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There is a continuing demand for bio-sustainable and readily recyclable polymers for hot food packaging and hot beverage containers. An important candidate for these applications is poly(lactic acid), PLA, which possesses insufficient heat deflection temperature (HDT) performance, short of being fully crystallized. In order to address this issue, correlations were established for the observed enhancement in HDT with PLA resin after annealing with both thermal properties and the crystallinity of PLA (Ingeo™ 4032D) and extrusion melt blends thereof. The kinetic parameters of crystallization (reaction order, n and rate constant, k (s)) were obtained after fitting the Avrami equation. The reaction order for all of the systems had an n of approximately 3. Models derived from the Avrami equation with n ~ 3 are consistent with systems that undergo heterogeneous nucleation and subsequent spherulitic crystal growth. The addition of paper and talc did not change the model but did change the rate of crystallization. An increased quantity of cellulosic filler led to an increased rate of crystallization. The smaller particle sized fillers offered the greatest improvement in the rate of crystallization. However, the smaller-sized inorganic fillers did not appear to further improve HDT above that of the annealed blends of PLA/paper. The melting temperature for the PLA and all of the blends thereof formed containing paper from different sources of talc had identical melting temperatures ( T ). The variations in the HDTs of the composites were not found to be mirrored in the T . Annealing typically raised the crystallinity from approximately 10-15 to 30-40%. In situ determinations of enhanced moduli via annealing were performed using solid torsion bar dynamic mechanical spectroscopy, the results of which support the findings obtained via DSC. The annealed PLA/paper blends were found to be superior overall to the PLA/talc blends and are, importantly, sustainable. [ABSTRACT FROM AUTHOR]

We investigated the filling process of cellulose-based paper with natural clay nanotubes and their mixtures with hydroxypropyl cellulose (HPC) that is commonly used as glue and consolidant for degraded paper. A comprehensive characterization of the materials was carried out through morphology, wettability, thermal degradation, and tensile properties. The treatment with halloysite nanotubes generated a decrease of the paper mechanical performance and did not alter the thermal properties. The co-presence of HPC and nanoparticles generated a more uniform nanotubes distribution in the paper fibrous structure and a significant enhancement of both the mechanical properties and the surface hydrophobicity with respect to the HPC treatment. This work proposes the use of halloysite/HPC mixture in a new protocol for paper consolidation and represents a starting point to develop, with a biocompatible approach, smart composite material in which the nanotube cavity is filled with active species for paper protection or active response to external stimuli. [ABSTRACT FROM AUTHOR]

In this study, some results of previous studies concerning papyrus and paper, with special regard of artistic and archaeological materials, are reported and discussed. A historical introduction of such cellulose-based materials and of their use from the antiquity is presented first. The diagnostics and conservation aspects are discussed. The role of thermal analysis for a precise characterisation of these materials is illustrated. Complementary methods of investigation, such as optical microscopy, electron microscopy, X-ray diffraction and various types of spectroscopy are also considered. In addition, alteration or restoration processes may be usefully monitored by means of reflectance spectrophotometric measurements. [ABSTRACT FROM AUTHOR]

The paper deals with the study of thermal degradation of some new and old paper supports. The experimental data allows the prediction of the dependence between the half time and the temperature at which the paper support must to be kept. [ABSTRACT FROM AUTHOR]