Sustainable Reactive Polyurethane Hot Melt Adhesives Based on Vegetable Polyols for Footwear Industry

The aim of this work is to develop sustainable reactive polyurethane hot melt adhesives (HMPUR) for footwear applications based on biobased polyols as renewable resources, where ma-croglycol mixtures of polyadipate of 1,4-butanediol, polypropylene and different biobased polyols were employed and further reacted with 4-4′-diphenylmethane diisocyanate. The different reactive polyurethane hot melt adhesives obtained were characterized with different experimental techniques, such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), softening temperature and melting viscosity. Finally, their adhesion properties were measured from T-peel tests on leather/HMPUR adhesives/SBR rubber joints in order to establish the viability of the used biobased polyols and the amount of these polyols that could be added to reactive polyurethane hot melt adhesives satisfactorily to meet the quality requirements of footwear joints. All biobased polyols and percentages added to the polyurethane adhesive formulations successfully met the quality requirements of footwear, being comparable to traditional adhesives currently used in footwear joints in terms of final strength. Therefore, these new sustainable polyurethane adhesives can be considered as suitable and sustainable alternatives to the adhesives commonly used in footwear joints.

Change in Properties of Bitumen Used for Road Construction in Bitumineral Mixtures

Premature destruction of asphalt concrete can be caused by the aging of bitumen, which is associated with a change in the physical and chemical properties of bitumen. The article shows that in most cases, the improvement of the characteristics of asphalt concrete is achieved through the introduction of additives that affect the basic properties of the bituminous binder, such as penetration, softening temperature, viscosity. The influence of the chemical composition of the mineral filler on the rate of bitumen aging has been experimentally proved. The obtained research data show that the increase in the rate of aging of bitumen is influenced by the compounds of silicon and aluminum. On the other hand, metals such as iron and titanium contribute to the preservation of the initial plasticity of bitumen, and the accumulation of asphaltenes in the structure of the bitumen-mineral mixture slows down.

INVESTIGATION OF THE PROCESS OF MODIFICATION OF PETROLEUM ROAD BITUMEN BY MALEIC ANHYDRIDE

The possibility of modification of oxidized petroleum bitumen 70/100 produced by JSC "Ukrtatnafta" (Kremenchuk, Ukraine) with maleic anhydride was studied. The influence of maleic anhydride amount, process duration, and temperature on the main physical and mechanical characteristics of modified bitumen was studied. The optimal amount of maleic anhydride introduction to bitumen was established. It is found that 2 wt. % maleic anhydride allows to increase the softening temperature of the modified bitumen (from 46 °C to 52 °C). Adhesion to crushed stone also increases (from 2.5 points to 4.5 points) and other indicators improve. Sufficient time to modify the bitumen with maleic anhydride was 30 minutes. The optimum modification temperature for obtaining the modified bitumen with maleic anhydride is 130 °C. Increasing the temperature of the modification has a negative effect on the final physical and mechanical properties of the binder.

Analysis of Selected Properties of Injection Moulded Sustainable Biocomposites from Poly(Butylene Succinate) and Wheat Bran

The paper presents a procedure of the manufacturing and complex analysis of the properties of injection mouldings made of polymeric composites based on the poly(butylene succinate) (PBS) matrix with the addition of a natural filler in the form of wheat bran (WB). The scope of the research included measurements of processing shrinkage and density, analysis of the chemical structure, measurements of the thermal and thermo-mechanical properties (Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TG), Heat Deflection Temperature (HDT), and Vicat Softening Temperature (VST)), and measurements of the mechanical properties (hardness, impact strength, and static tensile test). The measurements were performed using design of experiment (DOE) methods, which made it possible to determine the investigated relationships in the form of polynomials and response surfaces. The mass content of the filler and the extruder screw speed during the production of the biocomposite granulate, which was used for the injection moulding of the test samples, constituted the variable factors adopted in the DOE. The study showed significant differences in the processing, thermal, and mechanical properties studied for individual systems of the DOE.

