Preparation method of foaming modifier for foaming PVC (poly vinyl chloride) wood-plastic composite

Abstract

The invention relates to the field of foaming PVC (poly vinyl chloride) wood-plastic composites and relates to a preparation method of a foaming modifier for a foaming PVC wood-plastic composite. The preparation method of the foaming modifier for the foaming PVC wood-plastic composite is characterized by comprising the following steps: weighing copolymerization monomer, deionzed water and emulsifier in mass ratio of 1.0:(0.5-1.0):(0.02-0.05); weighing copolymerization monomer, oxidant and reducing agent in mass ratio of 1:(0.015-0.005):(0.015-0.005); dropwise adding the rest two thirds of seed emulsion after blue lights appear in the emulsion, reducing temperature of a heating sheath to be 60-65 DEG C, and adding the same amount of initiator every half hour for five times. By virtue of adoption of the technical scheme, an oxidation-reduction system is taken as an initiator, multi-stage emulsion polymerization is adopted, a core-shell structure is prepared, viscosity of a polymerization product is greatly improved, and finally a reaction temperature is increased for increasing conversion rate of a monomer; meanwhile, the monomer is dropwise added and the initiator is added in stages, so that gel content can be greatly reduced.

Description

technical field [0001] The invention relates to the field of foamed PVC wood-plastic composite materials, and relates to a preparation method of a foam regulator for foamed PVC wood-plastic composite materials. Background technique [0002] PVC wood-plastic composite material refers to the use of polyvinyl chloride, mixed with wood powder, rice husk, bamboo powder and other plant fibers to form new wood materials. The composite material uses agricultural and forestry waste such as wood flour, which is economical and environmentally friendly; it can be used instead of wood in packaging, load-bearing and other fields, and has development advantages in the fields of construction, decoration and automobiles; with the expansion of PVC consumption fields, PVC wood-plastic composite materials have Potential, wider application fields. However, due to the small bonding force between hydrophilic wood fibers and hydrophobic plastics, the mechanical strength of the product is reduced. ...

AI Technical Summary

Problems solved by technology

However, most of the polymers studied at home and abroad have a linear chain structure, and it is difficult to avoid the disadvantages of uneven cell structure and cell collapse, and the method of preparing high molecular weight (high viscosity) polyacrylate is widely used in large-scale industrial batch production. When the reaction temperature is too high, the reaction temperature cannot be controlled due to the rapid heat release, resulting in the explosion of the gel phenomenon. In addition, the polymerization temperature is too low and the production efficiency is also reduced.