PHOSPHINATED POLY(2,6-DIMETHYL PHENYLENE OXIDE) OLIGOMERS AND THERMOSETS THEREOF

Abstract

The present invention relates to a phosphinated poly(2,6-dimethy phenylene oxide)oligomer, specifically an unsaturated group-containing phosphinated poly(2,6-dimethy phenylene oxide)oligomer, and processes for producing the same. A thermoset produced from the unsaturated group-containing phosphinated poly(2,6-dimethy phenylene oxide)oligomers according to the present invention exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high glass transition temperature.

Claims

1. A phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (2): ##STR00044## wherein each group has the following meaning: P.sup.1 denotes ##STR00045## or does not exist; P.sup.2 denotes ##STR00046## R.sub.1, R.sub.2, R.sub.3 each independently denotes H or a straight chain or branched chain alkyl having 1 to 6 C-atoms; R.sub.4 denotes H, alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms, or the combination thereof; and m, n each independently denotes an integer from 0 to 30.

2. The oligomer according to claim 1, wherein at least the oligomer of formula (2) comprises a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3): ##STR00047## wherein P.sup.1, P.sup.2, R.sub.1, R.sub.2, R.sub.3 m, and n are as defined in claim 1.

3. The oligomer according to claim 2, wherein at least the oligomer of formula (3) comprises a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (IIa) or (IIc): ##STR00048## wherein R.sub.1, R.sub.2, R.sub.3, m, and n are defined in claim 1.

4. The oligomer according to claim 3, wherein at least the oligomer of formula (IIc) comprises a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (IIc): ##STR00049## wherein R.sub.1, R.sub.3, m, and n are as defined in claim 1.

5. The oligomer according to claim 1, wherein at least the oligomer of formula (2) comprises an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (4): ##STR00050## wherein P.sup.1, P.sup.2, R.sub.1, R.sub.2, R.sub.3, m and n are as defined in claim 1; and R.sub.4 denotes an alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms or the combination thereof.

6. The oligomer according to claim 5, wherein R.sub.4 denotes ##STR00051##

7. The oligomer according to claim 5, wherein at least the oligomer of formula (4) comprises an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIa) or (IIIc), ##STR00052## wherein R.sub.1, R.sub.2, R.sub.3, m and n are as defined in claim 1, and R.sub.4 denotes ##STR00053##

8. The oligomer according to claim 7, wherein at least the oligomer of formula (IIIc) comprises an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIc): ##STR00054## wherein R.sub.1, R.sub.3, m, and n are as defined in claim 1, and R.sub.4 denotes ##STR00055##

9. The oligomer according to claim 1, wherein R.sub.1, R.sub.2, or R.sub.3 each independently denotes H, CH.sub.3, or C.sub.2H.sub.5, and m or n each independently denotes an integer from 0 to 20.

10. The oligomer according to claim 5, wherein at least the oligomer of formula (4) comprises an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIc-M), (IIIc-A) or (IIIc-VB): ##STR00056## wherein m and n are as defined in claim 1.

11. A process for producing an oligomer of formula (3) set forth in to claim 2, comprising a reaction of compound of formula (I): ##STR00057## with poly(2,6-dimethyl phenylene oxide) under the catalysis of CuCl and an amine compound to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3) set forth in claim 3, wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in claim 1.

12. The process according to claim 11, wherein the amine compound comprises dibutylamine or 4-dimethylaminopyridine.

13. The process according to claim 11, wherein the produced phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (3) comprises at least an oligomer of formula (IIa) set forth in claim 3 or an oligomer of formula (IIc) set forth in claim 4.

14. A process for preparing an oligomer of formula (3) set forth in claim 2, comprising conducting a redistribution reaction for a compound of formula (I): ##STR00058## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in claim 1; and a poly(2,6-dimethyl phenylene oxide)oligomer of formula (5): ##STR00059## wherein Y denotes ##STR00060## and p, q each independently denotes an integer from 0 to 50; under the catalysis of a benzoyl peroxide to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3) set forth in claim 2.

