Recent progress in block copolymer crystallization

Horn, Ryan M. Van; Steffen, Maxwell R.; O'Connor, Dana

doi:10.1002/pcr2.10039

Cited by 27 publications

(34 citation statements)

References 276 publications

(871 reference statements)

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“…Diblock copolymers can exhibit a variety of morphologies depending on the segregation strength and on some key temperatures as will be explained in more detail in the next section. The crystallization of block copolymers has attracted much attention [33,[76][77][78][79][80][81][82][83][84][85][86][87][88][89], and fractionated crystallization [33,78,79,84,86,90] has been reported for strongly segregated block copolymers, as well as for weakly segregated or miscible block copolymers, some of the results reported in literature can be found in the following table (Table 3).…”

Section: Block Copolymersmentioning

confidence: 99%

Fractionated crystallization in semicrystalline polymers

Sangroniz

Wang

et al. 2021

Progress in Polymer Science

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The crystallization of heterogeneously nucleated bulk polymers typically occurs in a single exothermic process, within a narrow temperature range, i.e., a single exothermic peak is detected by Differential Scanning Calorimetry when the material is cooled from the melt. However, when a bulk semicrystalline polymer is subdivided or dispersed into a multitude of totally (or partially) isolated microdomains (e.g., droplets or cylinders), in number comparable to that of commonly available nucleating heterogeneities, several separated crystallization events are typically observed, i.e., fractionated crystallization. This situation is often found for the minor crystallizable component in immiscible blends.When the bulk polymer is dispersed into a number of microdomains that is several orders of magnitude higher than the available number of heterogeneities within it, most microdomains will be heterogeneity-free. In these clean microdomains the nucleation can occur by contact with the interfaces (i.e., surface nucleation) or by homogeneous nucleation inside the microdomain volume. These cases can be easily encountered in cylinders or spheres within strongly segregated block copolymers, or in infiltrated polymers within nanopores of alumina templates.In this work, a comprehensive review of the known cases of fractionated crystallization is provided. The changes upon decreasing microdomain sizes from a dominant single heterogeneous nucleation, through fractionated crystallization, to surface or homogeneous nucleation are critically reviewed. Emphasis is placed on the common features of the phenomenon across the different systems, and thus on the general conclusions that can be drawn from the analysis of representative semicrystalline polymers. The origin of the fractionated crystallization effects and their dramatic consequences on the nucleation and crystallization kinetics of semicrystalline polymers are also discussed.

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Section: Block Copolymersmentioning

confidence: 99%

Fractionated crystallization in semicrystalline polymers

Sangroniz

Wang

et al. 2021

Progress in Polymer Science

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“…Although the thermal and crystallization properties of PCL, PLA, their blends and their copolymers have been extensively studied, there is a great need to improve the thermal and mechanical properties of PCL and PLA to increase their scope of applications in the biomedical or environmental plastics fields. One of the most effective methods for enhancing these properties is copolymerization with other monomers or polymers . Polydimethylsiloxane (PDMS) is an extremely interesting material since it possesses many attractive properties compared to other polymeric materials.…”

Section: Introductionmentioning

confidence: 99%

Influence of semi‐crystalline poly(ε‐caprolactone) and non‐crystalline polylactide blocks on the thermal properties of polydimethylsiloxane‐based block copolymers

Brogly

Bistac

Delaite

et al. 2020

Polymer International

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Poly(A)-block-poly(B), poly(A)-block-poly(B)-block-poly(A) and B(A) 2 block copolymers were prepared through coordinated anionic ring-opening polymerization of ε-caprolactone (CL) and lactic acid (LA) using hydroxy-terminated polydimethylsiloxane (PDMS) as initiator. A wide range of well-defined combinations of PDMS-block-PCL and PDMS-block-PLA diblock copolymers, PCL-block-PDMS-block-PCL and PLA-block-PDMS-block-PLA triblock copolymers and star-PDMS(PCL) 2 copolymers were thus obtained. The number-average molar masses and the structure of the synthesized block copolymers were identified using various analytical techniques. The thermal properties of these copolymers were established using differential scanning calorimetry. Considering PDMS-block-PCL copolymers, the results demonstrate the complex effect of polymer architecture and PCL block length on the ability of the PDMS block to crystallize or not. In the case of diblock copolymers, crystallization of PCL blocks originated from stacking of adjacent chains inducing the extension of the PDMS block that can easily crystallize. In the case of star copolymers, the same tendency as in triblock copolymers is observed, showing a limited crystallization of PDMS when the length of the PCL block increases. In the case of PDMS-block-PLA copolymers, melting and crystallization transitions of the PLA block are never observed. Considering the diblock copolymers, PDMS sequences have the ability to crystallize.

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“…11 Each block of a copolymer can be either amorphous or semi-crystalline, resulting in three possibilities for diblock copolymers: crystallinecrystalline, amorphous-amorphous, or amorphous-crystalline. [12][13][14] Much research has been done on crystallization of amorphouscrystalline block copolymers, and an increasing amount is being done on the comparatively complicated crystallization processes of crystalline-crystalline block copolymers. 12 Fundamental understanding of crystallinity and the crystallization process in crystallinecrystalline block copolymers is essential in tailoring them for a specific use.…”

Section: Introductionmentioning

confidence: 99%

“…Drug permeability, 15 biodegradability, 6,16 and mechanical properties of polymer films depend heavily on crystallinity. The block crystallization order determines the macromolecular structure 12,14 and much of the properties of the end material. Relative block melting temperature (Tm), 12 relative block molecular weight or weight fraction (wblock), [17][18][19][20] and solvent interaction [21][22] are some factors that affect block crystallization.…”

Section: Introductionmentioning

confidence: 99%