Development of Some Promising Approaches for The Toughening of High-Temperature Polymers

1998 ◽  
Vol 519 ◽  
Author(s):  
C. Kumudinie ◽  
J. K. Premachandra ◽  
J. E. Mark ◽  
T. D. Dang ◽  
M. R. Unroe ◽  
...  

AbstractHigh-temperature poly(arylene ether) and hydroxypolybenzoxazole polymers were toughened using dispersed rubbery phases. This rubbery phase was a hybrid material which was in-situ generated within the polymer matrix using mixtures of partially-hydrolyzable trialkoxy and dialkoxy organosilanes with a fully hydrolyzable tetraalkoxysilane. The resulting materials were characterized with regard to their structures, mechanical properties (modulus, ultimate strength, maximum extensibility, and toughness), thermal properties, optical properties, and tendencies to absorb water. Some of the results are presented here.

2014 ◽  
Vol 1015 ◽  
pp. 381-384
Author(s):  
Li Liu ◽  
Li Hai Cai ◽  
Dan Liu ◽  
Jun Xu ◽  
Bao Hua Guo

The poly (butylene succinate) (PBS) and 3 wt% attapulgite (ATP) reinforced PBS/ATP nanocomposites with 1,6-hexanediol were fabricated using an in situ polymerization method. The crystallization behaviors indicated that ATP had effectively acted as nucleating agent, resulting in the enhancement on the crystallization temperature. The SEM results showed a superior interfacial linkage between ATP and PBS. Also, ATP could disperse as a single fiber and embed in the polymer matrix, which resulted in the improved mechanical properties.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1403 ◽  
Author(s):  
Lifen Tong ◽  
Xiting Lei ◽  
Guangyao Yang ◽  
Xiaobo Liu

A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN–OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN–OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN–OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 °C to 203.6 °C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN–OH films. Moreover, because of the excellent adhesive property of PEN–OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN–OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN–OH has potential applications in the electronic field.


2014 ◽  
Vol 900 ◽  
pp. 141-145 ◽  
Author(s):  
Can Feng Fang ◽  
Guang Xu Liu ◽  
Ling Gang Meng ◽  
Xing Guo Zhang

The effects of in-situ TiB2 particle fabricated from Al-Ti-B system via the self-propagating high-temperature synthesis (SHS) reaction technology on microstructure and mechanical properties of Mg-Sn-Zn-Al alloy were investigated. The results indicate that the size of the Mg2Sn and α-Mg+Mg32(Al,Zn)49 phase becomes coarser with the increasing content of Al-Ti-B preform, meanwhile the amount of eutectic α-Mg+Mg32(Al,Zn)49 phase increases too. The addition of Al-Ti-B is favorable toward promoting the strength of composites, but deteriorates elongation. The resulting as-extruded composite material with 4 wt.% Al-Ti-B preform exhibits good overall mechanical properties with an ultimate tensile strength of 291 MPa and an elongation over 2 %.


2021 ◽  
Author(s):  
Matthias Schwartzkopf ◽  
Sven-Jannik Wöhnert ◽  
Vivian Waclawek ◽  
Niko Carstens ◽  
André Rothkirch ◽  
...  

At the nascence of a metal–polymer hybrid material primarily vertical Au dimers and free adatoms diffuse on and into the polymer matrix revealed in situ by sub-millisecond time-resolved surface-sensitive X-ray scattering (GISAXS).


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 629
Author(s):  
Anagh Deshpande ◽  
Subrata Deb Nath ◽  
Sundar Atre ◽  
Keng Hsu

Selective laser melting (SLM) is one of the most widely used additive manufacturing technologies. Fabricating nickel-based superalloys with SLM has garnered significant interest from the industry and the research community alike due to the excellent high temperature properties and thermal stability exhibited by the alloys. Haynes-282 alloy, a γ′-phase strengthened Ni-based superalloy, has shown good high temperature mechanical properties comparable to alloys like R-41, Waspaloy, and 263 alloy but with better fabricability. A study and comparison of the effect of different heat-treatment routes on microstructure and mechanical property evolution of Haynes-282 fabricated with SLM is lacking in the literature. Hence, in this manuscript, a thorough investigation of microstructure and mechanical properties after a three-step heat treatment and hot isostatic pressing (HIP) has been conducted. In-situ heat-treatment experiments were conducted in a transmission electron microscopy (TEM) to study γ′ precipitate evolution. γ′ precipitation was found to start at 950 °C during in-situ heat-treatment. Insights from the in-situ heat-treatment were used to decide the aging heat-treatment for the alloy. The three-step heat-treatment was found to increase yield strength (YS) and ultimate tensile strength (UTS). HIP process enabled γ′ precipitation and recrystallization of grains of the as-printed samples in one single step.


1994 ◽  
Vol 374 ◽  
Author(s):  
Daniel J. Sandman ◽  
Jeffrey L. Conroy ◽  
Joseph Piche

AbstractIn the interest of finding useful materials systems for optical limiting, we have sought to combine the attractive third order nonlinear optical properties of polydiacetylenes (PDA) with the desirable ballistic and mechanical properties of polycarbonates in our study of two different systems. Composites of Lexan polycarbonate with the PDA from 1,6-di-N-carbazolyl-2,4-hexadiyne have attractive laser power transmission characteristics. Macromonomers derived from the chloroformates of bis -phenols A and F and diacetylene diols were synthesized, their spectral, molecular weight, and thermal properties were studied, and the crosslinking of the macromonomers to PDA structures was investigated.


2017 ◽  
Vol 23 (S1) ◽  
pp. 782-783
Author(s):  
Sanjit Bhowmick ◽  
Chandra Sekhar Tiwary ◽  
S. A. Syed Asif ◽  
Pulickel M. Ajayan

2012 ◽  
Vol 479-481 ◽  
pp. 395-398
Author(s):  
Dan Qing Chen

This document explains and demonstrates how to prepare Polyurethane(PU)/Expanded Graphite powder(EGp) composite antistatic sponge by in situ polymerization. The morphology、mechanical、electrical and thermal properties of the PU/EGp composite antistatic sponge have been investigated. PU/ EGp composite sponge have better mechanical properties than that of CB composite. The resistivity of PU/EGp composite antistatic sponge can reach at about 108Ω•cm at the content around 5wt% of the EGp. EGp can stably exist in PU sponge and has little influence to the polymeric matrix while being heated.


2011 ◽  
Vol 295-297 ◽  
pp. 161-164 ◽  
Author(s):  
Xin Hong Liu ◽  
En Xia Xu ◽  
Chao Jie Zhou

The composite specimens have been prepared using fused corundum, silicon and bauxite-based β-SiAlON powder as starting materials. The physical properties, high temperature modulus of rupture (HMOR), thermal shock resistance (TSR), phase composition and microstructure of the specimens after firing at 1500°C have been studied. The results show: (1) Al2O3-SiC-SiAlON composites are sintered well at 1500°C. (2) HMOR and TSR of the specimens increase with increase of Si content, high temperature properties are further increased with appropriate β-SiAlON addition. (3) The in-situ formed SiC and O’-SiAlON fill in the interstices of corundum skeleton structure, forming interlocking network structure, thus creating strengthening and toughening effects.


Sign in / Sign up

Export Citation Format

Share Document