Influence of biobased polyol type on the properties of polyurethane hotmelt adhesives for footwear joints

Polyurethanes, one of the most used polymers worldwide, are strongly dependent of non-renewable fossil resources. Thus, boosting the production of new polyurethanes based on more sustainable raw materials is crucial to move towards the footwear industry decarbonisation. The aim of this study is to synthesise and characterise reactive hotmelt polyurethanes from biomass and CO2-based polyols as bioadhesives for the footwear industry. The influence of biobased polyols on the polyurethane structure, and therefore, on their final properties was analysed by different experimental techniques such us Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Melting viscosity, Softening temperature and T-peel strength test, in order to assess their viability for the upper to sole bonding process. The results obtained indicated that the incorporation of different amounts of the biobased polyols produces changes in the structure and final performance of the polyurethanes. Therefore, adhesion test carried out by the T-peel test 72 h after the upper -to- sole bonding of the sustainable adhesives show high final adhesion values. These sustainable raw materials provide polyurethane adhesives with additional beneficial non-toxicity and sustainable characteristics, without harming their properties during their useful life.

EFFECT OF REJUVENATORS ON PENETRATION AND SOFTENING POIND OF AGED POLYMER-MODIFIED ROAD BITUMEN

The article describes the effiency of polymer-modified road bitumen regeneration with two types of rejuvenators. Two alternative rejuvenators have been selected aromatic oil Nygen 910 and soft road bitumen V12000. PMB 45/80-55 bitumen, which is used in the upper and lower layers of asphalt pavement, was investigated. During the life time of the asphalt pvement, due to the effects of solar UV radiation, temperature and oxygen, of all the layers of the structure asphalt top layer reaches the highest degree of aging. Short-term and long-term aging were performed to simulate the aging of the bitmen under laboratory conditions. To determine the optimal amount of rejuvenator experiments were performed with 8%, 10% ir 14% rejuvenator by bitumen mass. The effect of rejuvenators were evaluated by studying the main physical properties of bitumen: penetration and softening temperature. Ina n experimental study, aromatic oil was found to be more than 2.5 times more effective than soft bitumen.

Transformation of oil dispersed systems during operation

Using the example of oil road bitumen grades BND 100/130, BND 130/200 and BND 70/100, this article studies the transformation of oil dispersed systems under various logistic schemes of operation. This research focuses on the influence of the conditions for storing road bitumens of different grades on their physical and mechanical properties and group hydrocarbon composition during transportation from the manufacturer to the consumer. The results show that a change in the physical and mechanical properties of road bitumens during high-temperature storage is related to the changes in the group hydrocarbon composition due to the hydrocarbons autooxidation and destabilization of the colloidal structure of dispersal systems. The conditions for storing bitumen with a minimum change in its quality indicators have been determined. It has been established that storage of bitumen under atmospheric conditions allows preserving its original properties without significant changes. There is evidence that nitrogen purging significantly reduces the effect of homolytic processes leading to the transformation of oil dispersed systems during further transportation from the manufacturer to the consumer. Experimental data confirm that of all basic physical and mechanical properties of bitumen, “the depth of penetration of needle” is the most sensitive index, while the “softening temperature” index, frequently used for quality control of bitumen, is inertial. Determining the change in penetration, depending on the duration of storing bitumen, has required formulating a special equation. It has been established that when storing road bitumen at a temperature of 180 ºС, for each hour the index of the penetration depth of the needle at 25 º decreases by 0.8 units. Organizational and technical measures have been determined to ensure the stability of the road bitumen quality during manufacture, storage and transportation to consumers.

The Effect of Mold Conditions on Heat Resistance of Injection-Molded Stereocomplex Polylactide-b-polyethylene Glycol-b-Polylactide Bioplastic