15. The process according to claim 14, wherein the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3) comprises at least an oligomer of formula (IIc) set forth in claim 3.

16. A process for producing a compound of formula (4) set forth in claim 5, comprising reacting a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3) set forth in claim 2 with methacrylic anhydride, allyl bromine, or 4-chloromethylstyrene under the catalysis of a alkali catalyst to produce an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (4).

17. The process according to claim 16, wherein the phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (3) comprises an oligomer of formula (IIc) set forth in claim 3.

18. The process according to claim 16, wherein the alkali catalyst is selected from the group consisting of potassium carbonate (K.sub.2CO.sub.3), sodium carbonate (Na.sub.2CO.sub.3), potassium hydroxide (KOH), sodium hydroxide (NaOH), sodium bicarbonate (NaHCO.sub.3), or the combination thereof.

19. The process according to claim 16, wherein the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (4) comprises an oligomer of formula (IIa) or (IIIc) set forth in claim 7.

20. The process according to claim 19, wherein the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (4) comprises an oligomer of formula (IIIc-M), (IIIc-A), or (IIIc-VB) set forth in claim 10.

21. A thermoset produced from curing an oligomer of formula (4) set forth in claim 5 with a radical initiator.

22. The thermoset according to claim 21, wherein the oligomer of formula (4) set forth in claim 5 comprises an oligomer of formula (IIIc-M), (IIIc-A), or (IIIc-VB) set forth in claim 10.

23. The thermoset according to claim 21, wherein the radical initiator comprises a peroxide.

24. The thermoset according to claim 21, therein the radical initiator comprises t-butyl cumyl peroxide (TBCP).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 shows a .sup.1H-NMR spectrum of synthesized phosphinated methylphenol.

[0017] FIG. 2 shows an LC/MS spectrum of an oligomer of formula (IIa).

[0018] FIG. 3 shows an overlapping .sup.1H-NMR spectrum of oligomers of formulae (IIc) and (IIIc-VB).

[0019] FIG. 4 shows a DMA profile of a thermoset produced by curing an oligomer of formula (IIIc-VB) with an initiator of t-butyl cumyl peroxide (TBCP).

[0020] FIG. 5 shows a TMA profile of a thermoset produced by curing an oligomer of formula (IIIc-VB) with an initiator of t-butyl cumyl peroxide (TBCP).

[0021] FIG. 6 shows an ellipsometry measurement result of a thermoset produced by curing an oligomer of formula (IIIc-VB) with an initiator of t-butyl cumyl peroxide (TBCP).

DETAILED DESCRIPTION OF THE INVENTION

Phosphinated poly(2,6-dimethyl phenylene oxide)oligomers

[0022] The phosphinated poly(2,6-dimethyl phenylene oxide)oligomer according to the present invention comprises a structure of formula (2):

##STR00002##

wherein each group has the following meaning: [0023] P.sup.1 denotes

##STR00003## or does not exist; [0024] P.sup.2 denotes

##STR00004## [0025] R.sub.1, R.sub.2, R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl; [0026] R.sub.4 denotes H, alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms, or the combination thereof, preferably

##STR00005## [0027] m, n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

Phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomers

[0028] In a phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of the present invention, when R.sup.4 is H, the oligomer of formula (2) is a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer. In addition, at least an oligomer of formula (2) is represented by formula (3):

##STR00006##

wherein each group has the following meaning: [0029] P.sup.1 denotes

##STR00007## or does not exist; [0030] P.sup.2 denotes

##STR00008## [0031] R.sub.1, R.sub.2, R.sub.3 each independently denotes H, or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl; [0032] m, n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0033] In an embodiment of the present invention, at least an oligomer of formula (3) is represented by formula (IIa) or formula (IIc):

##STR00009##

wherein each group has the following meaning: [0034] R.sub.1, R.sub.2, R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl; [0035] m, n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0036] In an embodiment of the present invention, formula (IIa) preferably is:

##STR00010##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.3 is H or CH.sub.3.

