Durability of Macromolecular Materials - American Chemical Society

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Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 16, 2016 | http://pubs.acs.org Publication Date: April 2, 1979 | doi: 10.1021/bk-1979-0095.ch013

Polyphenylene Sulfide: Stability and Long-Term Behavior H. WAYNE HILL, JR. Phillips Petroleum Co., Bartlesville, OK 74004

Polyphenylene sulfide (PPS) is an engineering p l a s t i c prepared by the reaction o f p-dichlorobenzene and sodium sulfide i n a polar solvent. As produced in the polymerization reaction, it is a l i n e a r polymer o f modest molecular weight. However, heating this v i r g i n resin below its melting point o f 285°C i n air y i e l d s products o f substantially lower melt flow. The melt flow o f these cured resins may be controlled by the specific choice o f cure conditions. These cured polymers are much tougher than the v i r g i n resin and provide the basis f o r a family o f injection moldable engineering plastics that exhibit excellent affinity f o r pigments, glass fibers and mineral fillers. Polyphenylene s u l fide resins are characterized by a combination o f useful propert i e s including good thermal stability, excellent chemical r e s i s tance, good mechanical properties, non-burning and non-dripping flammability behavior, and resistance to a wide variety o f environmental conditions. Polyphenylene sulfide resins have been produced commercially since 1973 by Phillips Petroleum Company and are sold under the trademark Ryton®. 1

Injection Molding Characteristics This paper 1s concerned primarily with three basic grades o f polyphenylene sulfide: (1) 40% glass-filled polymer (Grade R-4), (2) a glass- and m i n e r a l - f i l l e d polymer (Grade R-8), and (3) a glass- and m i n e r a l - f i l l e d color compound family (Grade R-10). While optimum injection molding conditions may vary slightly with mold design, part dimensions and resin grade, i n general, a stock temperature of 315-330 C and a mold temperature o f 120-130 C is preferred. Differential thermal analysis o f u n f i l l e d PPS indicates a c r y s t a l l i n e melting point of 2 8 5 ° C , a glass transition temperature (Tg) o f 85 C, and a pre-melt c r y s t a l l i z a t i o n temperature o f about 130 C. Thermal history of a molded specimen determines the degree o f c r y s t a l l i n i t y o f the specimen and to some extent the mechanical O

o

o

O

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0-8412-0485-3/79/47-095-183$05.00/0 © 1979 American Chemical Society Eby; Durability of Macromolecular Materials ACS Symposium Series; American Chemical Society: Washington, DC, 1979.


184

DURABILITY OF MACROMOLECULAR MATERIALS

and thermal behavior o f the molded p a r t . When a p a r t 1s molded In a mold below the Tg value o f 85°C, f t i s s u b s t a n t i a l l y amorphous ( l e s s than 5% c r y s t a l l i n e ) . On the other hand, when the mold temperature employed Is about 130°C, a high c r y s t a l l i n i t y (ca. 60%) i s obtained.3 The amorphous p a r t can be caused to c r y s t a l l i z e by annealing i n an oven a t 200°C f o r about 30 minutes. In g e n e r a l , the optimum p r o p e r t i e s are r e a l i z e d when the c r y s t a l l i n i t y l e v e l i s high. Unless otherwise s t a t e d , p r o p e r t i e s quoted i n t h i s paper were measured on well c r y s t a l l i z e d samples. Mechanical

Behavior

The mechanical p r o p e r t i e s o f the three f i l l e d grades o f polyphenylene s u l f i d e are given i n Table I. The 40% g l a s s f i l l e d m a t e r i a l has the lowest d e n s i t y and the h i g h e s t values f o r t e n s i l e s t r e n g t h , f l e x u r a l s t r e n g t h , compressive s t r e n g t h , impact s t r e n g t h and hardness. The g l a s s - and m i n e r a l - f i l l e d composition o f f e r s a good balance o f p r o p e r t i e s a t a s u b s t a n t i a l c o s t s a v i n g s , and the g l a s s - and m i n e r a l - f i l l e d c o l o r compounds o f f e r competitive p r o p e r t i e s and a t t r a c t i v e c o l o r s a t an i n t e r mediate c o s t . TABLE I MECHANICAL PROPERTIES OF POLYPHENYLENE SULFIDE COMPOUNDS 40% Glass Filled D e n s i t y , g/cc 1.6 T e n s i l e s t r e n g t h , MPa 135 Elongation, % 1.3 F l e x u r a l modulus, MPa 11,700 F l e x u r a l s t r e n g t h , MPa 200 Compressive s t r e n g t h , MPa 145 Izod Impact s t r e n g t h , J/m Unnotched 430 Notched 75 Shore D hardness 92 Heat d e f l e c t i o n temp. (264 p s 1 ) , °C >260

