Effect of Alkyl Chain Length in POSS Nanocage on Non-Isothermal Crystallization Behavior of PCL/Amino-POSS Nanocomposites.

Fernández Fernández,Ramos Ramos,Guzmán Guzmán

doi:10.3390/polym11101719

Fernández Fernández, Ramos Ramos + Show 1 more

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https://doi.org/10.3390/polym11101719

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Journal: Polymers	Publication Date: Oct 19, 2019
Citations: 8	License type: CC BY 4.0

Affiliation: University of the Basque Country

Abstract

The study of the non-isothermal crystallization behavior of polymers is of great importance due to the effect of degree of crystallinity and crystallization process on the polymer properties. The effect of aminopropylisobutyl polyhedral oligomeric silsesquioxane (APIBPOSS) and aminopropylisooctyl polyhedral oligomeric silsesquioxane (APIOPOSS) on poly(ε-caprolactone) (PCL) crystallization is studied by differential scanning calorimetry (DSC) under non-isothermal conditions and polarized optical microscopy (POM). The crystallization kinetics is analyzed using the Avrami and Mo models, and effective activation energies are evaluated by the Friedman isoconversional method. The results show that the compatibility between polyhedral oligomeric silsesquioxanes (POSS) and PCL and POSS loading affect the crystallization process. A higher crystallization temperature, a narrower size distribution of crystallite, and a faster crystallization rate are obtained in the presence of all the studied contents of APIBPOSS and at lower contents of APIOPOSS. At APIOPOSS contents higher than 2 wt %, the crystallization temperature is lowered, the size distribution of crystallite is broadened, and the crystallization process is retarded. The presence of POSS leads to an increase in the number of nucleation sites, and a reduction in the size of the crystallite and the overall degree of crystallinity, as a result of the confinement of PCL chains caused by POSS nanoparticles.

Highlights

Poly(ε-caprolactone) (PCL), a semi-crystalline aliphatic and biodegradable polyester, compatible with many types of polymers and having good biocompatibility, has been used in a wide range of applications including food packaging material, tissue engineering scaffolding, medical devices, and drug delivery systems [1,2]
PCL, PCL/APIBPOSS, and PCL/APIOPOSS composites containing 2, 5, and 10 wt % polyhedral oligomeric silsesquioxanes (POSS) were studied by differential scanning calorimetry (DSC)
The results showed that the crystallization process was affected by the POSS type and loading

Summary

Introduction

Poly(ε-caprolactone) (PCL), a semi-crystalline aliphatic and biodegradable polyester, compatible with many types of polymers and having good biocompatibility, has been used in a wide range of applications including food packaging material, tissue engineering scaffolding, medical devices, and drug delivery systems [1,2]. Some disadvantages such as slow crystallization rate, deficiencies in thermal stability, and poor mechanical properties have limited the applications of PCL. POSS molecules have been incorporated into organic polymers via copolymerization, grafting, or blending [8,9,10]. The incorporation of POSS molecules into some semi-crystalline polymers affects their crystallization behavior [11,12,13], and the physical and mechanical properties of a semi-crystalline polymer are strongly dependent on its crystallization and morphology

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