Next Article in Journal
Toxic Combustion Product Yields as a Function of Equivalence Ratio and Flame Retardants in Under-Ventilated Fires: Bench-Large-Scale Comparisons
Next Article in Special Issue
Olefin–Styrene Copolymers
Previous Article in Journal
Evaluation of FRP Confinement Models for Substandard Rectangular RC Columns Based on Full-Scale Reversed Cyclic Lateral Loading Tests in Strong and Weak Directions
Previous Article in Special Issue
Polybenzoxazine/Polyhedral Oligomeric Silsesquioxane (POSS) Nanocomposites
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessReview
Polymers 2016, 8(9), 329; doi:10.3390/polym8090329

Cracks in Polymer Spherulites: Phenomenological Mechanisms in Correlation with Ring Bands

Department of Chemical Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701-01, Taiwan
*
Author to whom correspondence should be addressed.
Academic Editor: Alexander Böker
Received: 18 July 2016 / Revised: 24 August 2016 / Accepted: 30 August 2016 / Published: 2 September 2016
(This article belongs to the Collection Featured Mini Reviews in Polymer Science)
View Full-Text   |   Download PDF [24685 KB, uploaded 2 September 2016]   |  

Abstract

This article reviews possible mechanisms of various crack forms and their likely correlations with interior crystal lamellae and discontinuous interfaces in spherulites. Complex yet periodically repetitive patterns of cracks in spherulites are beyond attributions via differences in thermal expansion coefficients, which would cause random and irregular cracks in the contract direction only. Cracks in brittle polymers such as poly(l-lactic acid) (PLLA), or poly(4-hydroxyl butyrate) (PHB), or more ductile polymers such as poly(trimethylene terephthalate) (PTT) are examined and illustrated, although for focus and demonstration, more discussions are spent on PLLA. The cracks can take many shapes that bear extremely striking similarity to the ring-band or lamellar patterns in the same spherulites. Crack patterns may differ significantly between the ring-banded and ringless spherulites, suggesting that the cracks may be partially shaped and governed by interfaces of lamellae and how the lamellar crystals assemble themselves in spherulites. Similarly, with some exceptions, most of the cracks patterns in PHB or PTT are also highly guided by the lamellar assembly in either ring-banded spherulites or ringless spherulites. Some exceptions of cracks in spherulites deviating from the apparent crystal birefringence patterns do exist; nevertheless, discontinuous interfaces in the initial lamellae neat the nuclei center might be hidden by top crystal over-layers of the spherulites, which might govern crack propagation. View Full-Text
Keywords: crack patterns; PLLA; ring-banded spherulites crack patterns; PLLA; ring-banded spherulites
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Woo, E.M.; Lugito, G. Cracks in Polymer Spherulites: Phenomenological Mechanisms in Correlation with Ring Bands. Polymers 2016, 8, 329.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top