THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Polyurethanes (PUs) are a class of versatile materials with great potential for use in different applications, especially based on their structure–property relationships. Their specific mechanical, physical, biological, and chemical properties are attracting significant research attention to tailoring PUs for use in different applications. Enhancement of the properties and performance of PU-based materials may be achieved through changes to the production process or the raw materials used in their fabrication or via the use of advanced characterization techniques. Clearly, modification of the raw materials and production process through proper methods can produce PUs that are suitable for varied specific applications. The present study aims to shed light on the chemistry, types, and synthesis of different kinds of PUs. Some of the important research studies relating to PUs, including their synthesis method, characterization techniques, and research findings, are comprehensively discussed. Herein, recent advances in new types of PUs and their synthesis for various applications are also presented. Furthermore, information is provided on the environmental friendliness of the PUs, with a specific emphasis on their recyclability and recoverability.

https://ir.unikl.edu.my/jspui/bitstream/123456789/15237/1/Polyurethane%20types%2c%20synthesis%20and%20applications%20%e2%80%93%20a%20review.pdf

Polyurethane types, synthesis and applications – a review

Renewable and sustainable biobased materials: An assessment on biofibers, biofilms, biopolymers and biocomposites

There has been a growing interest in utilizing fibers as reinforcement to produce composite materials. Scientists prefer thermoplastic polymeric matrices than thermosets due to the low production cycle, lower cost of processing and high reparability of thermoplastics. Fiber-reinforced thermoplastic matrix composites have gained commercial success in the semistructural and structural applications. Various fibers are widely used as reinforcement in thermoplastic polypropylene (PP) matrix to prepare composites. Mechanical properties of fiber-reinforced PP composites (FRPCs) are studied by many researchers and few of them are discussed in this article. Various fiber treatments, which are carried out to improve the fiber–matrix adhesion to get improved mechanical properties, are also discussed in this article. This article also focuses on coupling agents and fiber loading which affect the mechanical properties of FRPCs significantly.

Mechanical properties of polypropylene composites: A review

https://espace.library.uq.edu.au/view/UQ:08f48a6/UQ08f48a6_OA.pdf

Degradation and stabilization of polyurethane elastomers

Influence of hydration on the mechanical, structural, thermal, and morphological properties of cement filled epoxy composites

Glass fiber (GF) and hydroxyl‐functionalized multi‐walled carbon nanotubes (MWCNTs)‐reinforced polyester‐based composites were prepared by solution casting technique. Unsaturated polyester (UPE) was mixed separately with a fixed amount (0.5 wt%) of hydroxyl‐functionalized MWCNTs and GF (5.0 wt%). Multi‐walled carbon nanotubes (MWCNTs) were functionalized with hydroxyl functional group (OH) prior to the fabrication of the composites. The structural properties were evaluated by Fourier transform infrared spectroscopy. The mechanical properties of the composites, like tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength were also evaluated. The surface of the samples was observed by the field‐emission electron microscopy. In addition, the thermal stability was assessed by thermogravimetric analysis and differential scanning calorimetry. The dynamic thermal mechanical analysis was also performed to assess the performance of the composites at elevated temperature. A comparative analysis of the composites prepared with GF and hydroxyl‐functionalized MWCNTs was described. Result analysis showed that hydroxyl functional group‐based MWCNTs is more effective for improving the properties of the composites, compared to the others. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers

Thermo‐mechanical properties of glass fiber and functionalized multi‐walled carbon nanotubes filled polyester composites

