Physical properties PVAC

However, the presented cement-in-polymer dispersions usually contain up to 20 wt-% of the polymer. It is, therefore, not surprising to see a pronounced influence of the polymer on the pull-out performance in Fig. 1. Although both coated rovings clearly outperform the uncoated one, the roving coated with the cement-in-poly(vinyl alcohol), c/PVA, fails at approximately half the load of the cement-in-poly(vinyl acetate), c/PVAc. The reason for this is likely to come from the differences in the chemical and physical properties of the polymers. 

The physical properties of PVA depend to a greater extent on the method of synthesis than do those of most other polymers. This is because the final properties are affected by the polymerization of the parent PVAc, hydrolysis conditions, drying, and grinding (1). For example, the degree of hydrolysis determines the final glass transition temperature of PVA, usually between 58 and 85 °C. 

PLA/poly(vinyl acetate) (PVAc) blends have been reported by Gajria et al. regarding their miscibility, physical properties, degradation and surface tension. The blends show a miscible phase, and the mechanical properties of the blends exhibit a synergism in the range of 5 to 30% PVAc content. However, the addition of PVAc to PLA leads to a dramatic decrease in the degradation rate for enzymatic degradation. On the contrary, the nonenzymatic and enzymatic hydrolysis of PLA is accelerated by the presence of the hydrophilic PVA, but these blends is... 

Wherever possible we will therefore focus on degradation studies with pure polymers. The degree of biodegradation of PVAc and PVA depends on characteristics that are intrinsically related to the physical and chemical properties of the polymer. As many of these factors can differ to some extent depending on the... 

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