CS270317B1 - Composite materials - Google Patents

Abstract

Mixtures of polyalkenes with mineral fillers have very good fluidity when they contain 1 to 15% by weight of modified polyalkenes of the general formula I R 1 R| R j -Cil -<--- Cil -C- Cl. -c. 1 >’'J rn 1 X 1 r; Y where m + n is 5o to 1 ooo, R.R' Is 11, Cll3, C2II5, CJlg, HjC - Cil - , X Is fH3 /fH3 -Si -O -l Si - o CH3 ' γ^Η3 CH \ 1 3 k V Si éH3 or [CH2<O)CH2 ' k k is O or 1 Y Is [° (CH2>a]p - H • C S 2 7 o 3 1 7 B l where a Is 1 to 4, p is 5 to 5o or - O <řH3 Si _ O CH. Jb - H where b is 3 to 4 o.

Description

The invention relates to the possibility of using amphilytic copolymers for easier processing of composites of polyalkenes with mineral fillers.

Mixtures of large-scale polymers with mineral fillers (talc, kaolin, calcium carbonate, magnesium hydroxide, partially dehydrated aluminum hydroxide, titanium dioxide, glass) are gaining increasing importance among construction materials.

Composites with organic fillers, such as carbon black, natural and artificial fibers (including carbon), etc., are also of great importance. In addition to the filler, the composites also contain thermo-oxidative and photo-oxidative stabilizers, dyes and additives improving processing and application properties (plasticizers). It is advantageous to use copolymers formed by hydrophobic and hydrophilic polymer chains in the preparation of composites of polyalkenes with mineral fillers, which can ensure the compatibility of individual, mostly mutually incompatible components, as described in the author's certificate No. 263 262. The mutual incompatibility of the polymer and the filler is caused by the fact that the Van der Waals forces between the molecules of individual polymers (polymer - polymer) and fillers (filler - filler) are much greater than the attractive forces between the molecules of the polymer and the filler (polymer - filler). In composites of polyalkenes with mineral fillers, the compatibility problem is usually solved by treating the filler (etharic acid and its salts, silane). This treatment consists in creating a shell around the filler particles that has an affinity for the filler 1 polymer. More promising than treatment is the addition of a copolymer (e.g. polyalken-block (graft) polyacrylates, polyalken - block (graft) polyether. polyalken - block (graft) polyacrylic acid, etc.). Treatment with a copolymer also dampens the mechanical stress between the polymer and the filler, leading to the formation of microcracks, defects, and as a result to the loss of mechanical strength of the composite, and causes a more complete dispersion of the filler in the matrix.

The particularly elastic nature of the copolymer blocks or grafts ensures more effective amortization of interfacial tension. As a result, the mechanical properties of the composites are improved.

The addition of an amphiphilic copolymer, having affinity for all components of the composite, will not only ensure the compatibility of the system and improve some mechanical properties (especially notch and impact toughness), but can also significantly facilitate the processing of the composite. Copolymers containing blocks or grafts that melt at a lower temperature than the other component of the copolymer (crystalline polyalkene) or have elastomeric character (polysiloxanes) can effectively reduce the melt viscosity of the processed composite.

Processing well-flowing mixtures also results in significant energy savings, which significantly streamlines the entire production process.

It has now been found that, in particular, copolymers of polypropylene with polyethylene oxide, polypropylene oxide, polytetrahydrofuran, polyoxetane and poly(dimethylsiloxane) formed by low molecular weight blocks and/or grafts, i.e. segments and with a degree of polymerization of PP - 10 to 1000 and of the modifying component 3 to 50, not only have the desired compatibilizing effects, but also significantly reduce the viscosity of the melt. To facilitate processability (ensuring higher ITT values), it is therefore desirable that the amphiphilic copolymer contained in the composite (1 to 5% by weight) be formed by shorter blocks and/or grafts than the polymer matrix chains.

