Structure and property relationship
Buncha Suksut; Pathamanat Poonkasem; Sirirat Prasittinawa; Patcharapon Somdee
Abstract
Composites of polypropylene (PP) and calcium lactate (CL) with a constant weight percentage of 60% and 40%, respectively, were compounded with 3, 5 and 7 phr of epoxidized soybean oil (ESO) plasticizer using an internal mixer. The testing samples were prepared using an injection molding technique. The ...
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Composites of polypropylene (PP) and calcium lactate (CL) with a constant weight percentage of 60% and 40%, respectively, were compounded with 3, 5 and 7 phr of epoxidized soybean oil (ESO) plasticizer using an internal mixer. The testing samples were prepared using an injection molding technique. The effects of the mold temperature and annealing treatment on the morphological and mechanical properties of PP-based composites using polarized optical microscopy (POM), differential scanning calorimetry (DSC), universal testing machines (UTM), and impact tester were performed. The results showed a remarkable increase in the elongation-at-break and impact strength, but a noticeable decrease in tensile strength and stiffness with increasing ESO contents. The experimental results also indicated that the higher mold temperature significantly improved the tensile strength and stiffness of samples due to an increase in spherulite size for neat PP, PP/CL composite and PP/CL composite with 3 phr of ESO. Additionally, annealing treatment enhanced the tensile and impact strengths of both neat PP and PP/CL composite, which was attributed to the increase in the crystal perfection and degree of crystallinity. These findings suggested that mechanical improvements using high mold temperature and annealing treatment were confined to the incorporation of an ESO plasticizer. The resulting performance of the plasticized PP composites after thermal treatment was described by two possibilities: the loss in the adhesion between the components and the migration of plasticizer.
Polymer physics
Buncha Suksut; Chonticha Seesong; Nutchalida Phueaksri; Chantarawan Chuephlob
Abstract
The effect of calcium lactate (CL) and epoxidized soil bean (ESO) on the crystallization kinetics of polypropylene (PP) was investigated by using polarized optical microscope (POM) and differential scanning calorimetry (DSC). The experiments were performed under both non-isothermal and isothermal conditions. ...
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The effect of calcium lactate (CL) and epoxidized soil bean (ESO) on the crystallization kinetics of polypropylene (PP) was investigated by using polarized optical microscope (POM) and differential scanning calorimetry (DSC). The experiments were performed under both non-isothermal and isothermal conditions. The development of spherulitic microstructure and crystallization kinetics were influenced by both CL and ESO. CL was an efficient nucleating agent for the crystallization of PP. The addition of CL facilitated faster spherulite growth and crystallization rate, while reduced the spherulite size. An opposite performance was discovered with the incorporation of ESO. Nucleation effect of CL on the PP crystallization was less effective with the presence of ESO. Compared with PP/CL, PP/CL/ESO provided a large spherulite size, slow spherulite growth, and a low crystallization rate. This is attributed to the ESO inhibited the nucleation site of CL. However, the degree of crystallinity and the Avrami exponents remained unchanged with the inclusion of both CL and ESO.
