THE OBJECTIVES OF THIS STUDY WERE TO EVALUATE THE EFFECT OF KNIFE WEAR ON THE GLUABILITY OF PLANED SURFACES OF RADIATA PINE. A CONVENTIONAL PROCESS WAS USED TO PLANE SAMPLES TO FOUR LENGTHS: 200; 10,000; 20,000; AND 30,000 M. CUTTING-EDGE RECESSION WAS MEASURED ON THE CLEARANCE SURFACE OF THE PLANING KNIFE FOR EACH LENGTH. THE GLUING PROPERTIES OF THE PLANED SURFACES WERE DETERMINED FOR EACH OF THE FOUR LEVELS OF KNIFE WEAR USING POLYVINYL ACETATE AND EMULSION POLYMER ISOCYANATE ADHESIVES. THE RESULTS SHOWED THAT THE GREATEST AMOUNT OF CUTTING-EDGE RECESSION ON THE CLEARANCE SURFACE WAS 65 MM AFTER 30,000 M OF PLANING. THE TENSILE SHEAR STRENGTH (TSS) OF THE LAP-JOINT GLUE LINE DECREASED WITH KNIFE WEAR FROM INCREASED PLANING. HOWEVER, TSS WAS GENERALLY GREATER THAN THE MINIMUM PRESCRIBED BY THE BS EN 204 STANDARD. THE EFFECT OF KNIFE WEAR ON TSS WAS MORE SIGNIFICANT AFTER ACCELERATED AGING OF THE GLUED SAMPLES.

THE MORPHOLOGY AND THERMO-MECHANICAL PROPERTIES OF RECYCLED POLYSTYRENE-BASED MATERIALS (RPS) REINFORCED WITH 5 AND 15% LIGNIN FROM KRAFT PULPING OF EUCALYPTUS NITENS WERE STUDIED. THE LIGNIN WAS MODIFIED THROUGH TWO ESTERIFICATION PROCESSES USING EITHER ACETIC OR MALEIC ANHYDRIDE, AND CHANGES IN THE STRUCTURE OF THE ESTERIFIED LIGNIN FUNCTIONAL GROUPS WERE ANALYZED BY FOURIER TRANSFORM INFRARED SPECTROSCOPY. THE LIGNIN WAS THEN INCORPORATED INTO RPS BY MELT MIXING. TORQUE VARIATION IN THE PROCESS WAS EVALUATED, AND THE VALUES WERE COMPARED TO THOSE OF NEAT RPS AND VIRGIN PS. THE RESULTS SHOW A PLASTICIZING EFFECT OF LIGNIN WITH A REDUCTION IN THE TORQUE VALUES. THE MORPHOLOGY, STUDIED THROUGH SCANNING ELECTRON MICROSCOPY, SHOWS A PARTICLE SIZE REDUCTION OF ACETYLATED AND MALEATED LIGNIN AND A MORE HOMOGENEOUS DISPERSION AT 5%. THE THERMAL BEHAVIOR OF THE COMPOSITES, STUDIED THROUGH DIFFERENTIAL SCANNING CALORIMETRY, DOES NOT SHOW SIGNIFICANT CHANGES IN THE GLASS-TRANSITION TEMPERATURE OF RPS WITH THE PRESENCE OF LIGNIN. THE DYNAMIC MECHANICAL ANALYSIS SHOWS AN INCREASING STORAGE MODULUS WITH INCREASING LIGNIN CONTENT. THERMAL STABILITY, STUDIED THROUGH THERMOGRAVIMETRIC ANALYSIS, IMPROVED FOR COMPOSITES CONTAINING 5% ESTERIFIED LIGNIN. THE FLEXURAL MODULUS ALSO INCREASED WITH LIGNIN ADDITION. THESE RESULTS SUGGEST THAT THE THERMAL AND MECHANICAL PROPERTIES OF POST-CONSUMER RECYCLED POLYSTYRENE CAN BE SIGNIFICANTLY IMPROVED WITH ONLY 5% ESTERIFIED LIGNIN.

