Synthesis of Complex Oligoesters Based on Adipic Acid, Ethanediol and Butanediol-1,4 with Specified Characteristics

Aliphatic linear oligoesters with terminal hydroxyl groups and given molecular weight characteristics, hydroxyl and acid numbers were synthesized by esterification of adipic acid, ethylene glycol and butanediol-1,4. It was found that the main properties of complex oligoesters largely depend on the ratio of the starting reagents. The kinetic regularities of the process of esterification of adipic acid, ethylene glycol and butanediol-1,4 have been studied and determined. It was found that the duration of the vacuum stage of esterification in the presence of organomodified montmorillonite is noticeably shorter than when using a commercial catalyst.

Study of the Effect of Organoclay on the Structure of Cable PVC Compound

The effect of the organoclay content in polyvinyl chloride plasticate on the features of the supramolecular structure and properties of the layered silicate nanocomposite was studied. X-ray diffraction studies showed that with an increase in the number of layered silicate nanofiller, the nanocomposite structure goes from intercalated to exfoliate. Using a combination of scanning and atomic force electron microscopy methods, it has been shown that when organomodified montmorillonite is introduced into polyvinyl chloride plastic compound, montmorillonite nanoparticles act as crystallization nuclei and along with the preservation of “old” supramolecular structures in the melt, “new” supramolecular formations appear. When studying the dependence of tensile strength of nanocomposite polyvinyl chloride on the content of nanofiller, it was found that the maximum strength of the nanocomposite is achieved at a 5-7 % organoclay concentration.

Development of Bionanocomposites Based on Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)/PolylActide Blends Reinforced with Cloisite 30B

In the present study, poly(3-hydroxybuturate-co-3-hydroxyvalerate) (PHBV) and plasticized polylactide acid (PLA) blends were processed by melt extrusion with different weight ratio (up to 20 wt.% of PHBV). Bionanocomposites were obtained through the incorporation of an organomodified montmorillonite (C30B) at 3 wt.%. The main features of the processing and physico-chemical characterization of films and injected samples were assessed and the influence of the components on the chemical, thermal and mechanical properties of the bionanocomposites was investigated. The results indicated that plasticized PLA/PHBV/C30B bionanocomposites present optimal mechanical properties for sanitary applications. Moreover, plasticized PLA/PHBV could lead to finely tuned biomaterials able to form electrospun nanofibers.

Effect of Nano-Clay and Surfactant on the Biodegradation of Poly(Lactic Acid) Films

This study examined the effect of nanoclays and surfactant on the hydrolytic degradation and biodegradation of poly(lactic acid) (PLA) and PLA nanocomposites. Organomodified montmorillonite (OMMT), unmodified montmorillonite (MMT) and an organomodifier (surfactant) for MMT (QAC) were extruded with PLA to produce PLA nanocomposites. The films were produced with the same initial molecular weight, thickness and crystallinity since these properties have a significant effect on the biodegradation process. The biodegradation experiments were carried out in an in-house built direct measurement respirometric system and were evaluated in inoculated vermiculite and vermiculite media for extended periods of time. Hydrolysis experiments were also conducted separately to decouple the abiotic/hydrolysis phase. The results showed no significant variation in the mineralization of PLA nanocomposites as compared to pristine PLA. The addition of nanoclays did not enhance the biodegradability of PLA when the initial parameters were strictly controlled. The hydrolysis test indicated that the nanoclays and surfactant did not aid in the degradation of PLA.

OBTAINING TECHNOLOGY FOR NANOCOMPOSITES BASED ON POLYAMIDE-6 AND ORGANOMODIFIED MONTMORILLONITE

The obtaining technology of nanocomposites based on polyamide-6 and organomodified montmorillonite is developed. The technological parameters of extrusion and injection molding, and their influence on the formation of nanoscale inorganic phase of the polyamide are investigated. Morphology and thermal behavior of polyamide-6, composites based on polyamide-6 and modified montmorillonite are studied by WAXS, XRD, DTA and DSC data. Morphology and thermal behavior of polyamide-6 and composites based on polyamide-6 and modified montmorillonite are shown to be in a strong juxtaposition. New γ-phase formation is revealed in composite polyamide-6 – 1–2 % of modified montmorillonite in contrast with polyamide-6 and mechanical mixtures of polyamide-6 and montmorillonite. Optimal concentrations of modified montmorillonite in the composites stated as 1 – 2 % are shown to correspond with composites improved properties as compared to initial polyamide-6. It is explained by increasing crystallinity degree, which resulted from acting of modified montmorillonite particles as nucleation heterogenetic agents.

The Barrier Properties of Carbon-Chain and Heterochain Polymers and Polymer Composite Materials

A comparative assessment of the gas barrier properties of polymeric materials of different chemical structure and of composites with organomodified montmorillonite based on polyamide-6 is carried out, with the aim of using them as a barrier layer for polymer hot water pipes.