Metal oxide nanoparticles are the subject of current interest because of their unusual optical, electronic, and magnetic properties. In this work, cobalt zinc ferrite (Co0.3Zn0.7Fe2O4) nanoparticles have been synthesized successfully through redox chemical reaction in aqueous solution. The synthesized Co0.3Zn0.7Fe2O4 nanoparticles have been used for the preparation of homogenous polyvinyl acetate-based nanocomposite (Co0.3Zn0.7Fe2O4/PVAc) via in situ emulsion polymerization method. Structural, morphological and magnetic properties of the products were determined and characterized in detail by X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The XRD patterns of the Co0.3Zn0.7Fe2O4 confirmed that the formed nanoparticles are single crystalline. According to TEM micrographs, the synthesized Co0.3Zn0.7Fe2O4 nanoparticles had nano-needle morphology with an average particle size of 20 nm. The calculated coefficient of variation (CV) of nanoparticles diameters obtained by TEM micrographs was 16.77. The Co0.3Zn0.7Fe2O4 nanoparticles were dispersed almost uniformly in the polymer matrix as was proved by SEM technique. The magnetic parameters of the samples, such as saturation magnetization (M s) and coercivity (H c) were measured, as well. Magnetization measurements indicated that the saturation magnetization of synthesized Co0.3Zn0.7Fe2O4/PVAc nanocomposites was markedly less than that of Co0.3Zn0.7Fe2O4 magnetic nanoparticles. However, the nanocompoites exhibited super-paramagnetic behavior at room temperature under an applied magnetic field.

This study focused on developing and characterizing an emulsion paint formulated from a copolymer binder of polyvinyl acetate- hydroxylated guna seed oil (PVAc/HGSO) and compared with paint made from conventional polyvinyl acetate (PVAc) binder. Seed oil from guna was extracted mechanically using cold press method, and the extracted guna oil were successively subjected to epoxidation and hydroxylation reaction processes. The hydroxylated guna seed oil (HGSO) was copolymerised with conventional polyvinyl acetate in different ratio of 10 to 70% of hydroxylated oil, to formulate a novel PVAc/HGSO copolymer binder. The formulated copolymer binder was characterised, and compared with the standard inorder to ascertain the better blend ratio that will be suitable for paint production. The better blend copolymer binder was used in production of an emulsion paint. The physico-chemical parameters on the formulated emulsion paint were compared with paint formulated using only PVAc as a binder and acceptable value in the coating industry. The novel formulated emulsion paint found to be increased in gloss, adhesion and flexibility, which are major setback in paint produced using conventional PVAc only as a binder.

With the development of composite manufacturing processes, such as low-pressure compression moulding of sheet moulding compounds (SMC), resin transfer moulding (RTM) and vacuum infusion moulding processes, low-shrinkage resin which can be processed at low temperatures have attracted considerable interest from the composite industry. In this paper the effect of polyvinyl acetate (PVAc) as a low profile additive (LPA) on shrinkage control of an iso unsaturated polyester resin has been investigated and cure behaviour, morphology and mechanical properties of this system has been studied. Our studies show that the maximum exothermic temperature and the rate of cure decreases with increasing the PVAc concentration. The PVAc content has a significant effect on the resin viscosity. It was found that there are two transitions for UP resin containing PVAc cured at low temperatures. The PVAc content is effective for shrinkage control only in a concentration between these two transitions. Experimental results showed that the mechanical properties of this system decreases by increasing the PVAc content.

In this research, the effect of Polyvinyl acetate (PVAc) adhesive modified by carbon nanofibers (CNF) reinforcement were studied using three levels (0%, 0. 4%, 1. 5%) of carbon nanofibers on the strength properties of joints commonly used in the furniture industry. Modified carbon nanofibers were used as chemically modified surface to improve the dispersion in polymer matrix. The test specimens were made using cut out medium density fiber board (MDF) pieces with required dimensions and dowel wooden with 6, 8 and 10 mm in diameter, and penetration depth at three levels using polyvinyl acetate adhesive reinforced with modified carbon modified nanofiber. Totally, 27 treatments and three replication were used. The evaluation of the bending moment capacity of test specimens made with freshly formulated adhesive and the effect of other variables was performed on the joints made under tensile loading at a speed of 3 mm/min. The results showed that increasing the percentage of carbon nanofibers, the diameter of the wooden dowel and the penetration depth and the moment capacity compared to the control samples was increased by 1. 6, 1. 5 and 1. 3 times, respectively. The 0. 4% w/w carbon nanofibers, 10 mm diameter and L3 wooden dowel penetration depth had the greatest effect on the strength of the joints.

It is very helpful to guide design production and processing conditions for polymer-based inorganic or organic nano-composites by investigating their rheology. In this study, an intercalated nano-composite of montmorillonite (MMT)-dioctadecyl dimethyl ammonium bromide (DOAB) was added and reacted with vinyl acetate (VAc) to form the exfoliated nano-composite of polyvinyl acetate (PVAc)-MMT-DOAB through five different synthesis processes. The MMT-DOAB was exfoliated into nano-particles of layers or sheets and dispersed randomly in PVAc matrix. The different synthesis processes affected the dispersion and apparent viscosity of PVAc and PVAc-MMT-DOAB. With the polymerization time shortening and the water decreasing, the dispersion got bad and the apparent viscosity increased. PVAc and PVAc-MMT-DOAB were pseudo-plastic non-Newtonian fluids and both possessed the normal stress effect (Weissenberg effect) that is also called the pole-climbing phenomenon. By the help of the apparent viscosity analyzed using the power-law function equation, Newtonian fluid flow equation and Cross-Williamson model viscous equation, the different synthesis processes and MMT–DOAB had a certain effect on the rheology of PVAc and PVAc-MMT-DOAB. With the change of different synthesis processes and the increase of MMT-DOAB content in the synthesis system, the estimated molecular weight of PVAc–MMT–DOAB was also increased accordingly.

In this study, the effect of open time and hardener content was investigated on bending strength of finger jointed made of three wood species; beech, fir and poplar. For this purpose, wooden samples with dimensions of 25mm width, 35 mm thickness and 350 mm length were prepared from three species. After three weeks of storage in climate room, in order to form finger joint pattern, samples were cut at the half of length. Then, the finger joint pattern was done in new exposed cross sections of the samples. After that, the joints were bonded with three PVAc glue types; pure, with 10% and with 20 % hardener. The second variable of study was open time that was controlled in two levels of 2 and 4 minutes. The close time and press time were constant which were adjusted on 2 and 30 minutes, respectively. The joints were pressed in a special wooden frame by hand clamp. After making joints, they were stored in climate room for three weeks and then the three point bending test was carried out according to ISO 10983. The results showed that by adding isocyanate hardener up to 20%, the bending strength increases significantly. The longer open time could not improve bending strength. On the contrary, it caused strength dropping in some treats but these changes were not significant. The strength of joints made with poplar wood was lower than beech and fir, although this difference was not statistically significant. Finally, the best condition for making this joint was determined by application of 2 min open time and using 10 % PU resin as a hardener.