The properties of biodegradability or non-biodegradability are highly important for the design and application of sustainable materials. The objective of this work is to introduce a novel type of nanocomposite comprising a natural fibre reinforcing agent impregnated with copper nanoparticles, and to control the biodegradability of this sustainable material using the function of the impregnated copper nanoparticles. At room temperature, copper nanoparticles were synthesized and impregnated into palm oil fibre to improve the strength and durability of the fibre and the material properties of the composite. Fourier transform infrared spectroscopic techniques were used to characterize the prepared composites. The biodegradability (minimum to maximum boundary) of the composite was studied (using the soil burial test) as a function of the quantity of copper nanoparticles, where the tensile strength was fixed at the maximum. The property of biodegradability was also optimized with the help of response surface methodology. The biodegradability of the developed composites ranged from 26.72 to 6.51% when the concentration of impregnated copper nanoparticles was varied from 0 to 2590 μg g−1 respectively. The results indicate that copper nanoparticles can be considered as a potential biocide in composite materials and in this work for controlling the biodegradability of the material by varying the quantity of impregnated copper. The relationship between the responses and variables selected in this study has been justified by the predicted models. Moreover, the model terms have been explained and the prediction has also been performed successfully. Thus, copper nanoparticles have been successfully applied for controlling the biodegradability of the nanocomposite materials. The prepared nanocomposite materials are considered for both indoor and outdoor applications. This study is quite promising for controlling the biodegradability of advanced materials, especially when the degree of biodegradability is so important for their respective applications.

Control of biodegradability in a natural fibre based nanocomposite as a function of impregnated copper nanoparticles

The aim of this research was to investigate the welding joint's fracture toughness and fracture surface morphologies between A7075-T651 aluminum and AZ31B magnesium dissimilar alloys welded using a new technique of gas metal arc spot lap welding with unconventional ER308L-Si stainless steel filler. The fracture toughness of the welding joints was estimated from yield strength and absorbed charpy impact energy of the joints using Rolfe–Novak–Barsom correlation, and was compared with the fracture toughness of AZ31B parent metal. Fracture surface morphologies were investigated by scanning electron microscopy. The results showed that the joint can achieve a maximum fracture toughness of 93.08% of the AZ31B parent metal. Most of the joints failed at AZ31B alloy, while some failed at A7075-T651 alloy and ER308L-Si nugget. Brittle fracture mechanism was observed for all the joints. It was found that the new gas metal arc spot lap welding technique with ER308L-Si filler could offer very good mechanical properties.

GMA Spot Welding of A7075-T651/AZ31B Dissimilar Alloys Using Stainless Steel Filler

Multi-walled carbon nanotube (MWCNT) reinforced polyester-based composites were prepared by mixed blending in a solvent. Orthophthalic unsaturated polyester was blended individually with different types of non-functionalized and functionalized MWCNTs. Two types of functional groups: hydroxyl (-OH) and carboxyl (-COOH) were introduced with MWCNTs for the nanocomposites. The mechanical properties of the composites, like tensile, three-point bending and impact energy were evaluated. Fourier transform infrared spectroscopy was used for the functional group analysis. The dispersion characteristics of the samples were observed by transmission electron microscopy and field-emission electron microscopy. In addition, the thermal decomposition and melting behavior of the samples was assessed by differential scanning calorimetry and thermogravimetric analysis. The properties were varied due to the variation of the functional groups. The result analysis showed that the entangled agglomerations of hydroxyl-functionalized MWCNTs were destroyed to relatively smaller clusters. The hydroxyl-functionalized MWCNTs were more effective for homogeneous dispersion and contributed for better mechanical properties of the composites, compared to non-functionalized and carboxyl group-functionalized MWCNTs.

Muhammad Remanul Islam

Papers

Influence of hydration on the mechanical, structural, thermal, and morphological properties of cement filled epoxy composites

Thermo‐mechanical properties of glass fiber and functionalized multi‐walled carbon nanotubes filled polyester composites

Control of biodegradability in a natural fibre based nanocomposite as a function of impregnated copper nanoparticles

GMA Spot Welding of A7075-T651/AZ31B Dissimilar Alloys Using Stainless Steel Filler

Dispersion characteristics of hydroxyl and carboxyl-functionalized multi-walled carbon nanotubes in polyester nanocomposites