Graft copolymers of the polyester from allylphosphinic acid dichloride and diphenylolpropane with methylmethacrylate and styrene

Graft copolymers of t h e polyester

2337

9. C. I. K t ~ H t E , M. WALES and M. E. DOYLE, S P E J . 20: 1113, 1964 10. H. N. BECK and H. D. LEDBETTER, J. Appl. P o l y m e r Sci., 9, 2131, 1965 11. V. A. KARGIN, T. I. SOGOLOVA and I. I. KURBANOVA, Dokl. Akad. N a u k SSSR 162: 1092, 1965 12. V. A. KARGIN, T. I. SOGOLOVA a n d I. I. KURBANOVA, Vysokomol. soyed. 7: 2108, 1965 (Translated in Polymer Science U.S.S.R. 7: 12, 2308, 1965) 13. V. A. KARGIN a n d T. I. SOGOLOVA, Zh. fiz. khimii 27: 1039, 1953 14. V . A . KARGIN, T. I. SOGOLOVA a n d T. K. SHAPOSHNIKOVA, Bold. Akad. 2ffauk SSSR 156: 1156, 1964 15. V. A. KARGIN, T. I. SOGOLOVA and N. Ya. RAPOPORT-MOLODTSOVA, Dokl. Akad. N a u k SSSR 163: 1194, 1965 16. V. A. KARGIN, T. I. SOGOLOVA a n d N. Ya. RAPOPORT-MOLODTSOVA, Vysokomol. soyed. 6: 2090, 1964 (Translated ha P o l y m e r Science U.S.S.R. 6: 11, 2318, 1964) 17. V. A. KARGIN, T. L SOGOLOVA a n d T. K. SHAPOSHNIKOVA, Vysokomol. soyed. 7: 229, 1965 (Translated in Polymer Science U.S.S.R. 7: 2, 250, 1965)

GRAFT COPOLYMERS OF THE POLYESTER FROM ALLYLPHOSPHINIC ACID DICHLORIDE AND DIPHENYLOLPROPANE WITH METHYLMETHACRYLATE AND STYRENE* M. F . SOROKII~" a n d I . Ma_nOWCHU D. I. Mendeleyev Moscow Chemical Technology I n s t i t u t e

(Received 27 September 1965) I ~ x study of the polycondensation reaction between allylphosphinic acid dichloride and diethyleneglycol, triethyleneglycol, and also with hydroquinone, resorcinol and 2,2-di-(4-hydroxyphenyl) propane (diane), we showed [1] t h a t linear polyesters are thus formed, which contain one allyl group in each elementary unit and have the following general formula:

o

]

--~--O--R--O-- , CH+--CH=CH2 J where R=CH~CHa--O--CH2CH2--; --CH2CH2--O--CH~CHz--O--CH,CH2--; CHs

* Vysokomol. soyed. 8: No. 12, 2112-2116, 1966.

2338

M.F.

So~oraN and

I. MA~o~nc,~u

We have investigated their capacity to form graft three-dimensional polymers. In the literature, there are data only about the transformation of linear polyesters containing phosphours into three-dimensional polymers by use of the vinyl double bonds located in the side chains [2-9]. The polyester (PE) synthesized by us from the acid dichloride of allyl-phosphinic acid and diane (in ditolyl methane at 200°C), having a molecular weight of 1340 (by ebulliometry) and a Ubbelohde drop fall temperature of 87°C, was selected for the investigation. The reason for the selection of this P E is that the P - - O - - C bond is stronger in aromatic polyesters than in aliphatic polyesters. Moreover, of the polymers obtained by us [1] by the reaction of the acid dichloride of allylphosphinic acid with bifunctional phenols, it had the greatest molecular weight and the highest drop fall temperature, as well as having the lightest colour. Experiments in the catalytic (heating at 80-120°C in the presence of benzoyl peroxide or of azobisisobutyronitrile) or oxidative (heating to 150°C in the presence of atmospheric oxygen) hardening of P E indicated that under these conditions polymerization at the allyl double bonds does not take place with the formation of a three-dimensional polymer. It is known that monomers of the allyl type polymerize with difficulty and form polymers with low molecular weights [10]. The reason for this is chain transfer as a result of reaction between the growing radical and the monomer. Taking this into account, one should expect that during the joint polymerization of P E with vinyl monomers the formation of three-dimensional copolymers should take place, the copolymers Containing phosphorus in the macromolecule. We used methylmethacrylate (MMA) and styrene as the vinyl monomer. The results of preliminary experiments (in ampoules in an atmosphere of nitrogen and in the presence of benzoyl peroxide, azobisisobutyronitrile, and tertiary butyl peroxide) indicated that P E contributes to the cross-linking of polymethylmethacrylate (PMMA) and polystyrene chains respectively. When the solution of P E in the monomer was heated, the specimens became more viscous and after a certain time, flow ceased. I n the same solvents in which P E and the corresponding homopolymers dissolved, the final products only swelled.Clearly not all the allyl double bonds take part in the formation of the three-dimensional structure of the crosslinked polymers, otherwise the products would probably have been very sensitive to the effect of the solvent. It turned out to be impossible to determine the concentration of double bonds in the copolymcrs quantitatively by the chemical method, since the copolymers were insoluble, but we demonstrated the presence of double bonds in the final copolymers qualitatively by the infrared spectroscopy method (absorption of the monosubstituted ethylene double bond (R)HC=CH~ at 1647 em -1. The copolymerization of P E with MMA or with styrene was carried out in a nitrogen atmosphere at 80°C in the presence of azobisisobutyronitrile (1 wt. ~/o,

