An acryl monomer containing the quinolone moiety was synthesized and then polymerized with azobisisobutyronitrile in a dimethylformamide solution. The resulting polymer as well as the corresponding monomer exhibited an excellent antibacterial activity. The poly(acrylated quinolone) (PQ) was compounded with other ordinary synthetic polymers such as low-density polyethylene (LDPE), poly(butylene succinate) (PBS), poly(methyl methacrylate) (PMMA), maleated polypropylene (PPMA), and polycaprolactone (PCL). The polymer blends reduced the viable cell number significantly on contact during the shake flask test even when the PQ content was as low as 1 wt %.

Polyethylene (PE) and polypropylene (PP) were reacted with benzoyl peroxide (BPO) and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) to prepare PE-TEMPO and PP-TEMPO macroinitiators, respectively. Molecular weight of PP decreased, whereas that of PE increased during the reaction with the BPO/TEMPO system. Polystyrene (PS) branches were grafted to PE and PP backbone chains as a result of bulk polymerization of styrene with the PE-TEMPO and PP-TEMPO macroinitiators. A significant amount of PS homopolymer was produced as a byproduct. Weight of the resulting PE-g-PS and PP-g-PS increased with the polymerization time up to 20 h and then leveled off. Melting point of PE and PP domains in PE-g-PS and PP-g-PS, respectively, lowered as the content of PS in the copolymers increased. However, glass transition of the copolymers was almost identical with that of PS homopolymer, indicating that the constituents in the copolymers were all phase-separated from each other. In scanning electron microscopy of the incompatible PE/PS, PP/PS, and PE/ PP/PS compounded with PE-g-PS and PP-g-PS, any clear indication of enhanced adhesion between the phases was not observed. However, phase domains in the blends were, nevertheless, reduced significantly to raise mechanical properties such as maximum stress and elongation at break by 20 -75%.

ABSTRACT:The ring-opening polymerization of -caprolactone was carried out with poly(ethylene-co-vinyl alcohol) as a macroinitiator to synthesize poly(ethylene-co-vinyl alcohol)-graft-polycaprolactone (EVOH-g-PCL). A simple lowdensity polyethylene (LDPE)/polycaprolactone (PCL) (64/ 36) blend lost 5.3 wt % of its original weight after 90 days of a soil burial test. However, the elongation at break of the LDPE/PCL blend remained almost invariable even after the solid burial test because the tensile properties depended mostly on the LDPE phase on account of the poor interaction between the continuous LDPE matrix and the dispersed PCL phase. For EVOH-g-PCL, the elongation at break decreased drastically as a result of the soil burial test, and the reduction of the elongation at break was more pronounced for EVOHg-PCL with a higher PCL concentration, even though the weight loss of EVOH-g-PCL after the soil burial test was as low as 1.2-1.3% and was nearly independent of the PCL concentration. Few holes were observed in EVOH-g-PCL when the PCL concentration was less than 26 wt % after an accelerated hydrolysis experiment at 60°C for 7 days in a 0.1M KOH solution. In contrast, the hydrolysis formed small holes in EVOH-g-PCL with a PCL concentration of 36 wt %. The LDPE/PCL blend was much better percolated, as a result of the hydrolysis, than EVOH-g-PCL with the same PCL concentration; the soil burial test showed the same results.

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