This study investigates the use of POLYMER BLENDS [polyvinyl acetate (PVA) and polyvinyl chloride (PVC)] to modify and improve the rheological properties of asphalt material and make it more resistant to environmental conditions such as acid rain and aging when used in road paving. Specific proportions of the POLYMER blend [polyvinyl acetate (PVA): polyvinyl chloride (PVC)] were added to the asphalt with the addition of 1% of (nano-sulfur) at a temperature ranging between (150-170) °C for one hour for each sample. Rheological measurements of the original and modified asphalt were performed, including penetration, ductility, softening point, and penetration index, in addition to measuring the Marshall coefficient, aging test, and scanning electron microscope (SEM) for some selected samples and comparing them with normal asphalt. The results indicate that the asphalt modified with the POLYMER blend and nano-sulfur resists environmental conditions of different temperatures, acid rain, and aging more than normal asphalt, making it a suitable candidate for road paving applications.

Application of supramolecular POLYMER blending in preparation of materials with adjustable mechanical properties is addressed. It is anticipated that the microstructure and properties of POLYMER BLENDS are drastically controlled by the inter-molecular interactions. On this basis, the effect of strongly dimerising ureidopyrimidinone end groups (UPy) with the capability of quadruple hydrogen bonding array formation on the material properties of polycaprolactone/ polyhydrofuran supramolecular POLYMER BLENDS has been studied. The mechanical test results revealed that the supramolecular strategy resulted in up to 110% and 500% increase in tensile strength and Young's modulus, respectively. Observation of a single glass transition temperature in DSC traces of the BLENDS shows that phase compatibility improved significantly upon blending.

Due to immiscibility of the most POLYMER BLENDS, the present article relies on review the theories and relation between morphology and rheology of immiscible POLYMER BLENDS. The results of morphological investigation revealed that the ultimate structure of immiscible POLYMER BLENDS relates to two parameters of viscosity ratio and capillary number. Capillary number connected to matrix viscosity, strain rate and interfacial tension as well. The other parameter which affects on drop break-up and morphology of POLYMER BLENDS is type of flow. The outcomes indicated that droplet breaks-up in elongation flow easier than shear flow. The models of Palierne, Coran, Jarzebski and Doi- Ohta are very famous models in correlation between rheology and morphology of immiscible POLYMER BLENDS. It was illustrated in Doi- Ohta model the more differences in first normal stresses of immiscible POLYMER BLENDS the smaller of droplet size of dispersed phase. In Palierne model, the complex modulus of immiscible POLYMER BLENDS relates to droplet diameter and interfacial tension.

Blending of POLYMERs is one of the useful methods for developing POLYMERic materials with improved properties or creating special properties in POLYMERs. The mixture of some POLYMERs is completely or partially miscible, but the mixture of many POLYMERs is immiscible and their microstructure will be multiphase due to high molecular weight and undesirable interactions. Extensive research has been conducted on the development of blend compatibilization approaches. Surface modification of POLYMERs, addition of block coPOLYMERs, reactive compatibilization, crosslinking, interpenetrating networks, and more recently the addition of fillers in the micro and nano dimensions are some of the methods used to improve the compatibility of mixtures. The reduction of modulus and its related properties, when adding POLYMERic compatibilizers has caused researchers to pay more attention to nanoparticles and their compatibility effect. Compatibility mechanisms of POLYMER BLENDS using nanoparticles can be divided into two modes based on their location in the blend. First, nanoparticles in the matrix phase, by forming a three-dimensional network and increasing the viscosity, apply more stress to the dispersed phase, reduce the size of the dispersed regions, and then reduce the coalescence phenomena of dispersed particles. In the second case, the nanoparticles, by locating at the interface between the matrix and dispersed phases reduce the interfacial stress and increase the interfacial adhesion. Also, in this case, they prevent the integration of scattered phase droplets. In this paper, the effect of nanoparticle compatibility on POLYMER BLENDS, mechanisms, and the affecting structural factors are reviewed.

Damage in asphalt pavements due to repetitive stresses and strains caused by both traffic loading and environmental factors can manifest itself as fatigue and thermal cracking, respectively. Cracking is considered as a primary distress mechanism in asphalt pavements. Many studies have been carried out on resolving these distresses. One of these ways is the use of POLYMER modifiers to improve the properties of asphalt binder and asphalt mixtures. Therefore, this research was conducted to study the effects of domestic POLYMERs (with trade names of SBR and PP) in equal proportions on the fatigue properties of asphalt mixtures compared to expensive imported POLYMER (called SBS). Accordingly, four-point beam fatigue and indirect resilient modulus tests were carried out. It was found that combination of PP and SBR leads to better preservation of fatigue performance of modifed mixes and increases the fatigue life up to 50% compared to SBS-modified mix. Consequently, such POLYMERs combination can be more beneficial than using SBS POLYMER.