Additives effects on the shrinkage behavior of PVC sheets

The Use of New Waste-Based Plasticizer Made from Modified Used Palm Oil for Non-Glutinous Thermoplastic Starch Foam

A novel waste-based plasticizer derived from modified used palm oil (mUPO) was successfully developed and has been used as a new plasticizer to non-glutinous thermoplastic starch foam to improve their properties. The molecular weight and hydroxyl number of the mUPO was 3150 g/mol and 192.19 mgOH/g, respectively. The effects of mUPO content ranging from 0 to 9 phr were investigated. The results revealed that the optimal mUPO content as an additive was 6 wt%. The addition of mUPO had a direct effect on the mechanical properties and thermal properties. The impact strength increased from 1.30 to 4.55 J/m, while the glass transition temperature (T_g) decreased from 70.83 to 66.50 °C by increasing mUPO from 0 phr to 6 phr in the thermoplastic starch foam. The mUPO, on the other hand, has also the potential to reduce shrinkage from 33.91 to 21.77% and moisture absorption from 5.93 to 1.73% by increasing the content from 0 phr to 6 phr in starch foam. Furthermore, the mUPO helps the forming of the foam structure as measured by SEM, and the mUPO utilization of waste-based material could be a promising green alternative plasticizer for starch components, especially starch foam applications.

Development of PLA/EVA Reactive Blends for Heat-Shrinkable Film

Heat-shrinkable films have widely been used for various applications such as shrinkable labels and cap seals. These plastics have generally a short life. The biodegradable polymers can thus be an ideal candidate for such applications. This work aimed to study the stretching and shrinking ratio of poly(lactic acid)/ethylene vinyl acetate through reactive blends system for heat-shrinkable films application. The reactive agents, Joncryl^® and Perkadox were used as in situ compatibilizers. PLA/EVA with 100/0, 97/3, 95/5, 93/7, and 90/10 ratios were prepared in the twin screw extruder. Neat PLA and PLA/EVA films were fabricated by blown film extrusion. The results revealed that the elongation at break of PLA in the TD direction was improved when adding EVA. PLA and EVA film with 0.1 phr of Perkadox was found to be sufficient as evident by FESEM micrograph and DMTA results. The films were stretched and shrunk at a temperature of 70 °C. The percentage of shrinkage of the stretched PLA/EVA reactive blend films, two and three times were, 100%, approximately. On the other hand, the four-times stretched films shrunk less than 100% because of the excessive stretching, which resulted in film breakage and defect.