ 92 , 93 , 94 , 95 ]. They [ 92 ] highlighted the triple crystalline nature of the PEO- b -PCL- b -PLLA triblock terpolymer, with the three different blocks crystallizing independently upon cooling from the melt.…”

Section: Introductionmentioning

confidence: 99%

Crystallization and Morphology of Triple Crystalline Polyethylene-b-poly(ethylene oxide)-b-poly(ε-caprolactone) PE-b-PEO-b-PCL Triblock Terpolymers

et al. 2021

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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.

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Single crystals and two‐dimensional crystalline assemblies of block copolymers

Yang

2022

Journal of Polymer Science

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Block copolymer single crystals (BCPSCs) have attracted widespread attentions due to their unique two-dimensional (2D) structure, good controllability, and great potential applications in recent years. In this paper, the morphology, surface structure of BCPSCs and the related influencing factors are reviewed. We also summarize the studies of 2D crystalline assemblies of block copolymers (BCPs) driven by crystallization and intermolecular π-π interaction. Moreover, the functionalization and properties of BCPSCs and 2D crystalline assemblies of BCPs are introduced. Finally, we put forward some unsolved problems in this field.

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Generating Triple Crystalline Superstructures in Melt Miscible PEO‐b‐PCL‐b‐PLLA Triblock Terpolymers by Controlling Thermal History and Sequential Crystallization

Cited by 12 publications

References 90 publications

Direct identification of three crystalline phases in PEO-b-PCL-b-PLLA triblock terpolymer by In situ hot-stage atomic force microscopy

Direct identification of three crystalline phases in PEO-b-PCL-b-PLLA triblock terpolymer by In situ hot-stage atomic force microscopy

Crystallization and Morphology of Triple Crystalline Polyethylene-b-poly(ethylene oxide)-b-poly(ε-caprolactone) PE-b-PEO-b-PCL Triblock Terpolymers

Single crystals and two‐dimensional crystalline assemblies of block copolymers

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