Polymers are also called adducts. The product of polymerization (addition polymerization) of a monomer. Molecules have repetitive structural units. Low molecular weight is called oligomer, such as trimeric formaldehyde. Those with high molecular weight, up to thousands or even millions, are called polymers or high molecular compounds. In this article, Qingdao Sainuo polyethylene wax manufacturer will take you to know about polymer transparency modification and light diffusion modification.

1. Transparent modification

The transparency of polymer is related to the crystallinity and crystal quality of polymer products. Therefore, the transparency of polymer products can be greatly improved by controlling different crystallinity and different crystal morphology and structure.

1.1 reduce the crystallinity of products

The lower the crystallinity of polymer products, the higher the transparency of products. The reduction of crystallinity is mainly realized by process conditions.

1.2 improve product crystallization quality

The same polymer products with the same crystallinity have different crystal quality and transparency. The crystallization quality can be controlled either by process conditions or by adding nucleating agent. The crystallization quality that can affect the transparency mainly includes:

① Crystal form, taking PP as an example, it has a β、γ、δ And pseudo hexagonal, in which β The increase of crystal form and quasi hexagonal crystal form is conducive to improve the transparency of products. In the specific process, quenching can produce more quasi hexagonal crystal forms β High content of crystal nucleating agent can be obtained β Crystal form.

② Spherulite content, spherulite has a great influence on the transparency of products. The greater the spherulite content, the worse the transparency of products. The generation of spherulites is related to the cooling temperature, and the probability of spherulites produced by quenching is small.

③ Crystal size, whether spherulite or general crystal, the smaller the crystal size, that is, the finer the grain, the more conducive to the improvement of transparency. Low temperature processing, quenching, stretching and adding nucleating agent can reduce the crystal size.

④ Crystal regularity: the more regular the crystal structure of polymer products is, the more conducive to the improvement of transparency. The stretching process can improve the regularity of polymer products.

2. Light diffusion modification

Light diffusion polymer is a kind of light transmitting material that disperses visible light point light sources into uniform area light sources. The essence of light diffusion polymer is to improve the haze of materials on the premise of ensuring high light transmittance of materials, and find a balance between the two. Among many optical indexes, transmittance and haze are two contradictory indexes. The higher the haze, the greater the amount of scattered light and the lower the transmittance, which is the difficulty in the manufacture of light diffusion materials.

Sainuo pp wax

At present, the main method is to add light diffusing agent. Its essence is a kind of spherical microspheres close to nano size, which can transmit and scatter visible light. The light diffusing agent can be added to transparent resins such as PC, PVC, PS, PMMA, pet, epoxy resin and LED (light emitting diode). At the same time, it can increase the scattering and transmission of light, cover the dazzling light source of point light source, and make the whole resin emit softer, beautiful and elegant light, so as to achieve the comfortable effect of transparent and opaque. 

Light diffusing agents mainly include inorganic light diffusing agents and organic light diffusing agents:

① The main varieties of inorganic light diffusing agents are nano silica, nano barium sulfate, nano calcium carbonate, etc.

The light diffusion principle of inorganic light diffusing agent is as follows: light passes through the surface of inorganic light diffusing agent particles and uses the difference of refractive index between inorganic light diffusing agent and matrix resin to produce light refraction, so as to achieve the effect of light diffusion, i.e. uniform light. For the inorganic light diffusing agent, the incident light cannot pass through the inorganic particles, and only part of the light passes through refraction. Therefore, the light energy loss is large, and the brightness of the light is reduced at the same time of light diffusion. In general, inorganic light diffusing agent cannot be selected for lamps with a transmittance of more than 50%. Inorganic light diffusing agent particle size 2-3 μ m. The refractive index is 1.41-1.43, and the addition ratio is about 0.6%.

② Organic light diffusing agent is a kind of microsphere products with uniform particle size distribution synthesized by means of cross-linking and grafting functional groups through polymer polymerization technology, mainly including silicone type, plexiglass type, styrene type, acrylic resin type, etc.

The light diffusion principle of organic light diffusing agent is that light passes through the surface of organic light diffusing agent particles and uses the difference of refractive index between organic light diffusing agent and matrix resin to produce light refraction, so as to achieve the effect of light diffusion, i.e. uniform light. For organic light diffusing agents, they are transparent or translucent materials, and most of the incident light can be transmitted. Therefore, the loss of light energy is very small. At the same time, the light diffusion basically does not affect the brightness of the light. For organic light diffusing agent with high light transmittance, it is a good choice for optical materials such as lamp tube and lampshade. Organic light diffusing agent particle size 3-5 μ Um, the refractive index is about 1.50, and the addition ratio is 1% - 2%, in which the effect of silicone light diffuser is more obvious.

Sainuo aluminate coupling agent 

Comparison of light diffusion principle between inorganic light diffusing agent and organic light diffusing agent: when inorganic nano light diffusing agent is added into transparent polymer, light will refract countless times through the surface of small particles to achieve light diffusion, i.e. uniform light. But the light diffusing agent here is inorganic after all. Light cannot penetrate inorganic molecules, and the light energy loss is very large. The inorganic light diffusing agent has no antireflection effect, and can only play the role of uniform light. Organic nano bead light diffusing agent can transmit light itself, which well solves the problem of uniform light and light transmission. This kind of light diffusing agent achieves the effect of soft light through multiple light refraction through the different refractive index of substrate and bead. At the same time, it plays the role of uniform light and light transmission, among which the effect of silicone light diffuser is more obvious.

Qingdao Sainuo Chemical Co., Ltd. We are manufacturer of PE wax, PP wax, OPE wax, EVA wax, PEMA, EBS, Zinc/Calcium Stearate…. Our products have passed the REACH, ROHS, PAHS, FDA testing. 

Sainuo rest assured wax, welcome your inquiry!

Website：https://www.sainuowax.com

E-mail：sales@qdsainuo.com

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