The effect of mold conditions was investigated in terms of mold temperature (30oC and 90oC) and cooling time (30 s and 60 s) on the heat resistance of injection-molded bars for stereocomplex polylactide-b-polyethylene glycol-b-polylactide (scPLA-PEG-PLA). Comparative study was performed for poly(L-lactide) (PLLA) and PLLA-b-PEG-b-PLLA (PLLA-PEG-PLLA). scPLA-PEG-PLA was 90/10 (w/w) PLLA-PEG-PLLA/poly(D-lactide) blend. scPLA-PEG-PLA exhibited the easiest crystallization upon cooling scan as shown by differential scanning calorimetry (DSC). Higher mold-temperature and longer cooling-time induced higher degree of crystallinity as assessed by X-ray diffractometry (XRD) except for PLLA bars. The heat resistance of both PLLA-PEG-PLLA and scPLA-PEG-PLA bars was improved with increased mold-temperature and cooling-time as shown by dynamic mechanical analysis (DMA), vicat softening temperature (VST) and heat distortion-resistance tests except for PLLA bars. In conclusion, the heat resistance of injection-molded bars prepared at 90˚C mold temperature was in the order scPLA-PEG-PLA ] PLLA-PEG-PLLA ] PLLA. The results suggested that flexible PLLA-PEG-PLLA and scPLA-PEG-PLA with high degrees of crystallinity were successfully obtained by injection molding for use as good heat-resistant bioplastic products.

Structure and properties of heat-resistant ABS resins innovated via MSAMI random copolymer

This work proposed an efficient method to synthesize acrylonitrile-butadiene-styrene (ABS) copolymer and α-Methylstyrene (α-MSt)/N-phenylmaleimide (NPMI)/Acrylonitrile (AN) (MSAMI) random copolymer via emulsion polymerization, aiming to combine the excellent heat resistance of MSAMI and numerous advantages of ABS resin including mechanical properties, processing and recyclability. The effects of the MSAMI content and α-MSt/AN ratio on the thermal performance, mechanical properties and the morphology of heat-resistant ABS were investigated by FITR, dynamic mechanical analyses (DMA), Vicat Softening Temperature (VST), Thermogravimetric Analysis (TGA) and Scanning Electron Microscope (SEM). As a result, the heat-resistant of ABS resin was obviously enhanced by MSAMI, and its glass transition temperature (Tg) could be extended with the increase of NPMI content. The Tg could reach 173°C when NPMI content was 20% at the same trend as the VST. Synthetically, the contradiction between the heat resistance and mechanical properties of ABS resin reached a good balance when the NPMI content was 15% and α-MSt/AN ratio was 69/31. In SEM, the fracture morphology of the heat-resistant ABS resin was gradually tended to be smooth with the increase of the NPMI content. Therefore, the MSAMI random copolymer was successful prepared, which provided insight for the synthesis of heat-resistant modifiers and promoted the potential application of heat-resistant modifiers in automobiles and aircraft.

Estimating the effect of aqueous cationic latex from the class of thermal elastic plastics on the properties of bitumen emulsions

To produce cationic bitumen emulsions, bitumen is used, whose penetration is not lower than 90 mm-1. Such bitumen has a small plasticity interval, which leads to a deterioration in its heat resistance at elevated temperatures and narrows the scope of application of emulsions based on it. Based on the review of emulsion modification methods, the modification has been proposed that involves mixing the finished bitumen emulsions with aqueous cationic latex. The process of interaction between a bituminous emulsion and an aqueous cationic latex has been considered. A mechanism for the disintegration of the modified bitumen emulsion on the surface of mineral materials was proposed. The emulsifiers have been selected and the composition of the aqueous phase has been chosen based on the analysis of surface tension isotherms. The influence of the modification on the properties of bitumen emulsions was investigated. It was established that the main physicochemical characteristics of the interphase surface accept similar values for the aqueous phase and emulsions based on it. It has been proven that the introduction of aqueous cationic latex quite moderately affects the basic physical-mechanical properties of emulsions, which makes it possible not to change the main technological parameters when using them. It was established that increasing the concentration of the polymer in the emulsion has a positive effect on the physical-mechanical properties of the binder. With an increase in the concentration of the polymer to 6 % the softening temperature increases by 16 °C, elasticity is 74 %, and the holding capacity at minus 25 °C is approaching 100 %. Improving the physical-mechanical properties of residual binder as a result of emulsion modification could increase the durability of layers in a roadbed based on bitumen emulsions and expand the scope of their application in the construction and repair of motorways