This paper discusses the role of metal oxides (MeO) in the cross-linking process and useful properties of chloroprene and butadiene rubber (CR/BR) blends. Iron(III) oxide (Fe₂O₃), iron(II,III) oxide (Fe₃O₄), silver(I) oxide (Ag₂O) or zinc oxide were used. It has found that every proposed metal oxide can be used as a cross-linking agent of the CR/BR blends. The degree of cross-linking was evaluated by means of vulcametric parameters, equilibrium swelling in selected solvents and Mooney–Rivlin elasticity constants. The properties of the cured CR/BR products, such as tensile strength, stress at elongation, tension set under constant elongation and compression set, were also investigated. The results revealed that all CR/BR/MeO vulcanizates were characterized by a high cross-linking degree and satisfying mechanical properties. The most important advantage of obtained rubber goods is very high resistance to flame. The increase in the oxygen index value for the CR/BR/Fe₂O₃, CR/BR/Fe₃O₄ and CR/BR/Ag₂O vulcanizates compared to the standard cross-linked chloroprene rubber showed that presented metal oxides provided a positive effect on the resistance to flame of the new CR/BR/MeO composites. Satisfactory properties of the studied blends are related to the presence of the interelastomer bonding of both rubbers in the compositions.

The role of iron(III) oxide (Fe₂O₃) in the cross-linking process, structure and functional properties of chloroprene and butadiene rubber (CR/BR) blends was studied. The unconventional elastomeric blends containing chloroprene and butadiene rubbers of different mass ratios, cross-linked with iron(III) oxide, have been studied. It has found that the iron(III) oxide could be used as a cross-linking agent in CR/BR blend and the curing degree depends largely on the composition of the blends. These results indicate that the curing degree of the blends is increased with increasing amount of chloroprene rubber. It is very interesting to note that the addition of butadiene rubber to chloroprene rubber improved the mechanical properties of the resulting vulcanizates. The resulting CR/BR/Fe₂O₃ vulcanizates were characterized by good mechanical properties. Surprisingly, the selected vulcanizates containing chloroprene and butadiene rubbers had a 40% greater tensile strength compared to vulcanizates containing only chloroprene rubber. The amount of iron(III) oxide as the curing agent slightly affected the curing degree and mechanical properties of the resulting rubber materials. This should probably be linked to the interelastomer reaction between the chloroprene and butadiene rubbers occurring in the presence of iron(III) oxide at an elevated temperature. Interelastomer reactions between both elastomers may lead to improved homogeneity and miscibility of the test systems. Additionally, it has been found that the CR/BR blends cross-linked with Fe₂O₃ were characterized by a high flame resistance. The undoubtable advantages of the proposed technology are its simplicity, low cost and incombustibility.

This paper discusses the curing and properties of chloroprene and butadiene rubber (CR/BR) blends cross-linked with copper(I) oxide (Cu₂O) or copper(II) oxide (CuO). The results revealed that the cross-linking degree of CR/BR blends decreased with the increasing amount of butadiene rubber (BR) in the blends. The mechanical properties of cured CR/BR blends depended on the proportion of elastomers in blends, as well as on the type and amount of the cross-linking agent (Cu₂O, CuO). The cross-linking of CR/BR/Cu₂O or CR/BR/CuO blends followed according to cationic mechanism, using Lewis acid, copper(I) chloride (CuCl) or copper(II) chloride (CuCl₂) generated in situ. Additionally, the prepared compositions, both unfilled and filled, were characterized by very high resistance to flame.

The study explores the novel use of oak bark (Quercus cortex) as a bio-filler in elastomeric composites, aligning with the global trend of plant-based biocomposites. Both modified and unmodified oak bark were investigated for their impact on the physicochemical properties of natural rubber (NR) composites. The bio-filler modified with n-octadecyltrimethoxysilane exhibited enhanced dispersion and reduced aggregates in the elastomeric matrix. NR composites containing more than 20 phr of unmodified and modified oak bark demonstrated an increased degree of cross-linking (α_c > 0.21). Mechanical properties were optimal at 10–15 phr of oak bark and the sample with modified bio-filler (10 phr) achieved the highest tensile strength (15.8 MPa). Silanization and the addition of the bio-filler increased the hardness of vulcanizates. The incorporation of oak bark improved aging resistance at least two-fold due to phenolic derivatives with antioxidant properties. Hydrophobicity decreased with added bark, but silanization reversed the trend, making samples with a high content of oak bark the most hydrophobic (contact angle: 129°). Overall, oak bark shows promise as an eco-friendly, anti-aging filler in elastomeric composites, with modification enhancing compatibility and hydrophobicity.

This paper discusses the curing behaviors, mechanical and dynamical properties of composites containing chloroprene rubber (CR) and butadiene rubber (BR) reinforced with mineral fillers. The iron(III) oxide nanoparticles were used as a crosslinking agent of the CR/BR blends. The research aimed to evaluate the effectiveness of nano-iron(III) oxide (nano-Fe₂O₃) as a new crosslinking agent while producing elastomeric materials with good mechanical properties and reduced flammability. The CR/BR (chloroprene rubber/butadiene rubber) blends were filled with silicas from natural resources (chalcedony, Neuburg silica earth) or silicas used in elastomer technology in many fields (aerosil, ultrasil). The results revealed that all composites were characterized by satisfactory tensile strength, tear resistance, and high resistance to fire. The filler dispersion in the elastomer matrix was carried out by using scanning electron microscopy (SEM), while the possibility of the filler–filler or filler–rubber interaction in the designed compositions was determined using the Payne effect and the Mullins effect.

The aim of the study was to produce new elastomeric materials containing butyl rubber (IIR) filled with silica and phyllosilicates (vermiculite, montmorillonite, perlite or halloysite tubes) with enhanced hydrophobicity and barrier properties and reduced chemical degradation. It was found that the filler type had a significant impact on the degree of cross-linking of butyl rubber and the properties of its vulcanizates. The highest degree of cross-linking and the highest mechanical strength were achieved for IIR composites filled with Arsil with perlite or halloysite tubes. The highest surface hydrophobicity (119°) was confirmed for the IIR vulcanizates with Arsil and montmorillonite. All tested samples showed high barrier properties because both the gas diffusion rate coefficient and the permeability coefficient reached low values. Both unfilled and filled IIR vulcanizates retained chemical resistance in contact with methanol for 480 min. Hour-long contact of a polar solvent (methanol) with each of the vulcanizates did not cause material degradation, while the presence of a non-polar solvent (n-heptane) worsened the mechanical parameters by up to 80%. However, the presence of fillers reduced the chemical degradation of vulcanizates (in the case of cured IIR filled with Arsil and halloysite tubes by 40% compared to the composite without fillers).