Graft copolymers of the polyester

2339

calculated on t h e v i n y l m o n o m e r ) a n d w i t h weight ratios of P E : v i n y l m o n o mer, e q u a l t o 2 : 1, 1.5 : 1, 1 : 1, a n d 1 : 1.5 (this corresponds to m o l a r ratios o f 0 . 1 5 : 1, 0.11 : 1, 0.08 : 1 a n d 0.05 : 1). T h e initiator was dissolved in the m o n o m e r , t h e P E a d d e d , a n d t h e solution o b t a i n e d was c h a r g e d into ampoules. I n o r d e r t o d e t e r m i n e t h e q u a n t i t y o f t h r e e - d i m e n s i o n a l c o p o l y m e r formed, t h e a m p o u l e s were h e a t e d a n d after a certain t i m e were r a p i d l y cooled a n d the c o n t e n t s e x t r a c t ed for 10 hr. The swollen c o p o l y m e r was dried i n vacuo ( ~ 5 m m Hg) a t 70°C t o c o n s t a n t weight.

"r, 3

8O

2 I c)

~0

I

0

100

I

I

200 300 ~'me , re~z7

I

1

4##

500

Fzo. 1. Concentration of the PE-MMA copolymer fraction insoluble in CHsC1, as a function of the duration of copolymerization. Ratio of P E : M M (by weight): 1--2 : 1; 2--1"5 : 1; 3--1 : 1; 4--1 : 1.5.

fO0 .x3 a2

,,-0/

80

2O I

0

100

200

I

300 Z-~me,rain

I

1

/-tOO

500

FIG. 2. Concentration of the PE-styrcne copolymer fraction insoluble in C,H6, as a

function of the duration of copolymerization. Ratio of PE : styrene (by weight): 1--2 : 1; 2--1.5 : 1; 3--1 • 1; 4--1 : 1.5.

M. F. S o ~ t o ~ and I. MA~OVIOHU

2340

The experimental data indicate (Figs. 1 and 2) t h a t t h e yield of three-dimensional copolymer With ~ rises with the duration of the reaction (practically reaching a m a x i m u m value in 3 hr) and falls with an increase in the ratio of the polyester PE: vinyl monomer. Clearly, with an increase in the number of allyl groups in the reaction mixture chain termination of the vinyl macroradicals takes place more frequently, and because of this macromolecules are formed with a smaller molecular weight and with less three-dimensional structure (and consequently greater solubility). I n the s t u d y of the copolymerization of P E with styrene it was found t h a t an insoluble copolymer begins to be formed after a certain time, the length of which is inversely proportional to the number of allyl groups in the reaction mass. I t is interesting t h a t the intersection of the curves presented in Fig. 2 thus takes place at practically a single point. Unfortunately the experimental data obtained did not make it possible for us to explain this fact.

80 I

~60

~6o

4O

2O 0

•

1oo

300

Fro. 3.

I

500

T,oc

0

I

lOO

300

I

500 T,°C

Fro. 4.

FIG. 3. Weight losses on heating: 1--PE; 2--PE--styrene copolymer; 3--PE-MMA copolymer. Copolymers obtained with a weight ratio of PE • vinyl monomer of 1 : 1. Fio. 4. Weight losses on heating. 1--PE; 2, 3--PE-MMA copolymers, obtained with weight ratios PE : MMA of 1.5 : 1 and 1 : 1.5 respectively; 4, 5--PE-styrene copolymers, obtained with weight ratios PE : styrene of 1.5 : 1 and 1 : 1.5 respectively.

The copolymers synthesized from P E with both MiYIA and styrene take the form of solid products with an amber colour, insoluble and infusible. T h e y become less brittle as the concentration of the vinyl component is increased. We had previously shown [1] t h a t the pure P E is ignited with difficulty and has the capacity of being immediately self-extinguishing. Since the copolymers obtained eontain less phosphorus t h a n P E (see Table), it is completely natural t h a t when t h e y are introduced into a flame t h e y are easily ignited, and t h a t

Graft copolymers of the polyester

2341

when the flame is removed t h e y extinguish themselves not immediately, but after a few seconds (pure P ~ M A and polystyrene continue to burn until completely carbonized).

