Preparation of MBSB Composites

In general, the tensile strength of the composites based on concentrated emulsions is higher than that based on bulk polymerization the elongation at the break point and the toughness are, however, a little lower. 

3 Poly(vinylidene chloride)/Poly(butyl methacrylate) Composites Prepared via the Concentrated Emulsion Pathway [29] 

The copolymers of vinylidene chloride (VDC) and BMA have high flexibility. Their tensile strength and toughness can be further improved by including proper amounts of VDC and BMA homopolymers. The melt mixing method cannot be used because the melting point of PVDC is high (nearly 200°C) [31]. The inclusion of the homopolymers via the concentrated emulsion method can, however, be easily achieved. Three preparation procedures were employed to 

Procedure 1 [29,34]-first, separate concentrated emulsions of the two monomers, using an SDS aqueous solution containing the redox system as the continuous phase, were prepared. Each of the two concentrated emulsions was partially-polymerized at 45 °C until a 5% conversion was achieved. Subsequently the two concentrated emulsions were mixed. The mixture thus obtained was further heated at 45 °C to complete the polymerization. The obtained composites were washed with methanol and dried under vacuum at room temperature. 

Procedure 2 [29] - PBMA was dissolved in VDC monomer to form a solution of 2 wt%. This solution replaced the VDC monomer of Procedure 1 the other steps have been as in Procedure 1. 

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