Controlling Morphology Using Low Molar Mass Nucleators

Mitchell, Geoffrey R.; Wangsoub, Supatra; Nogales, Aurora; Davis, Fred J.; Olley, R. H.

doi:10.1007/978-3-319-39322-3_5

Cited by 4 publications

(10 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The |Q| value for the maximum is ~0.0325 Å −1 , corresponding to a long period of ~195 Å. This confirms observations made previously that the DBS directs the lamellar growth direction but does not otherwise change the lamellar characteristics [ 7 , 26 ]. There is also a horizontal streak on the equatorial section which was not present in the patterns recorded for the PCL and PCL/PVB samples.…”

Section: Resultssupporting

confidence: 88%

“…The addition of nucleating agents to polymers may be used to control the crystal structure as in the case of β-nucleating agents for isotactic polypropylene [ 35 ], to control of the spherulite size in packaging films [ 12 ] and in general the addition of nucleating agents leads to stiffer products [ 12 ]. We have shown in a series of papers how nucleating agents can be exploited to provide a common orientation of row nuclei to generate structures with a common lamellar crystal orientation [ 5 , 7 , 24 ]. Figure 6 shows the geometry of this process.…”

Section: Discussionmentioning

confidence: 99%

“…In a variety of solvents including polymers at very low concentrations, <1% w / w , it self-assembles into extended crystalline nanofibrils. When DBS is dispersed in a polymer matrix, the application of modest shear flow leads to a macroscopic alignment of the fibrils [ 5 , 6 , 7 ]. When the matrix is a crystallisable polymer, subsequent crystallisation of the matrix is templated by the DBS nanofibrils [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

“…Key factors with regard to dibenzylidene sorbitol enabling the direction of crystallisation are the formation of highly anisotropic nanoparticles which easily align in low shear flow field [ 7 ]. The solubility of dibenzylidene sorbitol in a polymer melt is strongly related to the polarity of the solvent as has been shown with low molar mass solvents [ 7 ]. Previous work has shown the nucleating effect of dibenzylidene sorbitol in poly(ε-caprolactone) saturates at 3% whereas in polyethylene the effect saturates at ~1% [ 6 ].The difference is related to the solubility of the dibenzylidene sorbitol in the polymeric solvent and therefore how many nanoparticles are formed to direct the crystallization.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Orthogonal Templating Control of the Crystallisation of Poly(ε-Caprolactone)

Mitchell

Olley

2018

Polymers

View full text Add to dashboard Cite

Abstract:The crystal growth of poly(ε-caprolactone) can be very effectively directed through the use of small amounts of dibenzylidene sorbitol in conjunction with modest flow fields to yield extremely high levels of the preferred polymer crystal orientation. We show that by introducing small quantities of a terpolymer, based on polyvinyl butyral we can switch the symmetry axis of the final lamellar orientation from parallel to perpendicular to the melt flow direction. During shear flow of the polymer melt, the dibenzylidene sorbitol forms highly extended nanoparticles which adopt a preferred alignment with respect to the flow field and on cooling, polymer crystallisation is directed by these particles. The presence of the terpolymer, based on polyvinyl butyral, limits the aspect ratio of the dibenzylidene sorbitol (DBS) particles, such that the preferred orientation of the particles in the polymer melt changes from parallel to normal to the flow direction. The alignment of lamellar crystals perpendicular to the flow direction has important implications for applications such as scaffolds for tissue engineering and for barrier film properties.

show abstract

Section: Resultssupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Orthogonal Templating Control of the Crystallisation of Poly(ε-Caprolactone)

Mitchell

Olley

2018

Polymers

View full text Add to dashboard Cite

show abstract

“…Generally, incorporation of β-nucleating agents (β-NAs) is the most feasible industrial way to boost the number of β-crystals and enhance the toughness of PP products. 6−8…”

Section: Introductionmentioning

confidence: 99%

Toward Subtle Manipulation of Fine Dendritic β-Nucleating Agent in Polypropylene

Wen

Nie

et al. 2017

ACS Omega

View full text Add to dashboard Cite

Dendritic β-nucleating agent (β-NA) can readily manipulate the formation of dendritic β-crystal with a unique toughening effect on polypropylene (PP) to drastically enhance the ductility. However, by the current method, the geometric size is too large to fully perform the nucleating efficiency. In this study, by comparatively investigating the effect of molecular weight of PP and diffusion of β-NAs in a PP melt, we proposed a novel carrier strategy that selective enrichment of β-NAs in a PP carrier was followed by directed migration into polymer matrix. Accordingly, the growth of NAs was controlled by the release from the PP carrier, which decreased the available amount of β-NAs during the growth stage. In this case, the viscosity difference between PP carrier and matrix determined the interfacial movement of β-NAs. When the PP carrier and matrix had same molecular weight, the diffusion and release became favorable to facilitate the formation of the dense and fine dendritic aggregates. As a result, the relative content of β-crystals reached 92%, with a drastic increase of ∼82% in the optimal condition compared to the directed compounded PP/β-NAs sample. This study can open a new avenue to tailor the topologies of β-NAs and the ensuing β-crystals for high-performance PP products.

show abstract

Controlling the Morphology of Polymers

Mitchell¹,

Tojeira²

2016

View full text Add to dashboard Cite

Controlling Morphology Using Low Molar Mass Nucleators

Cited by 4 publications

References 26 publications

Orthogonal Templating Control of the Crystallisation of Poly(ε-Caprolactone)

Orthogonal Templating Control of the Crystallisation of Poly(ε-Caprolactone)

Toward Subtle Manipulation of Fine Dendritic β-Nucleating Agent in Polypropylene

Controlling the Morphology of Polymers

Contact Info

Product

Resources

About