CONCENTRATION

OF PHOSPHORUS

IN

PE

AND

IN

ITS

COPOLYMERS

WITH

MMA

AND

WITH

STYRENE

Polymer

PE PE ~-MMA

Weight ratio PE : monomer

Phosphorus concentration, %

2:1 1.5:1 1:1 1:1.5

9-02 5"16 4"27 2'82 2"33

Polymer

PE -~styrene

Weight ratio PE : monomer

Phosphorus concentration, %

2:1 1.5:1 1:1 1:1.5

6.02 4.82 3-89 3.32

I t is known t h a t m a n y polymers and copolymers containing phosphorus are distinguished from ordinary polymers by their better heat resistance. We therefore determined the weight losses on heating the synthesized P E and its copolymers with MM~ and with styrene. For this purpose, the specimens were tested on a recording balance (system " F . Paulik, I. Paulik, L. Erdei, 676") in an atmosphere of air in the temperature range 20-500°C, at a heating rate of 5°C/rain. On the basis of the experimental thermal gravimetrie curves, the weight losses of the polymers were calculated as a function of temperature. In Figs. 3 and 4 are shown the curves for the polyester P E and its copolymers with MM~ and with styrene, synthesized at weight ratios of polyester : vinyl monomer equal to 1.5 : 1, 1.1 : 1 and 1 : 1.5. The data obtained indicate t h a t P E begins to lose weight when heated above 250°C (only slight losses up to 300°C), whereas its copolymers with MMA and with styrene lose weight starting from 100°C. Further heating leads to an increase in the rate of degradation of the copolymers, especially in the range 250-425°C. As was to be expected, the weight losses fall with an increase in the concentration of phosphorus, and thus, over the given temperature range, the weight losses for copolymers with M ~ A are greater t h a n for copolymers with styrene. Above 425-450°C the rate of degradation of the specimens falls, and the weight losses for P E on heating to 500°C amount to 64.4%, and for its copolymers with styrene or with MMA (obtained, for example, with a ratio of P E : vinyl monomer of 1 : 1.5) the weight losses are 81.6 and 86.0% respectively. The copolymers synthesized are very promising for use as heat resistant coatings and as glassy plastics. Because of their insolubility and infusibility, their use for such purposes is possible only by depositing the liquid mixture of the

2342

M. F. SOROYJN and I. MA~OVICH~r

a p p r o p r i a t e P E a n d v i n y l m o n o m e r on to the surface (or b y drawing it into a glassy fibre) a n d b y carrying o u t t h e c o p o l y m e r i z a t i o n subsequently, as is widely p r a c t i s e d w i t h the so-called u n s a t u r a t e d p o l y e s t e r resins. CONCLUSIONS

(1) T h e process o f g r a f t c o p o l y m e r i z a t i o n of t h e p o l y e s t e r of t h e acid dichloride o f allylphosphinic acid a n d d i p h e n y l o l p r o p a n e (PE) with m e t h y l m e t h a c r y l a t e a n d s t y r e n e has been studied. (2) I t has been shown t h a t t h e yield o f three-dimensional copolymers is inversely p r o p o r t i o n a l t o the ratio P E : v i n y l m o n o m e r . (3) Copolymers o f P E w i t h m e t h y l m e t h a c r y l a t e a n d s t y r e n e t a k e the f o r m o f solid substances w i t h an a m b e r colour, insoluble a n d infusible, a n d serf-extinguishing. T h e i r h e a t resistance is increased as t h e c o n c e n t r a t i o n o f p h o s p h o r u s in t h e c o p o l y m e r is increased. Translated by G. F. MODLEN REFERENCES

1. M. F. SOROKIN and I. MANOVICHU, Vysokomol. soyed. 8: 444, 1966 (Translated in Polymer Science U.S.S.R. 8: 3, 486, 1966) 2. Ye. A. GEFTER and M. K. RUBTSOVA, Act. svid. 111889; Byull. izobret., No. 3, 100, 1958 3. I. K. RUBTSOVA, Ye. A. GEFTER, A. YULDASHEV and P. A. MOSB'KIN, ZhVKhO ira. D. I. Mendeleyeva 2: 229, 1961 4. I. K. RUBTSOVA, Ye. A. GEFTER, A. YULDASHEV and P. A. MOSHKIN, Plast. massy, No. 2, 22, 1961 5. Ye. A. GEFTER, I. K. RUBTSOVA and S. I. SHNER, Art. svid. 134872; Byull. izobret., No. 1, 45, 1961 6. I. K. RUBTSOVA, Ye. A. GEFTER, A. YULDASHEV and P. A. MOSHKIN, Plast. massy, No. 3, 13, 1961 7. Ye. A. GEFTER and I. K. RUBTSOVA, Art. svid. 132404; Byull. izobret., No. 19, 54, 1960 8. Ye. A. GEFTER and A. YULDASHEV, Plast. massy, No. 2, 49, 1962 9. V. V. KORSHAK, I. A. GRIBOVA, M. A. ANDREYEVA, M. I. KABACHNIK and T. Ya. MEDVED', Sb. Geterotsepnye vysokomolekulyarnye soyedineniya (Symposium: Heterochain High Molecular Weight Compounds.) p. 117, Izd. Nauka, 1964 10. R. C. LABILE, Chem. Rev. 58: 807, 1958