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Article
Publication date: 1 June 2000

H.L. Manock

Waterborne polyurethane dispersions (PUDs) continue to show growth in commercial usage due to the ever increasing environmental legislation to reduce VOC in coating and…

Abstract

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.

Details

Pigment & Resin Technology, vol. 29 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 December 2004

X. Li, Z. Gao, J. Gu, F. Zhao and X. Bai

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…

Abstract

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.

Details

Pigment & Resin Technology, vol. 33 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 30 August 2013

Gururaj N. Manvi and Ramanand N. Jagtap

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Practical implications

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

Originality/value

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

Details

Pigment & Resin Technology, vol. 42 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 August 1955

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.

Abstract

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.

Details

Anti-Corrosion Methods and Materials, vol. 2 no. 8
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 13 August 2018

Jizhi Zhang and Xiankai Jiang

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Practical implications

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).

Originality/value

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.

Details

Pigment & Resin Technology, vol. 47 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 3 February 2021

Abbas Ahmad Adamu, Norazilawati Muhamad Sarih and Seng Neon Gan

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Research limitations/implications

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.

Practical implications

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.

Social implications

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.

Originality/value

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

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 December 1997

J.‐P. CIech

This paper presents a solder joint engineering reliability model —Solder Reliability Solutions** (SRS) — and its application to surface mountarea‐array and chip‐scale…

Abstract

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.

Details

Soldering & Surface Mount Technology, vol. 9 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 17 April 2007

Michael Osterman and Michael Pecht

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Research limitations/implications

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.

Originality/value

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.

Details

Soldering & Surface Mount Technology, vol. 19 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 December 2002

P. Towashiraporn, G. Subbarayan, B. McIlvanie, B.C. Hunter, D. Love and B. Sullivan

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…

Abstract

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.

Details

Soldering & Surface Mount Technology, vol. 14 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

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