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This paper presents the experimental study of mechanical and thermal properties of organically modified montmorillonite clay (Nanoclay) (0, 1, 2, 3, 4 and 5 wt.%) in the vinyl ester matrix by ultrasonic stirrer. The changes in mechanical properties are investigated by using tensile and impact testing machine. It was found that the addition of nanoclay particles significantly improved tensile properties of pure vinyl ester, but impact properties of pure vinyl ester were affected negatively with the nanoclay content in the nanocomposite. It was found that the absorbed energy and impact resistance of the nanocomposites decreased with increasing the nanoclay content. DSC curves showed the glass transition temperature change in the nanoclay reinforced vinyl ester nanocomposites as compared to the pure vinyl ester. XRD analysis was performed to identify the structure of nanocomposites. SEM results showed the change in fracture surface morphology of nanoclay reinforced vinyl ester nanocomposite. Also, homogeneous distribution of nanoclays in the matrix was showed by SEM micrographs. This observation helped in identifying the morphology of the nanocaly in the vinyl ester matrix.

Thixotropy can be regarded as the loss of viscosity in a paint or other material that is brought about by mechanical agitation, and where the viscosity continues to decrease provided that this disturbance is continued for a period of time. Conversely, when the mechanical force is removed, the material then increases in viscosity and this recovery toward the initial structure continues to take place over a period of time. Sometimes the time dependency of the viscosity is vanishingly small so that the material is then properly referred to as pseudoplastic. In most of the literature, however, it is not usually possible to differentiate between thixotropy and true pseudoplasticity and therefore both kinds of structure are included in this review as they each are destroyed by mechanical agitation and recover when this is discontinued.

This research deals with a new kind of nanopigment, obtained from the combination of organic dyes and layered nanoclays, that the authors call nanoclay‐colorant pigment (NCP). Whilst they have already been employed in inks and coatings, to date these nanopigments have not been used as pigments for polymers. The existing lack of knowledge surrounding them must be redressed in order to bridge the gap between current academic studies and commercial exploitation. Therefore, the main purpose of this paper is to examine the hitherto unknown aspects of the NCP, which relate specifically to their applicability as a new type of colorant for polymers.

A blue NCP has been prepared at the laboratory according to the patented method of synthesis (patent WO0104216), using methylene blue and montmorillonite nanoclay. It has then been applied to a thermoplastic polymer (linear low‐density polyethylene – LLDPE) to obtain a coloured sample. Furthermore, samples with the same polymer but using conventional blue colorants have been prepared under the same processing conditions. The mechanical, thermal and colorimetric properties of these materials have been compared.

The thermal stability of the sample coloured with NCP is reduced to some extent, while the mechanical strength is slightly increased. Moreover, this sample has better colour performance than the conventionally pigmented samples.

In this paper, a blue NCP has been synthesised and successfully employed with polyethylene and the obtained sample shows better colour performance than polyethylene with conventional pigments.

Rheox, Inc., is a leading producer of rheological additives. The company's products are used in a wide variety of industries including those involved in the formulation and production of paints, resins, ink, adhesives and sealants.

A practical guide to rheological additives entitled “NL Rheology Handbook” is available from NL Chemicals (UK) Ltd, St. Ann's House, Wilmslow, Cheshire SK9 1HG. Tel: 0625 529511.

This study aims to describe the preparation of antimicrobial material usable in 3D printing of medical devices. Despite the wealth of technological progress at the time of the crisis caused by SARS-CoV-2 virus: Virus that causes current Pandemic situation (COVID-19), the global population had long been exposed beforehand to an acute absence of essential medical devices. As a response, a new type of composite materials intended for rapid prototyping, based on layered silicate saponite (Sap), antimicrobial dye phloxine B (PhB) and thermoplastics, has been recently developed.

Sap was modified with a cationic surfactant and subsequently functionalized with PhB. The hybrid material in powder form was then grounded with polyethylene terephthalate-glycol (PETG) or polylactic acid (PLA) in a precisely defined weight ratio and extruded into printing filaments. The stability and level of cytotoxicity of these materials in various physiological environments simulating the human body have been studied. The applicability of these materials in bacteria and a yeast-infected environment was evaluated.

Ideal content of the hybrid material, with respect to thermoplastic, was 15 weight %. Optimal printing temperature and speed, with respect to maintaining antimicrobial activity of the prepared materials, were T = 215°C at 50 mm/s for PETG/SapPhB and T = 230°C at 40 mm/s for PLA/SapPhB. 3 D-printed air filters made of these materials could keep inner air flow at 63.5% and 76.8% of the original value for the PLA/SapPhB and PETG/SapPhB, respectively, whereas the same components made without PhB had a 100% reduction of airflow.

The designed materials can be used for rapid prototyping of medical devices.

The new materials have been immediately used in the construction of an emergency lung ventilator, Q-vent, which has been used in different countries during the COVID-19 crisis.

This paper aims to exploit shape memory polymer (SMP) composite as multifunctional coatings for protecting substrates from surface wear and bacterial. The efficiency of added nano or micro-sized particles in enhancing the properties of SMP was investigated. This study also attempts to use a low-cost and effective spraying approach to fabricate the coatings. The coatings are expected to have good conformability with the substrate and deliver multi-functional performance, such as wrinkle free, wear resistance, thermal stability and antimicrobial property.

