1 What is the sort of flexible size of polyethylene polypropylene polystyrene causes

The structural formula of polystyrene is a linear structure, but there are large continuously spaced large phenyl groups on the carbon atoms of the molecular chain, which determines the special properties of polystyrene. 1. Rigid texture and low impact strength; The random configuration of polystyrene has good luster, high light transmittance and good colorability. 2. The softening temperature is 80, below 80 it is a solid as hard as glass, and above 80 it becomes a softer object, with rubber-like properties, and should be avoided at high temperatures.

3. Good molding performance, small shrinkage deformation and stable size of the finished product within the range of service temperature; Good water resistance, chemical stability decreases with the increase of temperature; It has good resistance to a certain concentration of inorganic acids, organic acids, salt solutions and alkalis, alcohols, vegetable oils, etc., and will gradually turn yellow when placed in sunlight for a long time

I don't agree with what the friend said above. For non-polar substituents, the larger the group volume, the greater the steric hindrance, the more difficult it is to rotate internally, and the worse the flexibility. So polystyrene.

The molecular chains are more flexible than polypropylene.

smaller, the latter is more flexible than polyethylene.

Small. There are many factors that affect flexibility.

1) Molecular structure The structure of the backbone substituent branched and cross-linked The length of the molecular chain.

2) External factors: temperature, external force, solvent.

If you want to know more about it, I recommend taking a look at the reference book on polymer physics, thank you.

When the side group is a rigid group, the influence of the volume of the group is considered as a steric hindrance, and the larger the volume, the greater the steric hindrance, the difficulty of intramolecular rotation, and the poor flexibility. Therefore, polystyrene is the least flexible.

The methyl group is not a rigid group, so it cannot be considered from the volume size of the side group. In terms of polarity, the polarity of methyl group is greater than that of hydrogen atom, and the intermolecular force is strong and the flexibility is poor. So polypropylene is less flexible than polyethylene.

According to the number of carbon atoms, the more c, the better the flexibility, which is due to the structural characteristics of c, such as the addition of carbon elements in pig iron, the more the softer the race.

Summary. Hello, for example, the compliance ranking: the 5 materials are polystyrene, polyethylene, polyacrylonitrile, polyvinyl chloride, and polypropylene.

Simply speaking of flexibility, the order is: PE, PP, PAN, PVC, PS, the reason is that PE is a straight chain, there is no side group, the steric hindrance of macromolecules is small, the side group of PP is methyl, the side group of PAN is CN group, the side group of PVC is Cl group, and the side group of PS is phenyl group. The steric hindrance increases sequentially.

Hello dispel the finches, for example, the compliance ranking: the 5 materials are polystyrene, polyethylene, polyacrylonitrile, polyvinyl chloride, and polypropylene. Simply speaking, Naki is flexible, in order:

PE, PP, PAN, PVC, PS, the reason is that PE is a straight chain, there is no side group, the steric hindrance of macromolecules is small, the side group of PP is methyl, the side group of PAN is CN group, the side group of PVC is Cl group, and the side group of PS is phenyl group. The steric hindrance increases sequentially.

There is a big difference between the two, the first styrene is a chemical raw material synthesized from benzene and ethylene, which exists in the form of monomer and will gradually oxidize when exposed to air, and polyvinyl chloride is a white powder, which is commonly known as PVC, which is relatively brittle. Second, their uses are different, styrene is generally used in the production of polystyrene, styrene-butadiene rubber and other chemicals or pharmaceutical products, polyvinyl chloride is generally used in the manufacture of pipes, and thirdly, their production processes are different. Hope it helps.

Polyethylene: Flat zigzag Polypropylene: spiral structure, polyethylene Advantages:

Low temperature resistance, solvent resistance, toughness, good dielectric and electrical insulationPolypropylene advantages: boiling water resistance, steam resistance, solvent resistance, good dielectric and electrical insulationPolyethylene disadvantages: small bearing capacity, flammable, poor weather resistance.

Disadvantages of polypropylene: poor toughness, cold resistance, dyeability, and dimensional stability.

Polystyrene is made by polymerization of styrene monomer. Styrene monomer is made of benzene and ethylene as raw materials, and ethylbenzene is obtained through liquid-phase rooting reaction, and then ethylbenzene is catalyzed by dehydrogenation to produce styrene.

Polystyrene (PS) is a colorless and transparent, hard and brittle, glass-like, odorless, non-toxic amorphous plastic; There is a crisp metallic sound when struck; It is flammable, emits black smoke when burning, and emits a special odor at the same time; The product has high stiffness and surface hardness, good dimensional stability, low impact strength and poor wear resistance; Excellent electrical properties, especially good high-frequency insulation, poor sunlight resistance; Resistant to water, acids, alkalis, poor oil resistance, soluble in aromatic hydrocarbons, chlorinated hydrocarbons, ketones and esters. The performance parameters of general-grade polystyrene are shown in Table 1. Polystyrene standard (GB12671-1990) is shown in Table 2.

The temperature tolerance and toughness of ABS are better than PS!

Polymerized from styrene monomer, the main product of polystyrene is general-purpose grade polystyrene.

1.General purpose grade polystyrene properties.

Colorless, non-toxic, odorless amorphous transparent thermoplastic.

The stiffness and surface hardness are large, and the dimensional stability is good, but the brittleness is small, the impact strength is small, and the wear resistance is poor.

Low softening point (80 90) and can only be used at 60 75 and low loads.

Good colorability, surface decoration, and radiation resistance.

Excellent electrical properties, especially high frequency insulation performance, good arc resistance.

Poor sunlight resistance, flammable, black smoke when burning, and special odor.

It is resistant to water, acid and alkali, but soluble in aromatic hydrocarbons, chlorinated hydrocarbons, ketones and esters, etc., with poor oil resistance and no resistance to hot water.

2.Molding processing method.

It has good molding processing performance, and can be injection molding, extrusion, blow molding, foaming, thermoforming, bonding, coating, welding, machining, printing, etc.

3.Use.

It can manufacture all kinds of transparent or brightly colored products, such as daily necessities, stationery, lamps, indoor and outdoor decorations, cosmetics, containers, instrumentation, car lights, optical parts, transparent window mirrors, telecommunication components, high-frequency capacitors, high-frequency insulating materials, televisions and other container boards, which can be made into foam plastics of different densities, used as thermal insulation, heat insulation, shockproof, floating, packaging materials, cork substitutes, pre-foamed body can be used as water filtration medium and preparation of lightweight concrete, low foam plastic can be made into synthetic wood for furniture, etc. Glass fiber reinforcement can improve its heat resistance, impact resistance, and coefficient of thermal expansion.