scholarly journals Expanding Monomers as Anti-Shrinkage Additives

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 806
Author(s):  
Philipp Marx ◽  
Frank Wiesbrock
Keyword(s):  
Ring Opening ◽  
Covalent Bond ◽  
Volumetric Shrinkage ◽  
Structure Property ◽  
Atomic Packing ◽  
Materials Properties ◽  
Volumetric Expansion ◽  
Structure Property Relationships ◽  
Ring Opening Reaction ◽  
Measuring Techniques

Commonly, volumetric shrinkage occurs during polymerizations due to the shortening of the equilibrium Van der Waals distance of two molecules to the length of a (significantly shorter) covalent bond. This volumetric shrinkage can have severe influence on the materials’ properties. One strategy to overcome this volumetric shrinkage is the use of expanding monomers that show volumetric expansion during polymerization reactions. Such monomers exhibit cyclic or even oligocyclic structural motifs with a correspondingly dense atomic packing. During the ring-opening reaction of such monomers, linear structures with atomic packing of lower density are formed, which results in volumetric expansion or at least reduced volumetric shrinkage. This review provides a concise overview of expanding monomers with a focus on the elucidation of structure-property relationships. Preceded by a brief introduction of measuring techniques for the quantification of volumetric changes, the most prominent classes of expanding monomers will be presented and discussed, namely cycloalkanes and cycloalkenes, oxacycles, benzoxazines, as well as thiocyclic compounds. Spiroorthoesters, spiroorthocarbonates, cyclic carbonates, and benzoxazines are particularly highlighted.

Why is the Japanese Sword Curved ?

1990 ◽  
Vol 185 ◽  
Author(s):  
William N. Weins ◽  
Peter Bleed
Keyword(s):  
Residual Stresses ◽  
Cutting Edge ◽  
16Th Century ◽  
Strain Gages ◽  
Structure Property ◽  
Volumetric Expansion ◽  
Structure Property Relationships ◽  
Compressive Stresses ◽  
Residual Compression

AbstractThe history and methodology of Japanese swordmaking are reviewed with particular reference to materials and processes. In order to gain a better understanding of the structure/property relationships in Japanese swords, a 16th century katana was analyzed metallographically and by attaching strain gages and cutting to relieve the residual stresses in the blade. The results indicate that the curve in the blade can be attributed to the volumetric expansion of the untempered martensite on the cutting edge, which also causes the edge to be in a state of residual compression. The residual compressive stresses are one of the key elements of the Japanese sword which give it superior toughness and cutting ability.

A Comparative Study of the Structure/Property Relationships of Langmuir-Blodgett and Spin-Cast Films of an Amphiphilic, Regioregular Polythiophene Polymer

2006 ◽  
Vol 949 ◽  
Author(s):  
Jusroop Mattu ◽  
Thomas Johansson ◽  
Steven Holdcroft ◽  
Gary W. Leach
Keyword(s):  
Thin Films ◽  
Comparative Study ◽  
Conjugated Polymer ◽  
Structure Property ◽  
Materials Properties ◽  
Langmuir Blodgett ◽  
Thermal Reactivity ◽  
Structure Property Relationships ◽  
Structural Conformation ◽  
Cast Films

ABSTRACTThe effects of structural conformation and order on materials properties and reactivity in thin films of an amphiphilic, regioregular polythiophene π-conjugated polymer (πCP) derivative are presented. Thin films deposited by the Langmuir Blodgett technique provide highly ordered anisotropic films compared to those deposited by spin cast methods. Large differences in both the thermal reactivity and physical properties of the films are observed.

Syntheses of 6-O-ethyl/methyl-celluloses via ring-opening copolymerization of 3-O-benzyl-6-O-ethyl/methyl-α-d-glucopyranose 1,2,4-orthopivalates and their structure–property relationships

Cellulose ◽  
2009 ◽  
Vol 16 (6) ◽  
pp. 1179-1185 ◽  
Author(s):  
Hiroshi Kamitakahara ◽  
Toshihiro Funakoshi ◽  
Shinji Nakai ◽  
Toshiyuki Takano ◽  
Fumiaki Nakatsubo
Keyword(s):  
Ring Opening ◽  
Structure Property ◽  
Ethyl Methyl ◽  
Structure Property Relationships

Structure property relationships in linear and cross-linked poly(imidonorbornenes) prepared using ring opening metathesis polymerisation (ROMP)

Polymer ◽  
2001 ◽  
Vol 42 (23) ◽  
pp. 9413-9422 ◽  
Author(s):  
P.J Hine ◽  
T Leejarkpai ◽  
E Khosravi ◽  
R.A Duckett ◽  
W.J Feast
Keyword(s):  
Ring Opening ◽  
Structure Property ◽  
Structure Property Relationships

Synthesis and properties of polyimides from 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl

2012 ◽  
Vol 24 (8) ◽  
pp. 783-792 ◽  
Author(s):  
Atsushi Morikawa ◽  
Fumi Miyata ◽  
Jun Nishimura
Keyword(s):  
Ring Opening ◽  
Mechanical Analysis ◽  
Ring Opening Polymerization ◽  
Dielectric Constants ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Property Relationships ◽  
Step Procedure

Diamines, namely, 1,4-bis(4-amino-2-phenylphenoxy) benzene (1) and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl (2), were synthesized from 4-fluoro-3-phenyl nitrobenzene. Two series of polyimides were synthesized from these diamines with nine types of dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. The polyimides were characterized by x-ray diffraction, differential scanning calorimetry, thermogravimetry and dynamic mechanical analysis. The polyimides from 1 and 2 had a glass transition temperature in the range of 221–254°C and 222–271°C, respectively, and all the polymers were amorphous. The structure–property relationships of these polyimides were examined and compared with those of the previously prepared analogous polyimides from the bis(4-amino-2-biphenyl)ether (3). Water absorption and dielectric constants ( ∊) of the polyimides were compared and discussed on the basis of imide content per repeating unit.

The Structural Studies of Oxirane Ring Opening Reaction in Epoxidized Natural Rubber (ENR-50) by SnCl2.2H2O and the Formation of ENR/TiN Complex Hybrid

2012 ◽  
Vol 626 ◽  
pp. 727-737
Author(s):  
Hamzah Rosniza ◽  
Abu Bakar Mohamad
Keyword(s):  
Natural Rubber ◽  
Ring Opening ◽  
Covalent Bond ◽  
Methine Proton ◽  
Oxirane Ring ◽  
Epoxidized Natural Rubber ◽  
H Nmr ◽  
Ring Opening Reaction ◽  
Complex Hybrid ◽  
C Nmr

Oxirane ring opening reaction of epoxidized natural rubber (ENR-50) is a promising method to produce hybrids or introduce reactive fillers into the polymers through the covalent bond. This paper reports the reaction between ENR-50 and SnCl2.2H2O under CO2environment. The complex formation is characterized via FTIR,1H,13C and119Sn NMR.1H NMR which displays deduction of methine proton integrals at δ 2.71 ppm implies the occurrence ring opening reaction. While13C NMR reveals new peaks which corresponds to Sn-C bond. The119Sn NMR proves four-coordinates tin in ENR/Sn complex hybrid.

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