Compared with PI-1 derived from 1,3,4-APB/3,4'-ODA(75/25), BPDA and 4-PEA, PI-5(1,3,4-APB/3,4'-ODA(50/50)-BPDA-4PEA) shows improved meltability with minimum melt viscosity of 0.
A series of polyimide oligomers endcapped with 4-phenylethynylaniline have been prepared using the chemical compositions as shown in Table 1, in which PI-1 to PI-4 were prepared by the reaction of a diamine mixture of 1,3,4-APB and 3,4'-ODA at mole ratio of 75:25 with four different aromatic anhydrides including ODPA, BPDA, 6FDA, and 9FDA, respectively.
2] program was used In modeling studies to compare the energy levels of two model compounds derived from isomeric BPDA (16).
A series of homopolyimides and copolyimides was prepared by a condensation reaction between isomeric BPDA and several diamines followed by chemical imidization.
It was found that chain rigidity is a more critical factor to control CTE than the chain order for polyimides prepared from PMDA, BPDA
, and BTDA (3, 3',4,4'-benzophenone tetracarboxylic dianhydride) with PDA.
It shows that polymers containing PMDA and BPDA
were insoluble at room temperature or partially soluble upon heating.
Barg said the BPDA
is an exciting opportunity to set a precedent for more sophisticated developments in Bellingham.
Sample Feed BPDA Measured [eta] COOH contents Dielhylene contents BPDA ([g.
Accordingly, in our case, PETBB with 5-25 mol% of BPDA unit should display the crystalline nature of PET.
NOMENCLATURE BE Binding energy BPDA
Biphenyltetracarboxylic dianhydride CNT Carbon nanotube CTE Coefficient of thermal expansion DFT Density functional theory DMTA Dynamic mechanical thermal analysis EG Expanded graphite FGS Functionalized graphene sheets GO Graphene oxide MWCNT Multi-walled carbon nanotube NMP N-methyl-2-pyrrolidinone PAA Poly(amic acid) PDA Phenylene diamine P1 Polyimide PMMA Poly(methylmethacrylate) POSS Polyhedral oligomeric silsesquioxanes SSNMR Solid state nuclear magnetic resonance TMA Thermornechanical analysis TMS Tetramethylsilane XPS X-ray photoelectron spectroscopy XRD X-ray diffraction
Last month, the BPDA board of directors outlined for the first time a strategic plan for undertaking the daunting task of improving all five properties, which are all in various stages of development.
The purpose of this [strategic plan] is to evaluate the properties that are to be transferred to the public development authority," said BPDA Executive Director James Long.