Effect of in-situ polymerization

Effect of In-Situ Polymerization on Biodegradation Behavior of Cellulose Nanocomposites... 

The good solvent resistance of polyolefins has effectively prevented the use of solution processing as a viable and industrially acceptable preparation method for nanoclay composites. Polyolefin/nanoclay composites have been almost exclusively prepared via melt compounding, with few cases of in situ polymerization. In the following sections, these preparation methods are analyzed in more detail. 

Since reactive monomer BA and crosslinking agent TMPTA were melt compounded together with nano-silica and PP, the effect of in situ crosslinking polymerization on the microstructure of nano-silica/PP composites should be... 

This is a highly polar polymer and crystalline due to the presence of amide linkages. To achieve effective intercalation and exfoliation, the nanoclay has to be modified with some functional polar group. Most commonly, amino acid treatment is done for the nanoclays. Nanocomposites have been prepared using in situ polymerization [85] and melt-intercalation methods [113-117]. Crystallization behavior [118-122], mechanical [123,124], thermal, and barrier properties, and kinetic study [125,126] have been carried out. Nylon-based nanocomposites are now being produced commercially. 

The first reported study of a reaction of wood with an epoxide appears to be that of McMillan (1963). This involved the use of gaseous ethylene oxide (Figure 4.9, R=H) at a temperature of 93 °C and a pressure of 3 atmospheres (0.3 MPa). In some cases, the wood was diffusion pre-treated with trimethylamine vapour as the catalyst. A 65 % ASE at 20 % WPG was obtained, attributed to a bulking effect due to in situ polymerization of the epoxide. There was no effect on the static bending strength of samples, and the modified wood became distinctly brown at higher levels of treatment. 

Fig. 9 Scanning electron micrographs of a Zn2Al/Cl, and its PSS derivatives obtained b via monomer intercalation c followed by in situ polymerization, or d by direct polymer incorporation using the memory effect with e subsequent hydrothermal treatment and f after a delamination-restacking process. The bar represents 5 xm. Reprinted from [43] and [48] with permission from ACS and RSC, respectively...

Grafting by in situ Polymerization of Butadiene. The polymerization of butadiene to a high cw-1,4-polybutadiene with a catalyst system containing diethylaluminum chloride and a cobalt compound is now a well established technique (1, 9,15,18, 22). This catalyst system is particularly effective when the cobalt compound is soluble in the reaction medium. 

Pande et al. (25) also reported significant improvements in the flexural properties of MWCNT-PMMA composites prepared by in-situ polymerization method. They observed a maximum reinforcing effect of CNTs at 3 wt% for a-MWCNT and at 1.8 wt% for f-MWCNT. The flexural strength for the two cases was about 90 MPa as compared to about 64 MPa from two step method... 

Yang et al. 2005 (59) MWCNT CVD Purified In situ polymerization CNT Loading levels 0.05 to 2.5wt% Block Specimens Microhardness increased, friction coefficient decreased and wear rate decreased with increasing CNT content SEM analyses of worn surfaces of PMMA showed the positive effect of CNTs on tribological behavior of composites ... 

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