CN102675711A

CN102675711A - High-strength PE (polyethylene), production process of high-strength PE and application of high-strength PE to variable-pitch electro-fused pipe fitting

Info

Publication number: CN102675711A
Application number: CN2012101052930A
Authority: CN
Inventors: 孙德刚; 卢培丰; 娄玉川; 王建芬; 杨峻峰; 刘伟
Original assignee: SHANGHAI GEROG FISCHER CHINAUST PLASTICS FITTING CO Ltd
Current assignee: SHANGHAI GEROG FISCHER CHINAUST PLASTICS FITTING CO Ltd
Priority date: 2012-04-11
Filing date: 2012-04-11
Publication date: 2012-09-19

Abstract

The invention provides high-strength PE (polyethylene), a production process of the high-strength PE and the application of the high-strength PE to a variable-pitch electro-fused pipe fitting. The pipe fitting is made of 100 parts of ultrahigh molecular weight polyethylene and 20-100 parts of montmorillonite nano composite polyethylene. The preparation method includes preparation of the montmorillonite nano composite polyethylene and melting extrusion and granulation of raw materials. The montmorillonite nano composite polyethylene in the high-strength PE is prepared by means of in-situ polymerization so as to be extremely high in dispersity and compatibility, the material obtained after the montmorillonite nano composite polyethylene is mixed with the ultrahigh molecular weight polyethylene has high strength, high creepage resistance and excellent processability, and the variable-pitch electro-fused pipe fitting made of the material is high in environment adaptability, safe, reliable and low in cost and has wide market prospect.

Description

Application on HS PE and production technique thereof and the varying pitch structure electric melting pipe fittings

Technical field

The present invention relates to a kind of high-strength polyethylene (PE) and working method thereof and the application on electric melting pipe fittings, be specifically related to HS PE and working method thereof and the application on nichrome wire varying pitch distribution electric melting pipe fittings.

Background technology

Polyethylene tube is one of most popular plastic pipe in the world, the tenacity excellent of polyethylene tube, shock resistance, nontoxic, and polyethylene tube can be easy to be used widely through the molten solder assembling.But, be restricted aspect its fluid-resistant its static performance owing to Vilaterm inherent low yield strength simultaneously.Adopt the crystal of the polyethylene products that traditional diamond-making technique obtains to be mainly spherocrystal, so-called autumn crystalline substance is meant the crystal that in process of growth, is bent and twisted and radially form to all directions development along nucleus by the secondary platelet of initial platelet ramose.The intensity and the modulus of the PE goods of traditional method processing are decided by spherocrystal interface region structure, platelet crystal boundary area structure and non-crystalline region structure.The spherocrystal of PE goods, platelet and non-crystalline region are to lean on the Van der Waals force of low bound energy to combine, and when receiving external force to do the time spent, are easy to take place slippage between the interface of spherocrystal, platelet and non-crystalline region, be exactly PE goods low modulus, low intensive reason.

Microtexture through changing polymkeric substance increases substantially the focus that its intensity is polymeric material field.Molecular chain is very long, side chain seldom, terminal number ultrahigh molecular weight polyethylene(UHMWPE) seldom is considered to prepare the desirable feedstock of flexible chain structural polymer self-reinforced material.But, more than melting temperature, do not have viscous state, and be elastomeric state because macromolecular chain tangles in a large number.CN1324886 discloses a kind of composite nanometer montmorillonoid-polyolefine material and preparation method.Above-mentioned patent through clay of laminar silicate through the Coulomb's force with covalent linkage combines with the Vilaterm matrix and with the nanoscale homodisperse, thereby acquisition has the montmorillonite-based nano composite polyethylene material of excellent properties, but only is used for the common polythene matrix material.Disclose among the CN1253501C under the melt condition; Adopt nano layered silicate that a large amount of random entanglement of ultrahigh molecular weight polyethylene(UHMWPE) is untied; Obtain having the mixture of certain flowability, carry out self-enhancement again and handle, obtain the super-high molecular-weight polythene self-strengthening that intensity increases substantially.But this nano layered silicate is to extrude after mixing with ultrahigh molecular weight polyethylene(UHMWPE) through intercalation processing and through the mixture that dispersion agent obtains organic clay to make.Because have the interfacial energy problem between this nano layered silicate and the ultrahigh molecular weight polyethylene(UHMWPE), consistency is poor, has had a strong impact on the self-enhancement effect.