[0037] In an embodiment of the present invention, formula (IIc) preferably is:

##STR00011##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.2 is H or CH.sub.3, and R.sub.3 is H or CH.sub.3; or

##STR00012##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.3 is H or CH.sub.3.

Unsaturated Group-Containing Phosphinated Poly(2,6-dimethyl phenylene oxide)oligomers

[0038] In a phosphinated poly(2,6-dimethyl phenylene oxide)oligomer according to the present invention, when R.sup.4 is not H, the oligomer of formula (2) is directed to an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer, wherein at least an oligomer of formula (2) is represented by formula (4):

##STR00013##

wherein each group has the following meaning: [0039] P.sup.1 denotes

##STR00014## or does not exist; [0040] P.sup.2 denotes

##STR00015## [0041] R.sub.1, R.sub.2, R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl; [0042] R.sub.4 denotes H, alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms, or the combination thereof, preferably

##STR00016## [0043] m, n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0044] In an embodiment of the present invention, at least an oligomer of formula (4) is represented by formula (IIIa) or (IIIc):

##STR00017##

wherein each group has the following meaning: [0045] R.sub.1, R.sub.2, R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl; [0046] R.sub.4 denotes H, alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms, or the combination thereof, preferably is

##STR00018## [0047] m, n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0048] In an embodiment of the present invention, formula (IIIa) preferably is:

##STR00019##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00020##

[0049] In an embodiment of the present invention, formula (IIIc) preferably is:

##STR00021##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.2 is H or CH.sub.3, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00022##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00023##

[0050] In an embodiment of the present invention, the oligomer of formula (4) comprises an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer of formula (IIIc-M), (IIIc-A), or (IIIc-VB).

##STR00024##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.
Process for Producing a Phosphinated Poly(2,6-dimethyl phenylene oxide)bisphenol oligomer

[0051] In the process for producing an oligomer according to the invention, the phosphinated bisphenol compound of formula (I) is first synthesized by way of the following scheme:

##STR00025##

wherein R.sub.1, R.sub.2 or R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl. Then, the bisphenol compound of formula (I) is reacted with 2,6-dimethylphenol under the catalysis of CuCl and an amine compound, such as dibutylamine (DBA) or 4-dimethylaminopyridine (DMAP), to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer.

[0052] In an embodiment of the present invention, the process for producing a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer of formula (2) includes reacting the compound of formula (I) with 2,6-dimethylphenol under the catalysis of CuCl and an amine compound, such as dibutylamine or 4-dimethylaminopyridine, to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer, wherein R.sub.1 or R.sub.2 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl, or ethyl.

[0053] In the process for producing an oligomer according to the present invention, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises at least an oligomer of formula (3).

[0054] Specifically, in the process for producing an oligomer according to the present invention, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises at least an oligomer of formula (IIa) or (IIc).

[0055] In the process for producing an oligomer according to the present invention, when R.sub.2 is H, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises an oligomer of formula (IIa):

##STR00026##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.3 is H or CH.sub.3.

[0056] In the process for producing an oligomer according to the present invention, when R.sub.2 is CH.sub.3, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises an oligomer of formula (IIc):

##STR00027##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.3 is H or CH.sub.3.

[0057] One method for producing bisphenol group-containing PPO is by way of a redistribution reaction associated with bisphenol and high molecular weight PPO. However, the redistribution reaction usually produces a product having bimodal molecular weight distribution due to the occurrence of a side reaction. Because of the poor solubility and impregnation of the high molecular weight product, the application in a copper foil substrate is thus restricted. Quite different from the conventional technique, the present invention utilizes a PPO oligomer, such as SABIC SA-90, as a starting material to conduct a redistribution reaction for phosphinated diphenol and SA-90 to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer that exhibits improved solubility and impregnation to glass fiber and exhibits flame retardancy.

[0058] According to an embodiment of the present invention, the process for producing an oligomer includes conducting a redistribution reaction for the compound of formula (I) and a poly(2,6-dimethyl phenylene oxide)oligomer of formula (5):

##STR00028##

under the catalysis of a benzoyl peroxide to produce a phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer, wherein [0059] Y denotes

##STR00029## and [0060] p, q each independently denotes an integer from 0 to 50.

