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molecular composition

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Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2007
DOI: 10.31399/asm.tb.smnm.t52140005
EISBN: 978-1-62708-264-8
... the freezing temperature line maps out all possible temperature-composition coordinates that are found to be liquid. Notice that at the extreme left of the diagram there is a thin shaded region labeled “Solid ice.” This solid ice has the same molecular structure as pure water ice, but now it contains a very...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780105
EISBN: 978-1-62708-281-5
... in characterizing thermoplastics, whether they are homogeneous resins, alloyed or blended compositions, or highly modified thermoplastic composites. The information herein is applicable to all these major resin groupings; no attempt has been made to contrast one against another. Molecular Weight Determination...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.scm.t52870063
EISBN: 978-1-62708-314-0
... matrices for advanced composites are classified as either thermosets or thermoplastics. Thermosets are low molecular weight, low viscosity monomers (≈2000 centipoise) that are converted during curing into three-dimensional crosslinked structures that are infusible and insoluble. Crosslinking ( Fig. 3.1...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.omfrc.t53030237
EISBN: 978-1-62708-349-2
.... The change in the molecular composition may extend only a few nanometers on the surface but can continue to progress into the bulk of the composite matrix. Composite materials having polymeric matrices are susceptible to degradation from heat, sunlight, ozone, atomic oxygen (in space), moisture, solvents...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780359
EISBN: 978-1-62708-281-5
..., plasticizers, colorants, antidegradants, and process aids. It is this combination of molecular structure and complex formulation that requires specialized testing ( Ref 2 ). While the chemical composition of a failed metal component can often be evaluated using a single spectroscopic technique, a similar...
Image
Published: 01 November 2010
Fig. 10.2 Micrograph of a carbon fiber composite material that was toughened using two rubber materials of different molecular weight. Two different phase morphologies are observed, corresponding to the different tougheners. Ultrathin section. Transmitted light, Hoffman modulation contrast, 40 More
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780343
EISBN: 978-1-62708-281-5
... to determine the glass transition region, relaxation spectra, degree of crystallinity, molecular orientation, cross linking, phase separation, structural or morphological changes resulting from processing, and chemical composition in polymer blends, graft polymers, and copolymers.” Polymer composites have also...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.omfrc.t53030177
EISBN: 978-1-62708-349-2
.... 10.2 Micrograph of a carbon fiber composite material that was toughened using two rubber materials of different molecular weight. Two different phase morphologies are observed, corresponding to the different tougheners. Ultrathin section. Transmitted light, Hoffman modulation contrast, 40× objective...
Series: ASM Technical Books
Publisher: ASM International
Published: 30 April 2021
DOI: 10.31399/asm.tb.tpsfwea.t59300301
EISBN: 978-1-62708-323-2
... Abstract This chapter covers the friction and wear behaviors of plastics and elastomers. It begins by describing the molecular differences between the two types of polymers and their typical uses. It then discusses the important attributes of engineering plastics and their suitability...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780003
EISBN: 978-1-62708-281-5
... be calculated in several different ways (see the next article “ Effects of Composition, Processing, and Structure on Properties of Engineering Plastics ” in this book). Molecular weight and molecular-weight distribution are useful in characterizing the properties of plastic. For any given polymer, the lower...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780115
EISBN: 978-1-62708-281-5
... oxygen-methylene isomorphism, the effect of composition on T g is minimal ( Ref 6 , 7 ). Variation with Molecular Weight The T g has been shown to increase with the molecular weight of the polymer until a limiting value in T g is achieved ( Ref 8 ). The Fox-Flory equation: (Eq 1...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780089
EISBN: 978-1-62708-281-5
... Abstract This article focuses on characterization techniques used for analyzing the physical behavior and chemical composition of thermoset resins, namely chromatography and infrared spectroscopy. The main purpose is to give sufficient detail to permit the reader understand a particular test...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.scm.t52870401
EISBN: 978-1-62708-314-0
..., paint systems are useful in protecting composite structures from ultraviolet (UV) radiation. Ultraviolet radiation is the band of light from 300 to about 4000 Å. It can cause degradation through molecular weight change and crosslinking in the resin system. However, this damage is generally limited...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 30 April 2020
DOI: 10.31399/asm.tb.bpapp.t59290035
EISBN: 978-1-62708-319-5
... components produced with binder assistance, the binder is removed prior to sintering. Some examples of engineering components where the binder remains in the final product are bonded magnets, tungsten-polymer composites for radiation shields, and metal-polymer composites for fishing lures. In binder...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.scm.t52870031
EISBN: 978-1-62708-314-0
... as physical and mechanical property data for commercially important high-strength fibers. aramid fibers carbon fibers composite reinforcement glass fibers graphite fibers prepreg ultra-high molecular weight polyethylene fibers woven fabrics REINFORCEMENTS for composite materials can...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 October 2012
DOI: 10.31399/asm.tb.lmub.t53550325
EISBN: 978-1-62708-307-2
... strength, and elongation. Plasticizers lower melt viscosity and processing temperature. Fundamentally, they function by broadening the molecular weight distribution and increasing the low-molecular-weight fraction of the total composition. Plasticizers are essentially nonvolatile solvents. 7.6 Effect...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780267
EISBN: 978-1-62708-281-5
... in the beginning but drops to a lower value after some sliding. Because of the presence of frictional stress and heat, the PTFE molecular chains are oriented in the direction of sliding, and a transfer film is deposited onto the counterface. The molecular orientation in PTFE is responsible for the drop in friction...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780146
EISBN: 978-1-62708-281-5
.... These chemical alterations of the molecular structure are not necessarily irreversible, as the effects can be reversed if the chemical is removed from the material (for example, by evaporation). Environmental stress cracking also can occur without significant absorption of an environmental reagent by the polymer...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2012
DOI: 10.31399/asm.tb.ffub.t53610327
EISBN: 978-1-62708-303-4
... Abstract This chapter covers the fatigue and fracture behaviors of ceramics and polymers. It discusses the benefits of transformation toughening, the use of ceramic-matrix composites, fracture mechanisms, and the relationship between fatigue and subcritical crack growth. In regard to polymers...
Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2010
DOI: 10.31399/asm.tb.omfrc.t53030001
EISBN: 978-1-62708-349-2
... decomposition temperature ( Ref 2 ). In contrast, thermoplastics, which consist of high-molecular-weight linear or branched polymer chains (not crosslinked), can be reshaped with the application of heat and pressure ( Ref 2 ). In relation to composite materials, the distinction between these types of matrices...