Studies on impact modification and fractography of solution cast blends of PVC and NR/PU block copolymers |
| |
Authors: | M N Radhakrishnan Nair M R Gopinathan Nair |
| |
Affiliation: | (1) P.G. Department of Chemistry, D.B. College, Thalayolaparambu P.O., Kottayam, 686605, Kerala, India;(2) School of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills P.O., Kottayam, 686560, Kerala, India |
| |
Abstract: | Segmented polyurethanes based on toluene diisocyanate (TDI) with three different chain extender diols, viz., propylene glycol
(PG), 1,4-butanediol (1,4-BDO), and 1,3-butanediol (1,3-BDO) were synthesized by a two-step, solution polymerization method.
These different NR-b-PU block copolymers were incorporated into PVC at various compositions by the solution blending method. These blend systems
were subjected to FTIR analysis, DSC, tensile testing, tensile impact measurements, and tensile impact fracture studies by
SEM. It was observed that systems showed modification in tensile impact properties. Optimum impact properties were shown at
concentrations 6–8% of the block copolymer. At higher compositions there is deterioration in impact properties. High impact
properties showed by these blends are attributed to the optimum level of compatibility achieved between the blend components.
Tensile impact fracture studies revealed that failure pattern for these blend system transitioned from brittle to ductile
fracture. Blends up to 10 wt% of block copolymer showed partially compatible heterogeneous nature exhibiting domain morphology.
Blends with higher block copolymer content showed deterioration in tensile strength, modulus, yield strength, and tensile
impact strength due to higher particle size of the agglomerated rubber soft segments of the block copolymer. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|