[0061] According to an embodiment of the present invention, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises at least an oligomer of formula (3).

[0062] Specifically, in the process for producing an oligomer according to the invention, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises at least an oligomer of formula (IIc).

[0063] In the process for producing an oligomer according to the invention, the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer comprises an oligomer of formula (IIc):

##STR00030##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.2 is H or CH.sub.3, and R.sub.3 is H or CH.sub.3.
Process for Producing an Unsaturated Group-Containing Phosphinated Poly(2,6-Dimethyl phenylene oxide)oligomer

[0064] The process for producing an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer includes reacting the end-capping hydroxyl group of the produced phosphinated poly(2,6-dimethyl phenylene oxide)bisphenol oligomer with methacrylic anhydride, allyl bromine, or 4-chloromethylstyrene under the catalysis of a alkali catalyst to produce an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer.

[0065] According to an embodiment of the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer comprises at least an oligomer of formula (4).

[0066] Specifically, according to an embodiment of the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer comprises at least an oligomer of formula (IIIa) or (IIIc):

##STR00031##

wherein R.sub.1, R.sub.2 or R.sub.3 each independently denotes H or straight chain or branched chain alkyl having 1 to 6 C-atoms, preferably H, methyl or ethyl, and R.sub.4 denotes H, alkenyl or aryl having 1 to 10 C-atoms and comprising 0 to 3 oxygen atoms, or the combination thereof, preferably

##STR00032##

[0067] Specifically, according to an embodiment of the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer comprises at least an oligomer of formula (IIIa):

##STR00033##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00034##

[0068] According to an embodiment of the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer comprises an oligomer of formula (IIIc) or (IIIc):

##STR00035##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.2 is H or CH.sub.3, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00036##

wherein R.sub.1 is H, CH.sub.3, or C.sub.2H.sub.5, R.sub.3 is H or CH.sub.3, and R.sub.4 is

##STR00037##

[0069] In the process for producing an oligomer according to the present invention, the alkali catalyst is selected from the group consisting of potassium carbonate (K.sub.2CO.sub.3), sodium carbonate (Na.sub.2CO.sub.3), potassium hydroxide (KOH), sodium hydroxide (NaOH), sodium bicarbonate (NaHCO.sub.3), or the combination thereof.

[0070] In the process for producing an oligomer according to the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer is represented by formula (IIIc-M):

##STR00038##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0071] In the process for producing an oligomer according to the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer is represented by formula (IIIc-A):

##STR00039##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0072] In the process for producing an oligomer according to the present invention, the produced unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide) oligomer is represented by formula (IIIc-VB):

##STR00040##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.
Thermoset Produced from an Unsaturated Group-Containing Phosphinated Poly(2,6-Dimethyl Phenylene Oxide)Oligomer and the Process for Producing the Same

[0073] An unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (4) is subjected to an unsaturated group reaction by using a peroxide as a radical initiator to produce a thermoset that exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high-Tg.

[0074] In the process for producing a thermoset according to the invention, an oligomer of formula (4) is cured by using a radical initiator to produce a thermoset that exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high-Tg.

[0075] In the process for producing a thermoset according to the invention, the radical initiator comprises a peroxide, preferably t-butyl cumyl peroxide (TBCP).

[0076] In the process for producing a thermoset according to the invention, an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIc-M) is cured by using a radical initiator, such as t-butyl cumyl peroxide (TBCP), to produce a thermoset that exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high-Tg.

[0077] In the process for producing a thermoset according to the invention, an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIc-A) is cured by using a radical initiator, such as t-butyl cumyl peroxide (TBCP), to produce a thermoset that exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high-Tg.

