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In this study, the non-isothermal cold crystallization and isothermal melt crystallization of both linear and long-chain-branched (LCB) polylactide (PLA) were investigated using a differential scanning calorimeter (DSC). Talc was used as a nucleating agent to promote crystallization. The effects of chain branching on PLA’s cold crystallization kinetics at different heating rates and on PLA’s melt crystallization kinetics under different temperatures were studied by using Avrami analysis. The results showed that LCB-PLAs have faster cold and melt crystallization rates than those of linear PLA, since branched chains can play a role of nucleating site. Talc is a powerful nucleating agent, especially for linear PLA, either in cold crystallization or melt crystallization process. It was seen that addition of talc to PLA improves the crystallinity of PLA samples with more linear structure, more effectively because of its role of crystal nucleation. In PLA samples with more branched structure, talc has the least effect on crystallinity suggesting that the branched structure dominated crystallization already regardless of the presence of talc. Isothermal melt crystallization experimental results also showed that branched PLAs crystallized much faster than linear PLA and talc could increase the melt crystallization rate of linear PLA, but not that of PLA with a more branched structure.

Blends containing 75 wt. % of an amorphous polylactide (PLA) with two different molecular weights and 25 wt. % of a poly[(butylene adipate)-co-terephthalate] (PBAT) were prepared using either a Brabender batch mixer or a twin-screw extruder. These compounds were selected because blending PLA with PBAT can overcome various drawbacks of PLA such as its brittleness and processability limitations. In this study, we investigated the effects of varying the molecular weight of the PLA matrix and of two different mixing processes on the blend morphology and, further, on droplet coalescence during shearing. The rheological properties of these blends were investigated and the interfacial properties were analyzed using the Palierne emulsion model. Droplet coalescence was investigated by applying shear flows of 0.05 and 0.20 s−1 at a fixed strain of 60. Subsequently, small amplitude oscillatory shear tests were conducted to investigate changes in the viscoelastic properties. The morphology of the blends was also examined using scanning electron microscope (SEM) micrographs. It was observed that the PBAT droplets were much smaller when twin-screw extrusion was used for the blend preparation. Shearing at 0.05 s−1 induced significant droplet coalescence in all blends, but coalescence and changes in the viscoelastic properties were much more pronounced for the PLA-PBAT blend based on a lower molecular weight PLA. The viscoelastic responses were also somehow affected by the thermal degradation of the PLA matrix during the experiments.

This volume deals with the occurrence, production, and physical properties of metallic aluminum. The section on its occurrence includes an account of the aluminum minerals, including silicates, and contains a long section on bauxite and laterite, which are used in the technical production of the metal. The section on the production of the metal deals briefly with the older chemical methods and in detail with the electrolytic processes now in use, and with refining processes. The forms of commercial aluminum are described. The physical properties are classified under the headings atomic, crystallographic, mechanical, thermal, optical, magnetic and electrical, and in the descriptions a large amount of numerical data is collected. The volume provides a very exhaustive and authoritative account of aluminum metal both from the physical and chemical aspects, although the description of the purely chemical properties belongs to a later issue. The references are very complete and the literature, which is brought well up to date, is international.

Polylactide (PLA)/polyamide 11 (PA11) blends with 75/25 wt.% composition were prepared using an internal mixer. An epoxy-based chain extender, Joncryl ® ADR 4468, was used for reactive compatibilization of the blends. The effect of the mixing strategy of the chain extender with the blend components on its compatibilization effect and on the morphological, rheological, thermomechanical, and mechanical properties of the blends was determined. Due to more reactivity of the chain extender towards PLA compared to PA11, preparing the blends using the epoxy-modified PA11 resulted in enhanced compatibilization and a reduction of the number-average diameter of the dispersed droplets from 1.89 to 0.64 μm in the compatibilized blends. Larger complex viscosity and storage modulus were observed for blends prepared using the modified PA11 compared to blends from the modified PLA, consistent with the observed refinement of the morphology. Strain at break of the compatibilized blends increased to 150% compared to 6% for the neat PLA while maintaining the tensile strength and modulus at 62 MPa and 2 GPa (70 MPa and 2.4 GPa for PLA), respectively. The impact toughness increased from 24 J/m for neat PLA to around 40 J/m in compatibilized blends.