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Background we aimed to assess whether shortness of filum terminale (FT) can represent a specific feature of fibromyalgia. Therefore we investigated benefits coming from FT section with a mini-invasive technique in patients with fibromyalgia. Filum terminale disease (FD), described firstly in 1996, is consequence of an abnormal traction exerted on spinal cord since FT is shorter than usual. Fibromyalgia syndrome (FS) is featured by chronic widespread musculoskeletal pain associated with stiffness and extra-skeletal symptoms affecting many organs and systems. Filum terminale disease and fibromyalgia syndrome share common clinical features in at least one subset of patients. Methods we evaluated 42 patients firstly diagnosed for FS and then re-evaluated by nuclear magnetic resonance. 38 out of 42 had also FD and 20 of them underwent surgical treatment, i.e., FT section according to Royo-Salvador technique. Results after physical therapy, surgically treated patients showed significant improvement of symptoms in terms of reduction of pain and increment of quality of life, compared to group, which refused surgery and performed physical therapy only. Conclusion we suggest that FT shortness can be considered one of predisposing causes for developing FS and that FD surgical treatment in patients with FS can improve overall treatment outcome.

A new starch-based polymeric system, ZI1OU from Novamont, mainly composed of starch and polycaprolactone, was reprocessed several times in an extruder to investigate the recyclability of this biodegradable polymer. A previous investigation of the thermomechanical degradation in a mixer has been also done. The degradation is mostly due to the thermal stress but the presence of the mechanical stress strongly increases the degradation kinetic. During melt processing two concurrent processes take place: the first is the degradation, i.e. the breaking and shortening of polymeric chains, mostly occurring in the PCL phase; the second is the formation of some crosslinked structure in the starch phase. The rheological and mechanical properties, measured on samples subjected to repetitive extrusion operations carried out in a single screw extruder, clearly indicate that, in the adopted processing conditions, no significant modifications are observed. Only after five extrusions some decrease of these properties was measured.

The compatibilization of blends of polyamide-6 (PA6) with linear low density polyethylene (LLDPE) and of poly(ethylene terephthalate) (PET) with high density polyethylene (HDPE), by functionalization of the polyethylenes with oxazoline groups was investigated. Chemical modification of LLDPE and HDPE was carried out by melt free radical grafting with ricinoloxazoline maleinate. Blends preparation was made either with a two-steps procedure comprising functionalization and blending, and in a single step in which the chemical modification of polyethylene with the oxazoline monomer was realized in situ, during blending. The characterization of the products was carried out by FTIR spectroscopy and scanning electron microscopy (SEM). The rheological and mechanical properties of the blends were also investigated. The results show that functionalization of the polyethylenes can be achieved by melt blending with ricinoloxazoline maleinate even in the absence of free radical initiators. The compatibilization of the blends enhances the dispersion of the minor phase significantly, increases the melt viscosity, and improves the mechanical properties. The one-step preparation of the compatibilized blends was also found to be effective, and is thought to be even more promising in view of commercial application.

The rheology, morphology, and mechanical properties of blends of high-density polyethylene (HDPE) with a semiflexible liquid crystalline copolyester (SBH) were studied in order to assess the compatibilizing ability of added PE-g-SBH copolymers, and its dependence on the molar mass of the PE matrix, and on the technique used for blend preparation. The PE-g-SBH copolymers were synthesized as described in previous articles, either by the polycondensation of the SBH monomers in the presence of a functionalized PE sample containing free carboxyl groups, or by reactive blending of the latter polymer with preformed SBH. Two samples of HDPE having different molar masses, and two samples of SBH with different melt viscosity and different microstructure, were used for preparing the blends. The two components and the compatibilizer were either blended in a single batch or used to prepare binary master blends to which the third component was added at a later stage. The results indicate that the PE-g-SBH copolymers do, in fact, compatibilize the PE–SBH blends and that the effect is more pronounced with the lower molar mass PE matrix and with the SBH sample having lower viscosity. The experiments carried out on blends prepared with different techniques show that the compatibilizing ability of the graft copolymer is improved if the latter is first blended with either of the two main components. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 603–613, 1999

The mechanical properties of blends with liquid crystalline polymers are in general poor and lower than those expected on the basis of additivity rule because of the strong incompatibility between the flexible and rigid components. Compatibilization is then necessary to enhance the adhesion between the two phases and then to improve the final properties of these blends. The addition of maleic anhydride functionalized polymers could give rise to some compatibilization because of possible reactions between the maleic anhydride group and the end groups of the liquid crystalline polymers. These reactions do not seem to occur in blends of polyethylene and a semirigid liquid crystalline polymer. The small increase of viscosity and of some mechanical properties can be ascribed to the occurrence of polar interactions, such as hydrogen bonding between the components.

Reactive blends (50/50 w/w) of a low molar mass polyethylene containing free carboxylic groups (PEox) and a semiflexible liquid crystalline polyester (SBH 1 : 1 : 2, by Eniricerche) have been prepared at 240 degrees C in a Brabender mixer, in the presence of Ti(OBu)(4) catalyst, for different mixing times (15, 60, and 120 min). In order to prove the formation of a PE-g-SBH copolymer, the blends have been fractionated by successive extractions with boiling toluene and xylene. The soluble fractions and the residues have been analyzed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG and DTG), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). All analytical procedures concordantly show that PE-g-SBH copolymers with different compositions, arising from differences of either the number of PEox carboxylic groups entering the transesterification or the length of grafted SBH branches, are formed as a result of blending. Depending on the relative content of PE and SBH segments, the copolymers dissolve in the solvents, together with any unreacted PEox, or remain in the residues, together with neat SBH. Qualitative IR analyses and quantitative TG measurements have shown that the amount of copolymers increases strongly with the mixing time. Preliminary SEM observations indicate that the unfractionated products of the reactive blending carried out with long (120 min) mixing times lead to improved interfacial adhesion and phase dispersion when added to PE/SBH blends.