Effect of injection parameters on the thermal, mechanical and thermomechanical properties of polycaprolactone (PCL). (December 2021)

• Record Type: Journal Article
• Authors: Luna, Carlos Bruno Barreto; Siqueira, Danilo Diniz; Ferreira, Eduardo da Silva Barbosa; Araújo, Edcleide Maria; Wellen, Renate Maria Ramos
• Is Part Of: Journal of elastomers and plastics. Volume 53:Number 8(2021)
• Page Start: 1045
• Page End: 1062
• Publication Date: 2021-12
• Subjects: Biopolymer -- polycaprolactone (PCL) -- processing conditions -- injection -- properties; Plastics -- Periodicals; Elastomers -- Periodicals; 668.405
• DOI: 10.1177/00952443211015345
• Languages: English
• ISSNs: 0095-2443

Abstract

In this work, an experimental design was applied in the injection molding process of polycaprolactone (PCL), aiming to evaluate the mechanical properties (impact strength, tensile strength and Shore D Hardness), thermal (differential scanning calorimetry (DSC)) and thermomechanical (heat deflection temperature (HDT)), in PCL injected specimens. A type 2 n planning was applied, with n = 3 and central point, having the input factors: processing temperature profile, mold temperature and injection flow. The results showed that the DSC curves presented a complex mechanism during crystallization, suggesting that depending on the processing conditions a high degree of crystallinity can be obtained. When using a higher processing temperature and a higher injection flow, there is an increase in the mass of the PCL parts. The impact strength is more expressive when a higher injection flow and a lower processing temperature are applied, reaching values around 260 J/m. The mold temperature impairs the elongation at the break of the PCL, while the elastic modulus was governed by the degree of crystallinity. A deleterious effect on HDT was observed with increased injection flow, suggesting that this parameter negatively affects thermomechanical resistance. The use of experimental design in the processing of PCL is important, since it is possible to optimize properties with the ideal conditions of injection molding.