Effect of mechanochemical degradation on gelation and mechanical properties of PVC

Abstract

The effect of vibromilling or jet milling on gelation and mechanical properties of poly(vinyl chloride) (PVC) was studied through SEM, FTIR, DSC, and mechanical properties tests. The experimental results show that the size of the grain and apparent density of PVC are decreased. The grains become much more loosely aggregated and the crystallinity of PVC is decreased during milling. The extensional fracture of degraded PVC is obviously different from that of undegraded PVC, the tensile strength and degree of gelation of degraded PVC are increased as compared with undegraded PVC. The mechanical properties of PVC are improved quite a lot after blending it with a small amount of mechanochemically degraded PVC.

Effects of acrylic‐based processing aids on processibility, rheology, thermal and structural stability, and mechanical properties of PVC/wood–sawdust composites

“…The increase in T g was associated with an increase in entanglement level due to the presence of the processing aids. As the degree of entanglement increases, the molecular chains become more difficult to mobilize 24. It was also found that the T g value of PVC/sawdust composites with PA20 was higher than with K120 and K130 for a given processing aid content due to the higher effectiveness of PA20 as stated.…”

Mechanodegradation

“…6 Jet milling produced comparable results in molecular weight reduction. 6 Figure 8.5 shows that crystallinity is also decreased (1435 cm -1 and 1427 cm -1 are amorphous and crystalline absorption bands, respectively). 6 (CH 2 CHCl) + CaO (CH CH) + CaOHCl shows that the dehydrochlorination rate increases with increasing ball diameter.…”

“…• extrusion, 1,2 • injection molding, 2,3 • milling and grinding, [4][5][6][7][8] • PVC mixing with additives, 9 • Brabender plastograph mixing, 10 • capillary and torque rheometry, [11][12][13] • processed materials. [14][15][16] Repeated extrusion is frequently used to estimate the effect of processing on a particular formulation.…”

Mechanochemical improvement of the flame‐retardant and mechanical properties of zinc borate and zinc borate–aluminum trihydrate‐filled poly(vinyl chloride)

“…Our previous work 25 showed that a complex combination of the shearing, extension, tearing, collision, fracture, and cold-drawing of PVC powder during vibromilling could induce chain scission and generate free radicals. Chain scission was accompanied by a reduction in molecular weight in the presence of a radical acceptor.…”

“…They provide a potential route for the preparation of innovative polymeric materials with special properties and for the enhancement of the compatibility of incompatible polymer blends. [21][22][23][24][25][26] To enhance the flame-retardant and mechanical properties of ZB and ZB-ATH-filled PVC, the mechanochemical modification of ZB and ZB-ATH by high-energy mechanical milling and its effect on the flame-retardant and mechanical properties of PVC were studied in this work. The effect of the mechanochemical modification of flame-retardant and smoke-suppressant additives on the release of aromatic compounds during the burning of PVC was characterized by ultraviolet (UV) spectroscopy and gas chromatography-mass spectrometry (GC-MS).…”