Miscibiuty in Blends of Polybenzimidazole and Fluorine Containing Polyimides

1989 ◽  
Vol 171 ◽  
Author(s):  
Hiroaki Yamaoka ◽  
Norman E. Aubrey ◽  
William J. MAcknight ◽  
Frank E. Karasz

ABSTRACTBlends of polybenzimidazole (PBI) with either of two fluorine-containing polyimides were prepared by casting from solution and by precipitation. Dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) were used to study miscibility in the two blend systems.The blends of PBI with the first polyimide, the polysulfonimide Pl-1, consisted of a single phase when the blends contained less than 30 wt% Pl-1; above 50 wt% Pl-1, phase separation occurred even at room temperature. The PBI blends containing the second polyimide, Pl-2, were immiscible.

2019 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Takanori Fukami ◽  
Shuta Tahara ◽  
Arbi Dimyati

Manganese L-tartrate dihydrate, L-MnC4H4O6·2H2O, and manganese DL-tartrate dihydrate, DL-MnC4H4O6·2H2O, crystals were grown at room temperature by the gel method using silica gels as the growth medium. Differential scanning calorimetry, thermogravimetric-differential thermal analysis, and X-ray diffraction measurements were performed on both crystals. The space group symmetries (monoclinic P21 and P2/c) and structural parameters of the crystals were determined at room temperature. Both structures consisted of slightly distorted MnO6 octahedra, C4H4O6 and H2O molecules, and O–H···O hydrogen-bonding frameworks between adjacent molecules. Weight losses due to thermal decomposition of the crystals were found to occur in the temperature range of 300–1150 K. We inferred that the weight losses were caused by the evaporation of bound 2H2O molecules, and the evolutions of gases from C4H4O4 and of (1/2)O2 gas from MnO2, and that the residual black substance left in the vessels after decomposition was manganese oxide (MnO).


CORD ◽  
2013 ◽  
Vol 29 (1) ◽  
pp. 9
Author(s):  
I.D.K. Anom

Thermal and microstructure analysis of cocofoam made from vulcanized coconut fiber and latex compound were conducted. The cocofoam was produced by blending coconut fiber and latex compound with weight ratio of 10/25 (CF5-1) and 20/55 (CF5-2) at room temperature. The cocofoam characters were then analyzed by Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DTA) instruments. The result showed that the increase of coconut fiber and latex compound ratio produced a higher density of cocofoam. The highest value density was 0.6920 g/cm3 with flexibility of 90% produced by the CF5-2 sample. The SEM analysis showed that both specimens surface of the CF5-1 and CF5-2 samples have different pores size and the latex compound is not distributed thoroughly in the cocofoam. The thermal analysis showed that the production of cocofoam was largely determined by latex compound that served as fiber binder matrix. Cocofoam started to degrade at the temperature of 90oC and was damaged when it was heated at the temperature of 115oC for 2.5 hours.


1994 ◽  
Vol 6 (1) ◽  
pp. 35-41
Author(s):  
P N Prestont ◽  
V K Shaht ◽  
S W Simpsont ◽  
I Soutar ◽  
N J Stewart

New bismaleimides have been synthesised from diamines derived from benzophenone, 1,2-diphenylethane, 1,4-diphenylbutane, 2, 3-diphenylquinoxaline and 2, 3-diphenylnaphtho[2, 3-b]pyrazine. Cure profiles have been established by both differential scanning calorimetry (Dsc) and dynamic mechanical thermal analysis (DMTA). Cured resins prepared from the bismaleimide monomers were studied by thermal gravimetric analysis (TGA) with all materials exhibiting good thermal and thermo-oxidative stability.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2016
Author(s):  
Honghua Wang ◽  
Qilin Mei ◽  
Yujie Ding ◽  
Zhixiong Huang ◽  
Minxian Shi

Diallyl orthophthalate (DAOP) prepolymer was investigated as a reactive plasticizer to improve the processability of thermoplastics. The rheology of blends of DAOP prepolymer initiated by 2,3-dimethyl-2,3-diphenylbutane (DMDPB) and polyphenylene oxide (PPO) was monitored during the curing process, and their thermal properties and morphology in separated phases were also studied. Differential scanning calorimetry (DSC) results showed that the cure degree of the reactively plasticized DAOP prepolymer was reduced with increasing PPO due to the dilution effect. The increasing amount of the DAOP prepolymer led to a gradual decrease in the viscosity of the blends and the rheology behavior was consistent with the chemical gelation of DAOP prepolymer in blends. This indicated that the addition of the DAOP prepolymer effectively improved processability. The phase separation occurring during curing of the blend and the transition from the static to dynamic mode significantly influences the development of the morphology of the blend corresponding to limited evolution of the conversion around the gel point.


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