[0078] In the process for producing a thermoset according to the invention, an unsaturated group-containing phosphinated poly(2,6-dimethyl phenylene oxide)oligomer of formula (IIIc-VB) is cured by using a radical initiator, such as t-butyl cumyl peroxide (TBCP), to produce a thermoset that exhibits flame retardancy and has a low dielectric constant and dissipation factor and a high-Tg.

EXAMPLE

[0079] The inventions are demonstrated and illustrated in the following working examples.

[0080] While the following description contains many specifics, these specifics should not be construed as limitations to the scope of the inventions, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the inventions as defined by the claims appended hereto.

Example 1

Synthesis of Phosphinated Methylphenol

[0081] 10.0 g (73.4 mmol) p-hydroxyacetophenone, 15.9 g (73.4 mmol) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 44.40 g (73.45 mmol) 2,6-dimethylphenol, and 0.64 g p-toluenesulfonic acid (i.e. 4 wt % of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) were reacted under a nitrogen atmosphere at 130 C. for 24 hours. After the reaction was terminated, the product was filtered at an elevated temperature to obtain a filtered cake. The white powder was obtained by using methanol to rinse the filtered cake several times. After suction filtration, the white powder was dried in a vacuum oven at a temperature of 80 C. The yield was about 85%.

[0082] FIG. 1 shows a .sup.1H NMR spectrum of monomer of the synthesized phosphinated methylphenol. It can be found that the characteristic peak of CH.sub.3(a) is at 1.6 ppm, the characteristic peak of CH.sub.3(b) is at 2.0 ppm, and the characteristic peak of ArOH is at 9.4 ppm. In addition, a peak at 38.0 ppm can be found in the .sup.31P NMR spectrum. It was confirmed that the resulting structure is correct.

Example 2

Synthesis of Phosphinated Methyl Polyphenylene Oligomer of Formula (IIa)

[0083] 0.079 g (0.8 mmole) CuCl and 0.095 g (0.78 mmole) DMAP were dissolved in a 1-methyl-2-pyrrolidone (NMP) solvent of 25 mL. After injecting oxygen gas for 10 mins at room temperature, 0.739 g (1.62 mmole) of monomer (1) and 0.979 g (8.01 mmole) 2,6-dimethylphenol were added to the solution. Under an oxygen atmosphere, the reaction was conducted at a temperature of 40 C. for 4 hours. After the reaction was terminated, a filtrate was obtained through suction filtration. The product was precipitated by adding methanol to the filtrate and was then rinsed several times. After a second suction filtration, the filtered cake was dried in a vacuum oven at a temperature of 80 C. to produce a khaki product IIa. FIG. 2 shows an LC/MS spectrum of the product IIa. The peak of 697.5 m/z corresponds to the molecular weight of n=1. The molecular structure of n=2 to n=11 can also be found in FIG. 2.

Example 3

Synthesis of Phosphinated Methyl Polyphenylene Oxide of Formula (IIc)

[0084] 4.0 g (8.76 mmol) phosphinated methylphenol produced in Example 1 and 4 g (8.763.8 mmol) SABIC SA-90, and 0.404 g ( 1/40 mol of SA-90) benzoyl peroxide were dissolved in an NMP solvent and reacted under a nitrogen atmosphere at a temperature of 130 C. for 12 hours. After the reaction was terminated, a brown powder was precipitated by using methanol/water and was then rinsed several times. After suction filtration, the filtered cake was dried in a vacuum oven at a temperature of 70 C. The yield was about 90%. The .sup.1H NMR spectrum shows that the peak(s) around 6 to 8.5 ppm correspond(s) to the hydrogen signal originating from diphenyl of the biphenylene phosphinate structure. The GPC data (using tetrahydrofuran (THF) as an eluent and polystyrene as a standard) reveals that the number-average molecular weight and weight-average molecular weight of SA-90 are 1,508 and 3,978 g/mol, respectively. The number-average molecular weight and weight-average molecular weight of the oligomer of formula (IIIc) are 787 and 2,625 g/mole, respectively. The above results confirm that after conducting the redistribution reaction, the average molecular weight tends to be reduced, and this is advantageous for improving the solubility and impregnation.

