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Waterborne polyurethane dispersions (PUDs) continue to show growth in commercial usage due to the ever increasing environmental legislation to reduce VOC in coating and adhesive materials. The transition from solvent‐based to waterborne has also been facilitated by advances in both the chemistry and technology employed and the formulation expertise required. This has resulted in coating performance that cannot only match but in some cases surpass their solvent‐based counterparts. This paper gives an overview of PUDs and introduces urethane/acrylic hybrids, giving an insight into the chemistry and technology. Particular emphasis is given to new developments and the application areas where they are finding increasing use. Some formulating techniques are also illustrated.

The effects of polyol types, polyol molecular weights, NCO/OH molar ratio, solvent types, and resin solid contents of the one‐part ambient temperature curing adhesives were studied. The results showed that the one‐part ambient temperature curing polyurethane prepared had fast rate of setting and good bonding, meeting the requirements of a typical structural adhesive.

The purpose of this work is to develop flexible as well as rigid polyurethane coating by using mixed polyol. It is developed by using low cost reactant such as polyether and introducing branching in it.

Radiation curable branched polyurethanes were synthesised. In this work, branched polyol was synthesised by using trimethylol propane (TMP) and reacted with adipic acid (AA), neopentyl glycol (NPG) (polyester) and polypropylene glycol (PPG) (polyether). These branched polyols were developed by varying ratio of polyether to polyester from 20:80, 40:60 and 55:45. These branched polyols were further reacted with isophorane di isocyanate (IPDI) and hydroxy ethyl metha acrylate (HEMA) to get vinyl terminated prepolymer.

The branched polyol due to presence of polyether offers excellent flexibility and polyester which provides excellent scratch, adhesion, and tensile strength. Use of reactive diluents is avoided, and its role is compensated by polyether in all systems, which takes care of reducing viscosity and improves flow and levelling properties.

Synthesis of branched polyol using polyesters and polyethers is more beneficial as it offers advantage of its combined property.

The polyurethane acrylate due to its polyol combination, branching and cross linking offers enhanced coating properties and can be used for various coating applications.

B.I.C.C. new patents officer Following the death of R. L. Cleaver, British Insulated Callender's Cables Ltd. have named H. H. Daker, B.SC., A.M.I.E.E., C.P. A., as his successor.

The purpose of this paper is to synthesize and characterize a series of alicyclic two-component waterborne polyurethane (2K-WPU) which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion.

The appearances of aqueous dispersions and 2K-WPU films were observed by photographs. The micromorphology of alicyclic polyisocyanate aqueous dispersion was examined by scanning electron microscopy (SEM). The molecule structures of WPU were studied by Fourier transform infrared (FTIR). The effect of NCO:OH molar ratio of two components and trimethylolpropane (TMP) content on the thermal stability, mechanical and water resistance properties of 2K-WPU films was studied.

It was found by SEM that alicyclic polyisocyanate particles in aqueous dispersion showed a kind of spherical particle appearance, in which hydrophobic polyisocyanate was encapsulated by hydrophilic ether linkages segment. FTIR showed that WPU was polymerized through mixture of polyisocyanate component and hydroxyl component and increasing NCO:OH molar ratio of two components from 1.1:1 to 1.5:1 had increased the content of urea, urethane and allophanate of 2K-WPU films. Increasing NCO:OH molar ratio had improved the mechanical and thermal properties of the 2K-WPU film, but the water resistance of the 2K-WPU film increased first and then weakened. Increasing TMP contents from 1 to 0.75 mol for 1:5 system had improved the mechanical, thermal and water resistance properties of the 2K-WPU film.

The investigation established a method to prepare alicyclic 2K-WPU which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. The prepared 2K-WPU film could be applied in the field of waterborne surface coating, e.g. textile, wood and synthetic leather surfaces (Hasan et al., 2017; Akindoyo et al., 2016).

The paper established a method to synthesize alicyclic two-component 2K-WPU. The effect of NCO:OH molar ratio and TMP content on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

Poly(ethylene terephthalate) (PET) waste from soft drink bottles was incorporated into palm olein alkyd to produce new polyol for use in polyurethane resins as surface protection on metal surfaces.