The subject of the invention are composite materials formed from a mixture of polyalkenes with mineral fillers and modified polyalkenes, which contain 1 to 15% by weight of modified polyalkenes of the general formula:

CS 27o317 = 1 where m or ^CH 2 ^CH 2 + n is 5o to 1 ooo,

CH, I 3

^SiCH3

^CH 2 ch ₂

R, R is ^CH3

Si ^CH 3 ch ₃ , c ₂ h ₅ ,

4’ 9’ 2

CH where k · O or (CH ₂ ) _a - HJP where a

It is up to 4, p is 5 to 5o or bo ^3

Si - O ^CH 3 where b to 4o

The synthesis of suitable amphiphilic copolymers of polyacrylamides is very demanding in terms of experimental design and can only be carried out in an environment that completely prevents contamination of ionic or coordination active centers (in high-vacuum apparatus in an inert gas atmosphere). The first syntheses have been carried out only recently and are based on reactions associated with the transformation of coordination active centers into ionic or radical centers (e.g. Richards, D. D. Br. Polym. J. 12, 89 (198o) or cationic modifications of polyalkenes (see author's certificates No. 19o 127, 22o 722, No. 238 24ο, No. 24o 627, No. 248 854). The melt of these copolymers acts as a lubricant during the processing of composites, the mixture flows better into the molds. In this case, the segments with heteroatoms or polar groups are bound to the polyalkene chain by covalent bonds, so they cannot be displaced from the composite.

The invention will be further illustrated by the following examples, % and parts in the examples are by weight.

Example 1

The following components (total 70 g) were mixed in a Plasticorder Brabender laboratory mixer at 403/2 for 10 min: polypropylene (PP) Mosten 55 212 stabilized with thermo- and photo-oxidation stabilizers (60%) + 40% CaCO^ Durcal 2, modified with 0.3% stearic acid and 0.5% calcium stearate. In this way, a comparative composite was prepared.

Example 2

The procedure was as in example 1, but the following components were kneaded: PP Mosten 55 212 (55%), 40% untreated CaCO ₃ (Durcal 2), 5 copolymers of polypropylene with polyethylene oxide (PEOX) blocks or grafts (composition of copolymers - 5% PP with a degree of polymerization of 50 to

CS 27o317 Bl ooo, 95% PEOX and 5 to 5o basic structural units in the chains - connecting group X - Si(Me) ₂ - O Sl(Me) ₂ ] ₅ - O - Si(Me) ₂ ~.

Example 3

Procedure As in example 1, composite composition t PP Mosten 55 212 (58%) + 40% untreated CaCO^ Durcal 2 + 2% copolymers As in example 2.

Attached

Proceeding according to example 1, the components were mixed: 55% PP Mosten 55 212 + 40¾ micronized limestone Durcal 2 + 5% terpolymer PP, PEOX and polyoxytetramethylene (PTHF), molar ratio of polyethers -1:1 (M^ PEOX - 2oo to 2'ooo; M _n PTHF - 35o to 3 5oo; M _n PP - 4oo to 8 ooo). Ratio PP : polyethers - 5 : 95.

Example 5

Procedure As in Example 1, composite components t 58% PP Mosten 552 212, 40% CaCO^ Durcal 2 - untreated, 2% copolymers As in Example 4.

Examples

Procedure according to example 1, composition of composites: PP Mosten 58 412 (55%) + 40% untreated CaCO^ + 5% terpolymer according to example 4.

Example 7

Proceeded as in example 1, the components were mixed: 58% PP Mosten 5 842 + 40% untreated Durcal 2 + 2% copolymers as in example 4.

Example 8

Procedure and weight proportions As in Example 4, but the polymer matrix was PP Mosten 52 815.

Example 9

Procedure and weight proportions As in Example 5, but the polymer matrix was PP Mosten 52 815.

Example 10

The procedure and weight proportions are the same as in Example 4, but the polymer matrix was PP Mosten 52 511.

Example 11

Procedure and weight ratio of the composite composition As in example 5, polymer used - PP Mosten 52 517;

Test specimens were molded from the composites described in Examples 1 to 11 and the melt flow indices (ITT, g/l0 min.) were measured using standard tests. The ITT of the polypropylene matrices used are also given in the table for comparison.

Component V in copolymers has the melting point of polyethers [poly(oxytetramethylene), poly(oxyethylene), poly(oxy 1-methylethylene)], i.e. 43 to 45 °C, or has the character of a viscous liquid poly(siloxanes). When the composite is processed at higher temperatures, component Y melts and acts as a non-migrating lubricant.