Example 4

Synthesis of Methacrylated (MMA) Phosphinated Ethylpolyphenylene Oxide of formula (IIIc-M)

[0085] 1.0 g of the oligomers of formula (IIc) synthesized in Example 3 and 0.01 g (2 mol % of methacrylic anhydride) DMAP were dissolved in a dimethylacetamide (DMAc) solvent of 15 mL and were reacted under an argon atmosphere at room temperature for 1 hour. Then, 0.665 g methacrylic anhydride was added and reacted at room temperature for 3 hours and subsequently at a temperature of 45 C. for 24 hours. After the reaction was terminated, the product was precipitated using a saturated NaHCO.sub.3 solution (to remove the acid) and was rinsed with water several times. After suction filtration, the filtered cake was dried in a vacuum oven at a temperature of 50 C. The yield was about 85%. The Fourier transform infrared spectroscopy (FTIR) analysis result shows that the characteristic peak of OCO is at 1735 cm.sup.1, and the characteristic peak of CC is at 1649 cm.sup.1. The produced methacrylated (MMA) phosphinated ethylpolyphenylene oxide is represented by the following formula:

##STR00041##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0086] The characteristic peaks of 2.0, 5.9, and 6.3 ppm shown in the .sup.1H NMR spectrum of the oligomer of formula (IIIc-M) correspond to an acrylate group. The above result confirms that the resulting molecular structure is correct.

Example 5

Synthesis of Allylated Phosphinated Ethyl Polyphenylene Oxide of Formula (IIIc-A)

[0087] 1.0 g of the oligomers of formula (IIc) synthesized in Example 3, 0.23 g allyl bromine, and 0.1 g K.sub.2CO.sub.3 were dissolved in a DMAc solvent of 15 mL and were reacted under a nitrogen atmosphere at an elevated temperature of 65 C. for 24 hours. After the reaction was terminated, the temperature was cooled to room temperature. The salts were filtered out to collecting the filtrate. The filtrate was added to an iced saturated brine. After suction filtration, the filtered cake was dried in a vacuum oven at a temperature of 60 C. to produce a slightly sticky khaki solid product. The yield was about 70%. The FTIR result shows a characteristic peak of an allyl group at 915 cm.sup.1. The produced allylated phosphinated ethyl polyphenylene oxide is represented by the following formula:

##STR00042##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0088] The characteristic peaks of 4.8, 5.3, and 6.1 ppm shown in the .sup.1H NMR spectrum of the oligomer of formula (IIIc-A) correspond to an allyl group. The above result confirms that the resulting molecular structure is correct.

Example 6

Synthesis of Vinylbenzylated Phosphinated Ethyl Polyphenylene Oxide of Formula (IIIc-VB)

[0089] 1.0 g of the oligomers of formula (IIc) synthesized in Example 3, 1.4 g 4-chloromethylstyrene, and 0.1 g K.sub.2CO.sub.3 were dissolved in a DMAc solvent of 15 mL and were reacted under a nitrogen atmosphere at a temperature of 120 C. for 12 hours. After the reaction was terminated, a khaki powder was precipitated by using ethanol and was rinsed several times. After suction filtration, the filtered cake was dried in a vacuum oven at a temperature of 80 C. The yield was about 88%. The produced vinylbenzylated phosphinated ethyl polyphenylene oxide is represented by the following formula:

##STR00043##

wherein m or n each independently denotes an integer from 0 to 30, preferably an integer from 0 to 20.

[0090] FIG. 3 shows a .sup.1H NMR spectrum of the oligomers of formulae (IIc) and (IIIc-VB). It can be found in FIG. 3 that the peak(s) related to an OH functional group of the oligomer of formula (IIc) (4.3-4.6 ppm) disappeared, and the characteristic peaks of a 4-chloromethylstyrene structure of the oligomer of formula (IIIc-VB) are present at 5.2 (CH, marked as 1), 5.8 (CH.sub.1, marked as 1), and 4.8 (CH.sub.2, marked as 3).

