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Natural oils from watermelon, cherry, black currant, grape and pomegranate fruit seeds were applied in the synthesis of biopolyols using the transesterification reaction. In this manuscript, the preparation possibility of open-cell foams from a polyurethane system in which petrochemical polyol was fully replaced with biopolyols is analyzed. Firstly, polyurethane foam systems were developed on a laboratory scale, and they were next tested under industrial conditions. It was shown that the foaming method has a significant impact on the foaming process and the cell structure of obtained foams as well as their thermal insulation properties. Based on the conducted research, it was found that the method of processing the polyurethane system has a significant impact on the properties of open-cell spray foams. Foams produced under industrial conditions have a much higher cell density, which has a positive effect on their selected physical–mechanical properties compared to foams produced on a laboratory scale. The open-cell biofoams obtained using a high-pressure machine had apparent densities 12–17 kg/m3, thermal conductivity coefficients 35–37 mW/m·K, closed-cell contents < 10% and were dimensionally stable at low and high temperatures. [ABSTRACT FROM AUTHOR]

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Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rigid polyurethane–polyisocyanurate foams were synthesized using newly obtained compounds: tris(4-hydroxybutyl) 2-hydroxypropane-1,2,3-tricarboxylate and tris(3-hydroxybutyl) 2-hydroxypropane-1,2,3-tricarboxylate. The industrial Rokopol-551 used as polyol was gradually substituted for the new compounds in the polyol premix in new foams. The authors examined the effect of those compounds on the foams' combustibility, thermal properties and changes in linear dimensions, volume and weight after 48 h of thermostating in ventilated drier at 120℃. Changes in linear dimensions, volume, or weight did not occur at all or were not substantial. A slight decrease in foams' heat conductivity can be noticed when using new polyols in comparison to the reference foam (P0). The addition of polyols to the foams affects the foams' burning process. The values of those temperatures were decreasing along with the increasing amount of the used polyols in the foams, from 661℃ (P0 reference foam, not containing new polyol), to 612℃ (P6.5 foam, containing 0.5 equivalent of tris(4-hydroxybutyl) 2-hydroxypropane-1,2,3-tricarboxylate] and to 643℃ [P11.5 foam, containing 0.5 equivalent of tris(3-hydroxybutyl) 2-hydroxypropane-1,2,3-tricarboxylate). [ABSTRACT FROM AUTHOR]

ABSTRACT A rapeseed oil-based polyol (ROPO) was synthesized using chemical modification of the rapeseed oil (RO) by epoxidation reaction followed by oxirane ring-opening with diethylene glycol. The ROPO was used in the formulation of low-density green polyurethane (PU) foams. The use of glycerol as hydroxyl component, water as a reactive blowing agent and micro/nanocellulose (MNC) as a reinforcement increases the content of natural components in the formulations with important effects on the final foam properties. The ROPO and their intermediate products are characterized by analytical techniques and FTIR spectroscopy, while the final PU foams are characterized by morphological and mechanical analysis. The results show that the addition of glycerol increases the modulus and yield stress. The incorporation of MNC in small amounts is enough to increase the modulus at low temperatures. Both modifiers cause an increase in water absorption and the fragility of the cell walls, reflected in the micrographs of the foams. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41602. [ABSTRACT FROM AUTHOR]

Rigid polyurethane foams (RPURF) containing a bio-polyol from rapeseed oil and different phosphorus-based flame retardants were obtained. Triethyl phosphate (TEP), dimethyl propane phosphonate (DMPP) and cyclic phosphonates Addforce CT 901 (20 parts per hundred polyol by weight) were used in the synthesis of RPURF. The influence of used flame retardants on foaming process, cell structure, and physical–mechanical properties as well as flammability of RPURF were examined. The addition of flame retardants influenced the parameters of the cellular structure and decreased compressive strength. All obtained foam materials had a low thermal conductivity coefficient, which allows them to be used as thermal insulation. The research results of bio-based RPURF were compared with foams obtained without bio-polyol. All modified materials had an oxygen index above 21 vol%; therefore, they can be classified as self-extinguishing materials. The analysis of parameters obtained after the cone calorimeter test showed that the modified RPURF have a lower tendency to fire development compared to the reference foams, which was particularly noticeable for the materials with the addition of DMPP. [ABSTRACT FROM AUTHOR]

Aim of the Study: Evaluation of the influence of the introduced structure modification in porous ceramic grafts on TiO2 base on overgrowing with bone tissue, in examinations with use of scanning microscopy and X-rays was the subject of the examinations., Material and Method: New ceramic materials based on TiO2 with high values of mechanical resistance, large sintering degree and biocompatibility in in vitro conditions were prepared. Those properties cause that they are worth interest as potential osteosubstitutive materials. Two kinds of grafts were created from ceramics based on TiO2: with compact and porous structure. The introduced structure modification - macroporosity - had the purpose to give osteoconductive properties to the grafts, to evoke processes favorable for bone tissue forming. In examinations of the local reaction of bone tissue after implantation of the formed porous grafts, degree of their osteointegration, the essential issue is the evaluation of the settling of the inner spaces with supporting tissues. Samples of the tested compact and porous materials in the form of cylinders were implanted in femoral bones of rabbits for a period till 6 months. The surfaces of grafts and the degree of their settling with supporting tissues were evaluated in cross-sections of the implants with light and scanning microscopic methods and they were confirmed in X-ray tests., Results: Analysis of the obtained data showed that, the surface of solid ceramic on TiO2 base was covered mainly with increasing with a time of observation quantities of extracellular substance and lamellas of bone. The macrporous structure of porous ceramic on TiO2 base enabled settling of the inner spaces of graft with supporting tissue cells, partly in the 1st month, more intensively in the 3rd and it was not completed in the 6th month after implantation., Conclusions: Porous grafts in the form of ceramic foam on TiO2 base showed osteoconductive properties, though process of colonization after 6th month observation was not completed and the condition of the cells inside of the implant was reduced.