In this study, palm oil-based polyurethane (PU)/montmorillonite (MMT) nanocomposite foams were produced via an in situ polymerization method. The palm oil-based polyol synthesized by transesterification reaction of palm oil and pentaerythritol was reacted with commercial polymeric diphenylmethane diisocyanate in the presence of water (blowing agent), N,N-dimethylcyclohexylamine (catalyst), polydimethylsiloxane (surfactant) and MMT to produce rigid PU nanocomposite foams. The obtained foams containing different MMT contents (1, 3, and 5 wt%) were characterized for their structure, morphology, density, hardness, compressive strength and thermal stability. X-ray diffraction patterns revealed that the nanocomposites formed were exfoliated. Scanning electron micrographs showed that the cells of the obtained PU foams were closed cells. The nanocomposite foams showed a higher number of cells with a smaller cell size as the amount of MMT increased. The density and the compressive strength of the foams increased with the increasing amount of MMT and were in the range of 38.5—46.6 kg/m3 and 116.7—171.6 kPa, respectively. Moreover, addition of MMT also improved the thermal stability of the foams.

This work sought to improve the toughness and thermal stability of poly(lactic acid) (PLA) by incorporating poly(butylene succinate) (PBS) and wood flour (WF). The PLA/PBS blends showed a PBS-dose-dependent increase in the impact strength, elongation at break, degree of crystallinity, and thermal stability compared to the PLA, but the tensile strength, Young's modulus, and flexural strength were all decreased with increasing PBS content. Based on the optimum impact strength and elongation at break, the 70/30 (w/w) PLA/ PBS blend was selected for preparing composites with five loadings of WF (5-30 phr). The impact strength, tensile strength, flexural strength, and thermal stability of the PLA/PBS/WF composites decreased with increasing WF content, and the degree of crystallinity was slightly increased compared to the 70/30 (w/w) PLA/PBS blend. Based on differential scanning calorimetry, the inclusion of PBS and WF into PLA did not significantly change the glass transition and melting temperatures of PLA in the PLA/PBS blends and PLA/ PBS/WF composites. From the observed cold crystallization temperature of PLA in the samples, it was evident that the degree of crystallinity of PLA in all the blends and composites was higher than that of PLA.

Postconsumer PET bottles including water and soft-drink bottles were depolymerized by glycolysis in excess glycols, such as ethylene glycol, propylene glycol, and diethylene glycol, in the presence of a zinc acetate catalyst. The obtained glycolyzed products were reacted with maleic anhydride and mixed with a styrene monomer to prepare unsaturated polyester (UPE) resins. These resins were cured using methyl ethyl ketone peroxide (MEKPO) as an initiator and cobalt octoate as an accelerator. The physical and mechanical properties of the cured samples were investigated. It was found that the type of glycol used in glycolysis had a significant effect on the characteristics of the uncured and cured UPE resins. Uncured EG-based UPE resin was a soft solid at room temperature, whereas uncured PG-and DEG-based resins were viscous liquids. In the case of the cured resins, the EG-based product exhibited characteristics of a hard and brittle plastic, while the PG-based product did not. The DEG-based product exhibited characteristics of hard and brittle plastic after strain-induced crystallization had occurred. In addition, it was also found that no separation of the type of bottles was needed before glycolysis, since UPE resins prepared from water bottles, soft-drink bottles, and a mixture of both bottles showed the same characteristics.

This study aimed to improve the brittleness and thermal stability of poly(lactic acid) (PLA) by inclusion of poly(butylene succinate) (PBS) and microcrystalline cellulose (MCC). Of the three PLA/PBS blends (10, 30 and 50 wt% PBS) evaluated, the 70/30 wt% blend exhibited the highest impact strength and elongation at break, but a lower thermal stability compared to that of the pure PLA. Scanning electron microscopy analysis confirmed the better compatibility of this 70/30 PLA/PBS blend. This blend was further filled with MCC. Based on thermogravimetric analysis, the thermal stability of the 70/30 PLA/PBS blend was improved by the addition of MCC [optimal at five parts by weight per hundred (phr)] and further still by the addition of the chain extender, Joncryl TM , at 0.5 phr. The 70/30/5/0.5 PLA/PBS/MCC/Joncryl TM composite exhibited the highest impact strength, while the elongation at break was acceptable.

Natural rubber was reinforced with a high loading of a cardanol-formaldehyde resin prepared from cashew nut shell liquid. Cardanol-formaldehyde resins, both resoles and novolaks, were synthesized from cardanol, which was extracted from cashew nut shells. This was done by the condensation polymerization of cardanol and formaldehyde in the presence of base and acid catalysts. The cardanol-formaldehyde resole with the highest yield (ca. 75%) was prepared with a formaldehyde/cardanol molar ratio of 2.0 at pH 8.0 and 908C for 8 h. The cardanol-formaldehyde novolak with the highest yield (ca. 80%) was prepared with a formaldehyde/cardanol molar ratio of 0.8 at pH 2.2 and 1008C for 7 h. Fourier transform infrared and 13 C-NMR were employed to characterize the chemical structures of the obtained cardanol-formaldehyde resins. The resins were compatible with natural rubber in various formulations. The cured behaviors of natural rubber blended with the cardanol-formaldehyde resole and novolak resins were investigated. The cured behaviors of cardanol-formaldehyde resole and cardanol-formaldehyde novolak samples were different, reflecting differences in their chemical reactivities. Furthermore, the incorporation of cardanol-formaldehyde resins into natural rubber provided significant improvements in mechanical properties such as the hardness, tensile strength, modulus at 100 and 300% elongation, and abrasion resistance. However, the elongation at break and compression set of the blends decreased as expected.