Example 7

Synthesis and Characterization of a Thermoset Produced from Methacrylated (MMA) Phosphinated Ethylpolyphenylene Oxide of Formula (IIIc-M)

[0091] 1.0 g of the oligomers of formula (IIIc-M) synthesized in Example 4 were dissolved in an NMP solvent to produce a solution having 30 wt % solid content. After complete dissolution, a free-radical reaction was conducted by adding 1 wt % t-butyl cumyl peroxide (TBCP) to produce a film. The film was dried in a circulation oven at a temperature of 110 C. for 12 hours to remove most of the solvent. Then, the temperature was elevated to 180 C., 200 C., and 220 C. and maintained at each step temperature for 2 hours. Finally, a phenol film was produced by dipping the glass substrate in water and was then analyzed to obtain its thermal properties. The dynamic mechanical analysis (DMA) result of the produced thermoset is shown in FIG. 4, where the Tg of the produced thermoset is determined to be 277 C. Regarding the dielectric constant (Dk), the refractive index (n) was measured to be 1.55 by ellipsometry using an incident wavelength of 633 nm According to the equation Dk=1.1 n.sup.2, the dielectric constant of the thermoset produced from the oligomers of formula (IIIc-M) can be computed as 2.64 (U), which reveals that the produced thermoset has a relatively low dielectric constant.

Example 8

Synthesis and Characterization of the Thermoset Produced from Allylated Phosphinated Ethylpolyphenylene Oxide of Formula (IIIc-A)

[0092] 1.0 g of the oligomers of formula (IIIc-A) synthesized in Example 5 were dissolved in an NMP solvent to produce a solution having 30 wt % solid content. After complete dissolution, a free-radical reaction was conducted by adding 1 wt % t-butyl cumyl peroxide (TBCP) to produce a film. The film was dried in a circulation oven at a temperature of 110 C. for 12 hours to remove most of the solvent. Then, the temperature was elevated to 180 C., 200 C., and 220 C. and maintained at each step temperature for 2 hours. Finally, a phenol film was produced by dipping the glass substrate in water and was then analyzed to obtain its thermal properties. The dynamic mechanical analysis (DMA) result shows that the Tg of the produced thermoset is 294 C. Regarding the dielectric constant (Dk), the refractive index (n) was measured to be 1.59 by ellipsometry using an incident wavelength of 633 nm According to the equation Dk=1.1 n.sup.2, the dielectric constant of the thermoset produced from the oligomers of formula (IIIc-A) can be computed as 2.78 (U).

Example 9

Synthesis and Characterization of the Thermoset Produced from Vinylbenzylated Phosphinated Ethyl Polyphenylene Oxide of Formula (IIIc-VB)

[0093] 1.0 g of the oligomers of formula (IIIc-VB) synthesized in Example 6 were dissolved in an NMP solvent to produce a solution having 30 wt % solid content. After complete dissolution, a free-radical reaction was conducted by adding 1 wt % t-butyl cumyl peroxide (TBCP) to produce a film. The film was dried in a circulation oven at a temperature of 110 C. for 12 hours to remove most of the solvent. Then, the temperature was elevated to 180 C., 200 C., and 220 C. and maintained at each step temperature for 2 hours. Finally, a phenol film was produced by dipping the glass substrate in water and was then analyzed to obtain its thermal properties. The dynamic mechanical analysis (DMA) result of the produced thermoset is shown in FIG. 4, where the Tg of the produced thermoset was determined to be 314 C. In addition, the thermomechanical analysis (TMA) shown in FIG. 5 reveals that the Tg of the produced thermoset was measured to be 302 C. The above results confirm that the thermoset of the present invention exhibits superior thermal properties. Regarding the dielectric constant (Dk), the refractive index (n) was measured to be 1.50 by ellipsometry using an incident wavelength of 633 nm According to the equation Dk=1.1 n.sup.2, the dielectric constant of the thermoset produced from the oligomers of formula (IIIc-VB) can be computed as 2.48 (U), which reveals that the produced thermoset has a relatively low dielectric constant, as shown in FIG. 6.