At present, the pipeline that be used to feed water, buried pipeline all adopts plastic material mostly among the public works such as combustion gas.Wherein need use a large amount of electric melting pipe fittings, safe in utilization secure for guaranteeing pipeline, the requirement of strength of electric melting pipe fittings wants high than the requirement of tubing, and it is most important with material therefore to research and develop the low-cost high-strength pipe fitting.

Summary of the invention

The purpose of this invention is to provide a kind of HS PE and working method thereof and application, in order to solve defective and the deficiency that above-mentioned prior art exists.

Be the realization above-mentioned purpose, a kind of HS PE of the present invention, it comprises following component and content (weight part):

Ultrahigh molecular weight polyethylene(UHMWPE): 100 parts

Montmorillonite-based nano composite polyethylene: 20～100 parts;

Year average molecular weight of said ultrahigh molecular weight polyethylene(UHMWPE) is more than 1,500,000;

Further, preferred 30～60 parts of the content of montmorillonite-based nano composite polyethylene, content is crossed low poor processability, and long term hydrostatic strength is low excessively, too high levels, the reduction of ultrahigh molecular weight polyethylene(UHMWPE) self-enhancement property;

Further, said HS PE also comprises 3～6 parts active nano-calcium carbonate, and active nano-calcium carbonate when reducing cost, has guaranteed toughness and intensity as filler, has increased the market competitiveness of polyethylene tube.

The present invention provides the preparation method of above-mentioned HS PE simultaneously, and it may further comprise the steps:

1) preparation of montmorillonite-based nano composite polyethylene;

2) with raw material (weight part):

Ultrahigh molecular weight polyethylene(UHMWPE): 100 parts

Montmorillonite-based nano composite polyethylene: 20～100 parts

In high speed mixer, stir, with extruding pelletization on the twin screw extruder, promptly make HS PE;

Further, the preparation method of said montmorillonite-based nano composite polyethylene is the vinyl monomer in-situ polymerization of catalytic active center between cheating engaging layer, and the montmorillonite layer that obtains is dispersed in the Vilaterm matrix, has excellent mechanical property;

Further, in the said montmorillonite-based nano composite polyethylene, the percentage composition of polynite is 10%～30%;

Further, the preparation method comprises that also forcing machine melt extrudes, and carries out longitudinal stretching, obtains unidirectional self-reinforced material.

HS PE of the present invention can be used for preparing varying pitch structure electric melting pipe fittings; Because the HS of HS PE; High creep resistant makes the environment-adapting ability and the security of varying pitch structure electric melting pipe fittings improve greatly, and work-ing life also can significant prolongation;

The montmorillonite-based nano composite polyethylene is to get through the in-situ polymerization preparation among the HS PE provided by the invention; Therefore the dispersed consistency of nano imvite is very high, after the High molecular weight polyethylene blend, produces synergy; The material that obtains has HS, high creep resistant and excellent processibility.The varying pitch structure electric melting pipe fittings environment-adapting ability of producing thus is strong, safe and reliable and with low cost, has vast market prospect.

