Structure-Property Relationship in Rubber-Modified Propylene-Ethylene Block Copolymer Blends

1988 ◽  
Vol 61 (5) ◽  
pp. 747-759 ◽  
Author(s):  
M. M. Sain ◽  
I. Hudec ◽  
J. Beniska ◽  
P. Rosner

Abstract The incorporation of a phase modifier, as is well known in the case of elasto-plastic blends, leads to an improvement of mechanical properties and brittleness character for PRP-EVA blends. Similarly, the influence of a cocuring agent and a phase modifier on NR-PRP blends also improved the mechanical properties. Although the modification of the PRP-EVA blend has very little influence on glass transition temperatures, the NR-PRP blends show a measurable shift in their glass-transition temperatures. It is demonstrated that strong interaction occurs between the elastic and plastic components of the blends. Further, it has been shown that this interaction is responsible for improved properties of the blends over that of the pure polymer components.

2020 ◽  
Vol 11 (37) ◽  
pp. 6009-6016
Author(s):  
Jie Miao ◽  
Xiaofan Hu ◽  
Xianwei Wang ◽  
Xiangsheng Meng ◽  
Zhen Wang ◽  
...  

Colorless polyimides with high glass transition temperatures (up to 440 °C) were developed from three adamantane-containing diamines, and the structure–property relationship of this series of polyimides was established.


Author(s):  
Kobra Tajaddodi Talab ◽  
Mohd. Nordin Ibrahim ◽  
Sergey Spotar ◽  
Rosnita A. Talib ◽  
Kharidah Muhammad

Abstract Glass transition temperatures (Tg) of MR219 rice variety were measured by differential scanning calorimeter (DSC). State diagram was developed and used to evaluate drying process in this study. Glass transition temperatures range of 9.65- 61.79°C were observed for gains with moisture content of 26.8 – 7.4% (w.b.). For mechanical properties and milling test, statistical analysis was performed by using a two factor experiment in completely randomized design (CRD). Two selected factors were drying temperatures at 5 levels (40, 45, 50, 55, and 60°C) and final moisture content (FMC) at 4 levels (10-10.5, 11-11.5, 12-12.5 and 13-13.5%). Three–point bending test was applied to measure the mechanical properties of rice kernel. Generally, bending strength, apparent modulus of elasticity and fracture energy of brown rice kernel increased with decreasing the grain moisture content. Maximum bending strength was 35.69 and 33.64 MPa for 55, and 60°C, respectively. All samples that were dried at 55 and 60°C experienced to go through the glass transition line after reaching their temperature to the room temperature at the end of drying process. The effect of drying temperature, paddy FMC and their interactions on whole kernel percentage (WKP) and mechanical properties were significant (α = 0.05). An inverse relationship was observed between WKP and the percentage of strong kernels for all treatments.


2016 ◽  
Vol 29 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Xiaodong Ji ◽  
Jingling Yan ◽  
Xiuju Liu ◽  
Zikun Wang ◽  
Zhen Wang

Several partially bio-based polyimides have been successfully synthesized by polycondensation between bis(4-aminophenyl)isohexides with various commercial dianhydrides. Flexible and free-standing films were readily obtained from their poly(amic acid) or polyimide solutions. A systematic investigation of the structure–property relationship of polyimides highlights the significant impact of the isohexides moieties on their physical and mechanical properties (glass transition temperature, inherent viscosity, thermal stability, solubility, and mechanical properties). The results revealed that these polyimides exhibited comparable thermal stability and mechanical properties to those of petrochemical-based ones.


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