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

IN THIS WORK, THE CHANGES CAUSED BY A CHEMICAL MODIFICATION OF THE PROPERTIES AND CHEMICAL STRUCTURES OF LIGNIN ARE STUDIED. LIGNIN FROM A MIXTURE OF EUCALYPTUS GLOBULUS AND EUCALYPTUS NITENS OBTAINED THROUGH THE KRAFT PULPING PROCESS WAS USED. THE LIGNIN WAS ISOLATED BY ACID PRECIPITATION AND MODIFIED BY A REACTION WITH MALEIC ANHYDRIDE. MALEATED LIGNIN (ML) WAS INCORPORATED TO RECYCLED POLYSTYRENE (RPS) AT 2, 5, AND 10 WT-% BY A MELT-BLENDING PROCESS. FOURIER TRANSFORMED INFRARED SPECTROSCOPY (FT-IR) WAS USED TO DETERMINE THE ML STRUCTURE, AND THE MORPHOLOGY OF RPS/ ML COMPOSITES WAS STUDIED BY SCANNING ELECTRON MICROSCOPY (SEM). DIFFERENTIAL SCANNING CALORIMETRY (DSC) AND THERMOGRAVIMETRIC ANALYSIS (TGA) WERE USED TO STUDY THE GLASS-TRANSITION TEMPERATURE (TG) AND THE THERMAL STABILITY OF RPS AND RPS/ ML COMPOSITES AND WERE COMPARED WITH VIRGIN PS. THE TG VALUES OF RPS AND THEIR COMPOSITES WERE HIGHER THAN THOSE OF THE VIRGIN PS. TGA REVEALED THAT THE THERMAL STABILITY OF RPS WITH 2 AND 5% OF ML WAS SLIGHTLY GREATER THAN THAT OF THE VIRGIN PS. THESE RESULTS SUGGEST THAT POSTCONSUMER PS CAN BE USED TO OBTAIN COMPOSITE MATERIALS WITH GOOD THERMAL PROPERTIES.

THE DEVELOPMENT OF NANOSTRUCTRUCTURED POLYMETHILMETHACRYLATE (PMMA) SURFACES WAS STUDIED BY THE INCORPORATION OF SILICA, ALUMINA AND SILICA-ALUMINA, THE FORMER OBTAINED BY SOL-GEL PROCEDURE. THE MATERIALS WERE OBTAINED IN A POLYMER SOLUTION (ACETONE, ISOPROPANOL) AND CONTAINS VARIABLE AMOUNTS OF THE INORGANIC COMPONENT (10 AND 20 % IN THE MASS). THE SEM STUDIES SHOW THE MODIFICATION OF THE POLYMER STRUCTURE BY THE ADDITION OF THE SILICON OXIDE AND ALUMINUM OXIDE; THOUGH NOT ALL THE SAMPLES SHOW A HIGH DISPERSION OF THE INORGANIC COMPONENT. THE FT-IR SPECTRUM SHOWED A REDUCTION IN THE INTENSITY OF THE CARBONYL SIGNAL ASSOCIATED TO THE POLYMER, DUE TO THE INCORPORATION OF THE FILLER AND THE PRESENCE OF BANDS ATTRIBUTED TO THE INORGANIC COMPONENTS INCORPORATED. THROUGH TGA AND DSC STUDIES THE MODIFICATION OF THE THERMAL STABILITY OF THE POLYMER WAS PROVED, DEPENDING ON THE INORGANIC COMPONENT USED AND ITS COMPOSITION.

