一二三四区视频,亚洲少妇熟女色,日本久热无码视频网,欧美国产日韩大尺度,亚洲a视频,久久少妇一区二区,日韩999无码视频,刺激久久久久久久,啊啊啊啊不要啊在线

ChemicalBook >> journal list >> Advanced Materials Research >>article

Advanced Materials Research

Download PDF

Synthesis and Properties of a High-Molecular-Weight Polyimide Based on 4, 4'-(hexafluoroisopropylidene) Diphthalic Anhydride

Published:1 July 2012 DOI: 10.4028/www.scientific.net/AMR.550-553.742
Hui Wu,?Hua Li,?Hezhou Liu

Abstract

A soluble polyimide with high molecular weight was synthesized from 4, 4'-(hexafluoroiso propylidene) diphthalic anhydride (6FDA) and 2, 2’-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (BAPAF) via two-step polycondesation procedure involving the preparation of poly(amic acid) (PAA) followed by chemical imidization. Effect of synthesis parameters on polyimide molecular weight involving material ratio, imidization temperature and imidization catalyst were studied. Synthesized PI was analyzed with respect to their molecular weights, chemical structures and solubility through GPC, FTIR, XRD and solubility tests respectively. The results showed that a high-molecular-weight PI was successfully synthesized from 4, 4'-(hexafluoroisopropylidene) diphthalic anhydride and 2, 2’-bis (3-amino-4-hydroxyphenyl) hexafluoropropane with imidization at 80°C for 3h, material ratio of n(BAPAF):n(6FDA) equal to 1:1 and catalyst of n(triethylamine):n (pyridine) less than1:3. The obtained PI showed excellent solubility in polar aprotic organic solvents such as NMP, DMAc, DMSO, THF and Acetone. Poly(6FDA-BAPAF) PI, with high molecular weight and excellent solubility, which was synthesized under lower imidization temperature that was equal to 80°C,could be easily obtained and convenient to process, thus it is a potential material for membrane separation.

Substances (6)

Related products
Procduct Name CAS Molecular Formula Supplier Price
Dimethyl sulfoxide 67-68-5 C2H6OS 1924 suppliers $5.00-$120900.00
N-Methyl-2-pyrrolidone 872-50-4 C5H9NO 1185 suppliers $6.35-$15500.00
Tetrahydrofuran 109-99-9 C4H8O 1168 suppliers $9.00-$17160.00
N,N-Dimethylacetamide 127-19-5 C4H9NO 1055 suppliers $5.00-$8680.00
4,4'-(Hexafluoroisopropylidene)diphthalic anhydride 1107-00-2 C19H6F6O6 483 suppliers $6.00-$1996.09
2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane 83558-87-6 C15H12F6N2O2 422 suppliers $8.00-$1765.04

Similar articles

IF:5.1

Porogenic Solvents Influence on Morphology of 4-Vinylbenzyl Chloride Based PolyHIPEs

Macromolecules Karel Je?ábek*, Irena Pulko,etc Published: 3 May 2008
IF:2.7

Penetration of different molecular weight hydrolysed keratins into hair fibres and their effects on the physical properties of textured hair

International Journal of Cosmetic Science E. Malinauskyte, R. Shrestha,etc Published: 18 September 2020
潮州市| 沧州市| 陇南市| 宝山区| 锦州市| 二手房| 肃南| 苍山县| 建阳市| 拉萨市| 长顺县| 宣化县| 寻乌县| 区。| 宽城| 图片| 长阳| 霍州市| 建阳市| 东台市| 杭州市| 海城市| 青铜峡市| 虎林市| 农安县| 利辛县| 开原市| 九龙城区| 台安县| 桃源县| 梅河口市| 崇信县| 石首市| 天门市| 大关县| 通州市| 织金县| 鄂托克前旗| 哈尔滨市| 商水县| 县级市|