Alkyd was prepared from palm olein, glycerol and phthalic anhydride. PET underwent simultaneous glycolysis and transesterification reactions with the alkyd. Varying the amount of PET has led to polyols with different viscosities. Polyurethane resins were produced by reacting the polyols with toluene diisocyanate. The resins were coated on mild steel panels and cured. Performances of the cured films were tested.

The polyurethanes (PU) resin cured to a harder film with better thermal stability. Films showed excellent adhesion properties, while higher content of PET exhibited higher pencil hardness, better water, salt, acid and alkali resistance.

Other vegetable oils could also be used. The alkyd structure could be changed by formulation to have different functionality and the ability to incorporate higher amount of PET waste. Rate of glycolysis of PET could be increased by higher amount of ethylene glycol.

This method has managed to use waste PET in producing new polyol and PU resins. The cured films exhibit good mechanical and chemical properties, as well as excellent adhesion and thermal stability.

The non-biodegradable PET has created environmental pollution problems connected to littering and illegal landfilling. It has become necessary to pay greater attention to recycling PET bottles for obtaining valuable products.

This approach is different from the earlier reports, where PET was recycled to recover the raw materials.

This paper presents a solder joint engineering reliability model — Solder Reliability Solutions** (SRS) — and its application to surface mount area‐array and chip‐scale assemblies. The model is validated by failure data from 33 accelerated thermal cycling tests, and test vehicles covering several generations of component, assembly and circuit board technologies and a variety of test conditions. The SRS model has been implemented as a PC‐based design‐for‐reliabilltytool that enables rapid assessment of assembly reliability in the early stages of product development.

The aim is to present temperature fatigue model constants for lead‐free tin‐silver‐copper solder derived from test data and demonstrate the validity of the model using published experimental results.

Temperature cycle fatigue life data were collected from a controlled set of tests using ceramic leadless chip carriers. Using a regression algorithm, temperature cycle fatigue model constants were derived from fatigue life data. The model was then applied to a variety of package formats including ball grid arrays, quad flatpack and thin small outline packages to determine the validity of the model and constants.

The temperature cycle fatigue life experimental data were found to be in good agreement with the model with the derived model constants for various package types. Using this model, engineers can determine acceleration factors between test and field temperature cycle conditions.

The technology has been used to ensure inner layer designs with nominal dimensions after the lamination stage. Further, development work should be undertaken to collate measured data from other parts of the PCB manufacturing process and model the material movement around all registration critical processes.

The paper details a temperature cycle fatigue life model and constants that allow engineers to predict field life expectancy and determine the acceleration factor between temperature cycle testing and field use conditions.

Aims to show that with careful modelling, the fatigue life of solder joints of identical geometry and microstructure can be predicted very accurately (through empirical correlations) under different environmental test or field use conditions. Here, on the TI 144 chip ‐scale package, the empirical correlation for fatigue life developed under thermal cycling conditions is used to predict the life under power cycling. This accurate model has served as the physical basis which in to demonstrate quantitatively the equivalence of thermal cycling and power cycling as valid accelerated life tests. Describes the great importance of spatial refinement, temporal refinement, and accurate boundary conditions, including the often ignored natural convection boundary conditions, and their effect on predicted life.

Conventional lecture-based educational approaches alone might not be able to portray the complexity of disaster risk management practice and its real-life dynamics. One work-integrated learning practice that can give students practical work-related experiences is simulation-based learning. However, there is a limited discourse on simulation-based learning in disaster risk management education at the tertiary level. As tertiary education plays a crucial role in developing capabilities within the workforce, simulation-based learning can evoke or replicate substantial aspects of the real world in a fully interactive fashion. This paper aims to present outcomes of simulation-based learning sessions the authors designed and delivered in a disaster risk management course.

The authors developed a framework to illustrate simulation-based learning in a disaster risk management programme. It was then used as a guide to design and execute simulation-based learning sessions. An autoethnographic methodology was then applied to reflectively narrate the experiences and feelings during the design and execution of the simulations.

The evaluation of the simulation sessions showed that participants were able to apply their knowledge and demonstrate the skills required to make critical decisions in disaster risk reduction. The conclusion from the simulation-based learning sessions is that making simulation-based learning a part of the pedagogy of disaster risk management education enables students to gain practical experience, deliberate ethical tensions and practical dilemmas and develop the ability to work with multiple perspectives.

The simulated workplace experience allowed students to experience decision-making as disaster risk management professionals, allowing them to integrate theory with practice.