Transparent polypropylene research and development status

2014-11-12

High transparent polypropylene (PP) has not only ordinary PP tasteless, non-toxic, corrosion resistance, high temperature resistant characteristics, but also has high heat distortion temperature, good rigidity, high tensile strength and fast crystallization rate, transparency and other resin such as polystyrene (PS) and poly stupid 2 formic acid alcohol ester (PET), polyvinyl chloride (PVC), polycarbonate (PC), such as price is better than that of PS, PET, PVC, PC. In recent years, the research and development of high transparent polypropylene has become the research focus in the international big companies and universities, and launched a commercial product. Therefore, since the advent of high transparent polypropylene was developed quickly all over the world.

1 the anti-reflection principle of polypropylene

Crystallinity of polypropylene and its spherulite size uniformity is a major cause of lead to low transparency. As the amorphous phase in the polypropylene crystallization under the coexistence of the existence of the phase interface, its on the incidence of visible light scattering phenomenon. The polypropylene melt in the cooling crystallization process, external melt crystallization speed is quick, the generated crystallization is small, and the internal speed is slow, the generated large spherulite. Large spherulite size is greater than the wavelength of incident light and thus to visible light refraction. Therefore improve the main method is to reduce polypropylene crystallinity of polypropylene transparency, reduce the spherulite size.

2 anti-reflection way of polypropylene

At present, there are three kinds of production of transparent PP resin way: 1) add transparent nucleating agent; 2) direct preparation of low degree of crystallinity of random copolymerization PP; 3) using metallocene catalyst. If polyester transparency is defined as 100%, 47% high crystalline PP transparent, join the transparency of the PP transparent nucleating agent production is 89%, and the transparency of random copolymerization polypropylene was 92%, the transparency of metallocene random copolymerization polypropylene can be up to 96%.

3 transparent in toughening modification of polypropylene

Due to the special structural characteristics of transparent polypropylene, compared with ordinary PP, transparent PP has very low crystallinity and fine crystal crystal shape, the structure of different lead to the differences of material physical properties, such as: the crystallization temperature of transparent PP, PP transparent modified, a large number of crystal nucleus causes the extreme homogenization of crystalline structure, transparency and glossiness significantly increased; Extremely uniform refine spherulite structure, crystallization temperature and vicat softening temperature and hardness also increased; To improve its transparency, or surface gloss, enhance the environmental adaptability.

The application of 4 high transparent polypropylene

Transparent polypropylene not only have excellent transparency and gloss, but also has high heat distortion temperature. Due to its high cost performance, transparent PP compared with traditional transparent material (PET, PS, etc.) has a wider application range and more broad application prospects. According to statistics, in recent years, the growth of transparent PP products production speed is higher than the conventional PP products.

4.1 the disposable tableware

Currently on the market of disposable tableware mainly PS high impact polystyrene blend as a raw material for preparation, hot forming and transparent PP compared with PS, HIPS blend has higher impact resistance, better dimensional stability and better flexibility, produce the products will not burst, sealed well. Such products, raw materials consumption accounts for about 10% of the transparent PP market in China.

4.2 a microwave cooker

Due to the PP thermal deformation temperature is relatively high, generally higher than 110 ℃, some can reach more than 135 ℃, will not make because of the high temperature of the microwave cooker damaged and contaminated food. But overall, the product raw material consumption is less, accounting for about 9% of the domestic market.