POLYPROPYLENE COMPOSITES WITH 5 TO 10% OF SIO2, AL2O3 Y TIO2 NANOPARTICLES WERE SYNTHESIZED. THE OXIDES WERE OBTAINED USING THE SOL-GEL TECHNIQUE AND WERE ADDED TO THE MOLTEN POLYPROPYLENE. THE MORPHOLOGY OF NANOPARTICLES WAS OBSERVED BY SCANNING ELECTRON MICROSCOPY AND SHOWED THAT THE INCORPORATION OF TIO2 AND SIO2 GELS PRODUCES HIGH DISPERSION OF THE FILLER, WHILE THE USE OF AL2O3 RESULTS IN AGGREGATES OF THESE NANOPARTICLES IN THE POLYMER MATRIX. THE X-RAY DIFFRACTOGRAM OF THE COMPOSITES REVEALED A DISPLACEMENT OF CHARACTERISTICS LINES OF POLYPROPYLENE AND AN INCREMENT OF THE INTERPLANAR SPACES, INDICATING SOME INTERACTION BETWEEN THE COMPONENTS AND THE PREDOMINANCE INTERCALATION OF OXIDES. THROUGH FT-IR IT WAS NOTICED THE PRESENCE OF FUNCTIONAL GROUPS ATTRIBUTABLE TO THE FILLER NANOPARTICLES. THE CRYSTALLIZATION, THE FUSION BEHAVIOUR AND THE THERMAL STABILITY OF THE COMPOSITES WAS STUDIED USING DIFFERENTIAL SCANNING CALORIMETRY AND THERMOGRAVIMETRIC ANALYSIS IT WAS FOUND A REDUCTION IN THE CRYSTALLIZATION TEMPERATURE AND INCREMENT IN THE THERMAL STABILITY OF THE POLYPROPYLENE MATRIX DUE TO THE ACTION OF THE SILICA, ALUMINA AN TITANIA NANOPARTICLES.

POLYSTYRENE (PS) FROM PACKING MATERIALS AND PLASTIC CUPS WAS REINFORCED WITH 30 AND 50% WOOD FLOUR THROUGH A BLENDING PROCESS WITH AND WITHOUT A COMMERCIAL COMPATIBILIZING AGENT. THE PROCESSABILITY OF THE PURE RECYCLED POLYSTYRENE (RPS) AND WOOD?RPS COMPOSITES WAS STUDIED IN TERMS OF THE TORQUE OF THE MIXING PROCESS; THIS WAS THEN COMPARED WITH THAT OF A COMMERCIAL VIRGIN MULTIPURPOSE PS. THE PHYSICAL AND MECHANICAL PROPERTIES WERE COMPARED WITH THOSE OF THE VIRGIN PS REINFORCED WITH 30 AND 50% WOOD FLOUR. THE RESULTS SHOW THAT THE MECHANICAL PROPERTIES OF THE PURE AND REINFORCED RPS DID NOT DECREASE WITH RESPECT TO THE VIRGIN PS, AND IN TERMS OF THE IMPACT STRENGTH, THE RPS WAS SUPERIOR TO THE VIRGIN PLASTIC. THE MECHANICAL PROPERTIES WERE NOT AFFECTED BY THE COMMERCIAL COMPATIBILIZING AGENT, BUT THE TORQUE OF THE BLENDS WAS SIGNIFICANTLY LOWER WITH THE COMPATIBILIZER. DIFFERENTIAL SCANNING CALORIMETRY (DSC) AND DYNAMIC MECHANICAL ANALYSIS WERE USED TO STUDY THE GLASS-TRANSITION TEMPERATURE (TG) OF BOTH THE PURE VIRGIN PS AND PURE RPS AND THE WOOD FLOUR?PS COMPOSITES. THE TG VALUES OF THE RPS AND WOOD?RPS COMPOSITES WERE HIGHER THAN THOSE OF THE VIRGIN PS AND WOOD?VIRGIN PS COMPOSITES. THE USE OF RPS INCREASED THE STIFFNESS AND FLEXURAL MODULUS OF THE COMPOSITES. THERMOGRAVIMETRIC ANALYSIS REVEALED THAT THE THERMAL STABILITY OF RPS AND ITS COMPOSITES WAS SLIGHTLY GREATER THAN THAT OF THE VIRGIN PS AND ITS COMPOSITES.