Study On Properties Of New Wood Plastic Composite

The physical-mechanical properties, aging properties, temperature effects, water effects, decay resistance, and properties of acid-proof, salt-proof, and alkaline-proof of three new wood-plastic composites are studied in the paper, including: red diapers scrap/PE material, white diapers scrap/PE material, and recycled milk cartons/PE material. The conclusions are as follows:1. The 24-hour thickness swelling of three new WPCs is lower; The impact strength of three new WPCs is higher than traditional WPCs, MOR and MOE are similar with traditional WPCs, creep resistance is consistent with traditional WPCs, and the effect of creep test on residual bending strength is not very obvious.2. The change of surface color of three new WPCs is from identical to large put in the sun environment and outdoor natural dry and wet environment for six months, and the MOE and MOR initially decreased and then increased as time passed; the change of surface color of three new WPCs is from large to very large put in Xenon Weathering resistant box for 1500h., and the MOE and MOR decreased significantly. The retention of residual MOE and MOR in Xenon Weathering resistant box for 1500h is equivalent with them in the sun environment and outdoor natural dry and wet environment for six months; the color change of red WPC with color agent is less than white WPC without color agent in any environment.3. Both water absorption rate and size swell rate increase as temperature increased until balance treated in 23℃,60℃and boiling water for about 30 days, the rule of size swell rate of different directions is: thickness﹥width﹥length, and water resistance is excellent; the MOE and MOR of three new WPCs decreased a lot when treated in 23℃,60℃and boiling water for about 30 days, but the degree of decline is approaching to traditional WPCs.4. The size change of three new WPCs is consistant with the law of thermal expansion and contraction when put in four typically temperature environment for 15 days, including: 52℃,85℃,-29℃and -40℃. The rate of size change of thickness direction is largest, and it has no significant difference between length direction and width direction; the MOE and MOR of three new WPCs decreased a lot when treated in 52℃and 85℃for 30 days, and both of them show increasing trend when treated in -29℃and -40℃for 30 days. The MOE and MOR of three new WPCs decreased much more as temperature difference and cycle time increased when experiencing different temperature ranges of the freeze-thaw cycle. Compared with a single temperature test, the MOE and MOR decreased much more after the freeze-thaw cycle test.5. The properties of decay-resistant of three new WPCs: The quality of three new WPCs has increased 2.31%-4.19% after decay. The change of surface color of three new WPCs is lager, very large, and very large in the soil environment for six months. The impact strength of three new WPCs decreased 11.09%-35.93% in the soil environment for two months. The MOE and MOR decreased a lot in the soil environment for six months. Both water absorption rate and size swell rate increase much more after decay treated in 23℃, 60℃, and boiling water for 15 days, which shows that decay has an important effect on the dimensional stability properties of three new WPCs.6.In the artificial simulated seawater condition, the quality of three new WPCs increased as time passed when treated in the seawater of 10‰,35‰,50‰for 60 days, and the MOE and MOR of three new WPCs decreased as time passed. In the artificial simulated acid rain condition, the quality of three new WPCs increased as time passed when treated in the H2SO4 of PH=1.5, PH=3 and PH=5.6 for 60 days, and the MOE and MOR of three new WPCs decreased as time passed. The quality of three new WPCs increased as time passed when treated in the NaOH of PH=8,PH=11 and PH=13 for 60 days, and the MOE and MOR of three new WPCs decreased a lot as time passed.