1-20 of 20 Search Results for

Depolymerization

Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003013
EISBN: 978-1-62708-200-6
... polymers that decompose mechanistically by unzipping the polymer chains to give monomers in high yields. Other polymers produce mixtures of liquid or gaseous products when pyrolyzed. Decomposition of polymer to monomer is referred to as thermal depolymerization, and decomposition of polymer to liquids...
Series: ASM Handbook
Volume: 5B
Publisher: ASM International
Published: 30 September 2015
DOI: 10.31399/asm.hb.v05b.a0006073
EISBN: 978-1-62708-172-6
... to continue growth. Free radical reactions result in chain scission (breaking of the molecular chain); depolymerization (reducing a polymeric chain to its monomer units); branching (a short growth at a free radical site); self cyclicization (forming a circular molecule by joining with another portion...
Series: ASM Handbook
Volume: 13B
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v13b.a0003844
EISBN: 978-1-62708-183-2
...), depolymerization (reducing a polymeric chain to its monomer units), branching (a short growth at a free-radical site), self cyclization (forming a circular molecule by joining with another portion of the backbone of a molecule), and the formation of double bonds. All of these free-radical reactions, which...
Book Chapter

Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003014
EISBN: 978-1-62708-200-6
..., Overheating may cause explosive depolymerization G, Overheating may cause premature curing of (thermoset) compound H, Venting is recommended to remove volatiles and reduce splay I, Fiber reinforcement lengths may be severely reduced J, Overheating may produce chemical changes in the base polymer...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003028
EISBN: 978-1-62708-200-6
..., such as poly-α-methylstyrene, and polymers that can release small molecules, such as PVC, polyacrylonitrile (PAN), and polyisobutylene (PIB), undergo thermal degradation at relatively low temperatures via unzipping. When heated at 270 °C (520 °F), polymethyl methacrylate (PMMA) depolymerizes, producing methyl...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004032
EISBN: 978-1-62708-185-6
... is depolymerized, and is made more ionic and also much less viscous, by the incorporation of network modifiers such as Na 2 O, K 2 O, Li 2 O, CaO, and MgO. Some oxides, primarily Al 2 O 3 and, to a lesser extent, PbO, act as both network formers and modifiers. However, PbO is toxic and contaminates waste waters...
Book Chapter

By Tim Pepper
Series: ASM Handbook
Volume: 21
Publisher: ASM International
Published: 01 January 2001
DOI: 10.31399/asm.hb.v21.a0003363
EISBN: 978-1-62708-195-5
... polymers and is caused by their depolymerization to form monomeric species. Among polyesters, high-molecular-weight UPEs and epoxy vinyl esters show better stability above 150 °C (302 °F) than low-molecular- weight UPEs. High-molecular-weight isophthalic, PET, DCPD, and BPA fumarate resins, when...
Series: ASM Handbook
Volume: 23
Publisher: ASM International
Published: 01 June 2012
DOI: 10.31399/asm.hb.v23.a0005676
EISBN: 978-1-62708-198-6
... properties Physical Sorption Swelling Softening Dissolution Mineralization Extraction Crystallization Decrystallization Stress cracking Fatigue fracture Impact fracture Chemical Thermolysis  Radical scission Depolymerization Oxidation  Chemical...
Series: ASM Handbook
Volume: 20
Publisher: ASM International
Published: 01 January 1997
DOI: 10.31399/asm.hb.v20.a0002464
EISBN: 978-1-62708-194-8
Book Chapter

Series: ASM Handbook
Volume: 21
Publisher: ASM International
Published: 01 January 2001
DOI: 10.31399/asm.hb.v21.a0003370
EISBN: 978-1-62708-195-5
... to prevent molecular weight attrition. (d) Drying may volatilize monomers essential to the curing reaction. (e) Fiber reinforcement breakage may occur during force feeding. (f) Overheating may cause explosive depolymerization. (g) Overheating may cause premature curing of (thermoset) compound...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003006
EISBN: 978-1-62708-200-6
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003053
EISBN: 978-1-62708-200-6
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003255
EISBN: 978-1-62708-176-4
... polymers, thermosets do not have real glass-transition temperatures and thus will not melt during heating. Instead, they tend to degrade (depolymerize) at elevated temperatures. Fig. 15 Schematic representation of the structure of a phenol formaldehyde. (a) Two phenol rings join with a formaldehyde...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003023
EISBN: 978-1-62708-200-6
Series: ASM Handbook
Volume: 14B
Publisher: ASM International
Published: 01 January 2006
DOI: 10.31399/asm.hb.v14b.a0005159
EISBN: 978-1-62708-186-3
... in a wide range of viscosities by controlling molecular weight. They have a unique property of depolymerizing at high temperatures. This makes them useful as rolling and drawing oils for ferrous and nonferrous forming operations where subsequent annealing would produce staining if petroleum oil forming...
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003256
EISBN: 978-1-62708-176-4
... (network) resins (which are cured resins with cross links that depolymerize upon exposure to elevated temperatures above T g ). Typical mechanical properties of various thermoplastic and thermoset resins are briefly summarized in Tables 4 and 5 . Engineering plastics are not as strong as metals...
Book Chapter

Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003065
EISBN: 978-1-62708-200-6
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003008
EISBN: 978-1-62708-200-6
... as the temperature increases. Above 290 °C (550 °F), ABS decomposes by means of depolymerization and oxidation reactions and is then generally unsuitable for processing. Typical bulk density values of ABS pellets are 610 to 700 g/cm 3 . Regrind materials range from 500 to 610 g/cm 3 in bulk density...
Series: ASM Handbook
Volume: 7
Publisher: ASM International
Published: 30 September 2015
DOI: 10.31399/asm.hb.v07.a0006141
EISBN: 978-1-62708-175-7
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003009
EISBN: 978-1-62708-200-6
... 90% crystalline before molding. It will withstand continuous exposure to a temperature near absolute zero (−273 °C, or −459 °F) without reaction. The polymer has an initial melting point of 342 °C (648 °F), and although it does not char, it does begin to depolymerize at about 600 °C (1112 °F...