The influence of copolymers reduces the melt viscosity of the composite and improves flowability. The effect of copolymers was tested in various polyalkene matrices, in all cases the viscosity increases and the ITT of the composite increases. The mechanical properties of blends with copolymers correspond to the co-position

4 CS 27o317 Bl ts with a certain content of EPDM rubber (higher toughness), ITT and Vicat heat resistance values It is even superior (see author's certificate 263 262). PP matrix Composite composition (weight ratio Example ITT ITT matrix: filler: copolymer) 49 N Mosten loo : O : O o.57 2.59 55 212 6o : 4o upr. : O 1 o.66 2.97 M Mosten 55 : 4o neupr. : 5 2 6.24 23.3o 55 212 (PP - PEOX copolymer) X Mosten 58 t 4o neupr. : 2 3 1.13 5.o9 55 212 (PP - PEOX copolymer) m —— m»·· — — — —i» — — W— — WM —— «we —— — — ae — ee — M» — aeM — M — »ee«w·· —— Mosten 55 : 4o neupr. : 5 . 4 9.97 38.48 55 212 (terpolymer PP-PEOX-PTHF) Mosten 58 : 4o : 2 5 1.18 5.11 55 212 (terpolymer PP-PEOX-PTHF) Mosten 55 : 4o neupr. : 5 terpol. 6 6.o3 35.21 58 212 58 : 4o not adjusted : 2 t/half 7 4.74 Mosten loo : O : O · 11.34 59.2o 52 B15 55 : 4o not adjusted : 5 terpol. 8 1.35 50 : 4o not adjusted : 2 terpol. 9 17.95 Mosten loo : O : O 5.34 16.13 52 511 55 : 4o unadjusted : 5 terpol. lo 8.61 Mosten loo : O : O 4.82 . * 52 517 58 : 4o : 2 11 8.94 Example 12 If . Procedure As in Examples 2 and 3, but instead of polypropylene-block, (graft) poly (oxyethylene) polypropylene-block, graft poly(oxypropylene) was used. (M _n PP - 4oo to 8oo; polyoxypropylene - 275 to 3 ooo). Ratio PP : PPOX . 5 : 95. Example 13 Procedure As in Examples 2 and 3, but the copolymer used was a tactic polypropylene modified with polyoxyethylene. Degree of polymerization a - PP - lo to loo, degree of polymerization of polyethylene oxide and PTHF - 5 to 5o.

CS 27o317 Bl 5

Example 14

The procedure was as in example 1, but the composition of the composite was: 56% polyethylene FB29 + 40% untreated micro-ground CaCO^ (Durcal 2) + 4% copolymer polypropylene — co — ethylene) blocks and grafts of PEOX and PTHF, Mn PP - co - PE “ 35o to 7 ooof Mn PEOX 2oo to 2 4ooí Mn PTHF - 35o to 3 5oo.

Example 15 ·

The procedure was as in Examples 2 to 14, but the amount of copolymer added was:

15/1 - 1%, 15/2 - 3%, 15/3 - 7%, 15/4 - 10%, 15/5 15%. Composites with higher copolymer content (15/4 and 15/5) were difficult to process (rubbery character, adhesives, bubbles), their amount above 10% in composites is intended for special use.

Example 16.

The procedure is the same as in examples 2, 3, but the copolymer polypropylene - block, (graft) - polyoxetane was used. Μη PP 4oo to 8 oooi Mn polyoxetane - 3oo to 3 ooo, '

Did he give an example?

The procedure is as in Examples 2 and 3, but the copolymer used was Isotactic polypropylene modified with blocks and grafts of polydimethylsiloxane. Copolymer composition: Mn PP 4oo to 8oo, Mn PD - 2oo to 3oo. Ratio PP to PD 10 to 9o. Example 18

The procedure is as in Example 2, but the linking group X - -CH^^^- CH^ - is used, the type of linking group does not significantly affect the properties of the copolymer.

Claims (1)

Composite materials consisting of a mixture of polyalkenes and mineral fillers and modified polyalkenes, characterized in that they contain 1 to 15% by weight of modified polyalkenes of general