High-performance SMP composite coatings or thin films were fabricated by a home-made continuous spray-deposition system. The morphologies of the coatings were studied using the scanning electron microscope and the transmission electron microscope. The abrasion properties were evaluated by Taber Abraser test, and thermo-gravimetric analysis was carried out to investigate the thermal properties of prepared composites. The antimicrobial property was determined by the inhibition zone method using E. coli. The thermally responsive shape memory effect of the resulting composites was also characterized.

The morphology analysis indicated that the nanoclay was distributed on the surface of the coating which resulted in a significant improvement of the wear property. The wear resistance of the coatings with nanoclay was improved as much as 40 per cent compared with that of the control sample. The thermo-gravimetric analysis revealed that the weight loss rate of composites with nanoclay was dropped over 40 per cent. The SMP coating with zinc oxide (ZnO) showed excellent antimicrobial effect. The shape recovery effect of SMP/nanoclay and SMP/ZnO composites can be triggered by external heating and the composites can reach a full shape recovery within 60 s.

This study proposed a continuous spray-deposition fabrication of SMP composite coatings, which provides a new avenue to prepare novel multi-functional coatings with low cost.

Most studies have emphasized on the sole property of SMP composites. Herein, a novel SMP composite coating which could deliver multi-functionality such as wrinkle free, wear resistance, thermal stability and antimicrobial property was proposed.

The purpose of this paper is to study the corrosion protective properties of modified urea and/or thiourea formaldehyde resins for steel surface.

Three butyl alcohol modified amino resins were laboratory prepared. The three modified resins were characterized using thermal gravimetric analysis and infrared; the solid content and refractive index of each were also measured.

The resins that contain both nitrogen and sulphur have excellent corrosion inhibitive activity compared with that containing nitrogen only.

The modified resins were based on urea formaldehyde resin, mixed urea and thiourea formaldehyde resin and thiourea formaldehyde resin, respectively.

The prepared resins were introduced in different coating formulations based on short‐oil alkyd resin, medium‐oil alkyd resin and plasticized chlorinated rubber. They were then tested and evaluated for corrosion protection of steel surfaces.

All the prepared resins show promising results for corrosion protection of steel surfaces.

The purpose of this paper is to study the effect of the nano tube fillers on the corrosion protection properties of the self-curing epoxy (SEP) coatings.

The self-curing epoxy (SEP) resin was synthesized via a reaction between diisopropoxy-bis ethylacetoacetato titanate and the epoxy resin. Halloysite nanotubes (HNTs) was surface modified by grafting (3-glycidoxypropyl) trimethoxysilane to obtain modified HNTs (mHNTs). The HNTs and mHNTs are used as nano tube fillers for the SEP coating. The thermal stability of the coatings was assessed via thermo-gravimetric analysis. The field-emission scanning electron microscopy (SEM) was conducted to analyze the surfaces and cross sections of the coatings. The anticorrosive efficiencies of the coatings were investigated by electrochemical measurements and a neutral salt spray test.

The results demonstrated that the additions of HNTs and mHNTs have little effect on the thermal degradation temperature of the SEP coating. However, the addition of the nanotubes reduced the corrosion resistance of the SEP coating.

The SEP coating itself showed excellent corrosion resistance without any reinforcement particles and is hence promising for application in the heavy-duty anticorrosion field of heat exchangers.

The purpose of this paper is to reinforce the selective laser sintering (SLS) parts of nylon‐12 using organically modified montmorillonite (OMMT).

A dissolution‐precipitation process is developed to prepare an OMMT/nylon‐12 composite powder (3 wt% OMMT). X‐ray diffraction (XRD) was used to characterize nanostructure features. The dispersion of OMMT in the nylon‐12 matrix was observed by scanning electron microscope (SEM). The effect of OMMT on the thermal properties of nylon‐12 was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The mechanical properties of the SLS parts made from the composite powder and neat nylon‐12 powder were measured and compared.

The X‐ray diffraction and SEM results indicate that the OMMT is intercalated by nylon‐12 molecular chains and uniformly dispersed in the nylon‐12 matrix during the dissolution‐precipitation process, and thus the OMMT/nylon‐12 intercalated nanocomposites are formed. The DSC and TGA results show that the OMMT can increase the melting enthalpy, relative crystalline content, crystallization temperature and thermal stability of nylon‐12. The tensile strength, tensile modulus, flexural strength, flexural modulus and impact strength of the SLS specimens made from the composite powder are 23.2, 31.7, 18.7, 32.4 and 8.4 percent higher than those of neat nylon‐12 SLS specimens, respectively, while the elongation at break decreases by 17.5 percent.

The conclusion of forming intercalated nanocomposites was drawn from the XRD results in the present work. Further work should be done to observe the nanostructures of the materials by transmission electron microscope.

A dissolution‐precipitation process was used to prepare OMMT/nylon‐12 composite powders for SLS process. During the preparation process the OMMT could be intercalated by nylon‐12 molecular chains and uniformly dispersed in the nylon‐12 matrix, thus forming the OMMT/nylon‐12 intercalated nanocomposites. Therefore, the mechanical and thermal properties of nylon‐12 SLS parts were enhanced.