Embodiment

Embodiment 1

The preparation of montmorillonite-based nano composite polyethylene:

Under nitrogen atmosphere, the 20gMg-polynite joined in the 80ml ethanol, in stirring at room 30 minutes; Adding concentration again is 8% magnesium chloride ethanolic soln 100ml; 50 ℃ were reacted 3 hours, filtered the magnesium chloride ethanolic soln 100ml that the back adds same concentration, and 50 ℃ were reacted 1 hour; Handle three times after-filtration, drying obtains polynite magnesium chloride complex carrier.This carrier 5g joins under-15 ℃ in the 75ml titanium tetrachloride, and 120 ℃ were reacted 2 hours, filtered, and adds in the 75ml titanium tetrachloride again, and 120 ℃ were reacted 2 hours.After the filtration, with 60 ℃ of washings of 50ml hexane 5 times, vacuum-drying gets the supported catalyst polynite.Reaction flask fully exchanges with nitrogen and ethene; Add the 100ml heptane, 70 ℃ of n-heptane solutions that add triethyl aluminum add the supported catalyst polynite again; Ethylene pressure is under the 770mmHg condition; Carried out polyreaction 1 hour, and added acidifying ethanol termination reaction, the washing drying obtains montmorillonite-based nano composite polyethylene material.

Embodiment 2

The preparation of HS PE

With raw material (weight part):

A: 100 parts of ultrahigh molecular weight polyethylene(UHMWPE)s (1,500,000)

60 parts of the montmorillonite-based nano composite polyethylenes of B: embodiment 1 preparation

C: 3 parts of active nano-calcium carbonates,

In high speed mixer, stir, use the twin screw extruder extruding pelletization, make HS PE 100 ℃ of oven dry.

Embodiment 2～5

With the preparation method of embodiment 1 and embodiment 2, wherein montmorillonite-based nano composite polyethylene content is respectively 30 parts, 40 parts, 50 parts, 70 parts, and each embodiment mechanical property is seen table one, and mechanical property adopts U.S. ASTM method at room temperature to characterize.

Table one: embodiment 2～5 mechanical properties

Embodiment	A∶B∶C	Tensile strength (MPa)	Shock strength (J/M)
				3	100∶30∶6	?26	450
4	100∶40∶5	?30	450
				2	100∶60∶3	?36	430
5	100∶70∶6	?32	410

Embodiment 6

The HS PE that embodiment 2～5 prepares produces electric melting pipe fittings through single injection-molded.

The above; Be merely embodiment of the present invention, but protection scope of the present invention is not limited thereto, any technician who is familiar with the present technique field is in the technical scope that the present invention discloses; Can expect easily changing or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.

Claims

1. HS PE is characterized in that comprising following component and weight part proportioning:

Ultrahigh molecular weight polyethylene(UHMWPE): 100 parts

Montmorillonite-based nano composite polyethylene: 20～100 parts.

2. according to the said a kind of HS PE of claim 1, it is characterized in that preferred 30～60 parts of the content of montmorillonite-based nano composite polyethylene.

3. according to the said a kind of HS PE of claim 1, it is characterized in that also comprising 3～6 parts active nano-calcium carbonate.

4. the preparation method of the arbitrary said HS PE of claim 1～3 is characterized in that may further comprise the steps:

1) preparation of montmorillonite-based nano composite polyethylene;

2) each component raw material in the claim 1～3 is pressed the content proportioning in high speed mixer, stir,, promptly make corresponding HS PE with extruding pelletization on the twin screw extruder.

5. according to the preparation method of the said a kind of HS PE of claim 4, the preparation method who it is characterized in that said montmorillonite-based nano composite polyethylene is the vinyl monomer in-situ polymerization of catalytic active center between cheating engaging layer.

6. according to the preparation method of the said a kind of HS PE of claim 4, it is characterized in that in the said montmorillonite-based nano composite polyethylene, the percentage composition of polynite is 10%～30%.

7. according to the preparation method of the said a kind of HS PE of claim 4, it is characterized in that also comprising that single screw extrusion machine melt extrudes, and carry out longitudinal stretching, obtain unidirectional self-reinforced material.

8. the application of the arbitrary said HS PE of claim 1～3 is characterized in that being used to make electric melting pipe fittings.

9. the application of a said according to Claim 8 said HS PE is characterized in that being used for the distributed electric melting pipe fittings of wire spiral varying pitch.