Glass/Mineral Filled 1.8 92 0.7 13,100 141 110 117 27 88 >260

Glass/Mineral F i l l e d Color (Natural ) 1.97 69 0.5 12,400 121 114 91 37 90 >260

The r e t e n t i o n of p r o p e r t i e s of 40% g l a s s - f i l l e d PPS a t tempe r a t u r e s o f 93, 149 and 204°C as a per cent o f the room temperat u r e value are given i n F i g u r e I . In g e n e r a l , t h i s m a t e r i a l r e t a i n s about 80% o f the o r i g i n a l property values a t 93C, 60 per cent a t 1490C and 40 per cent a t 204°C. The f l e x u r a l f a t i g u e endurance l i m i t (ASTM D671) provides i n f o r m a t i o n on the a b i l i t y o f a m a t e r i a l to r e s i s t mechanical 4

Eby; Durability of Macromolecular Materials ACS Symposium Series; American Chemical Society: Washington, DC, 1979.


HILL

Polyphenylene

Sulfide

RETAINED

SHEAR COMPRESSIVE NOTCHED STRENGTH YIELD IMPACT STRENGTH INITIAL VALUE

200 MPa

13800 MPa

97 MPa

152 MPa

SHORE D HARDNESS

79 J m

FIGURE 1 E F F E C T O F T E M P E R A T U R E O N PROPERTIES OF G L A S S FILLED PPS

Figure 1.

Effect of temperature on properties of glass-filled PPS


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DURABILITY O F

MACROMOLECULAR

MATERIALS


d e t e r i o r a t i o n as a r e s u l t o f a r e l a t i v e l y l a r g e number o f c y c l e s of constant amplitude o f f o r c e . T h i s l i m i t i s r e p o r t e d as the s t r e s s l e v e l a t which no f a i l u r e s occur a t 107 c y c l e s . The values f o r 40% g l a s s - f i l l e d PPS and g l a s s / m i n e r a l f i l l e d PPS are 45 MPa and 21 MPa r e s p e c t i v e l y . The 40% g l a s s - f i l l e d compound behaves s i m i l a r l y t o o t h e r g l a s s - f i l l e d e n g i n e e r i n g p l a s t i c s i n this test. Thermal S t a b i l i t y Thermogravimetric a n a l y s i s o f u n f i l l e d PPS i n n i t r o g e n o r i n a i r i n d i c a t e s no a p p r e c i a b l e weight l o s s below about 500°C (Figure 2 ) . In t h i s a n a l y s i s , degradation i s e s s e n t i a l l y comp l e t e i n a i r a t 700°C, but i n an i n e r t atmosphere, approximately 40% o f the polymer weight remains a t 1,000°C. Thermogravimetric a n a l y s i s i s i n h e r e n t l y a s h o r t - t e r m , weight l o s s measurement and, as such, i s o n l y i n d i c a t i v e o f thermal s t a b i l i t y i n a p r a c t i c a l sense. Long term oven aging o f the 40% g l a s s - f i l l e d PPS i n a i r was done a t temperatures ranging from 204°C t o 246°C. F i g u r e 3 shows the r e t e n t i o n o f t e n s i l e s t r e n g t h (measured a t room temperature) f o r times up t o 9,500 hours (13 months). A f t e r an i n i t i a l decrease d u r i n g the f i r s t 4-5,000 hours, the t e n s i l e s t r e n g t h remains l a r g e l y unchanged d u r i n g the remainder o f the exposure p e r i o d . A t the upper exposure temperature o f 246°C, the i n i t i a l drop i n t e n s i l e s t r e n g t h i s slower than a t the lower exposure temperature. T h i s i s presumably due t o some c u r i n g o r c r o s s l i n k i n g o f the polymer a t t h i s temperature. A t the end o f the exposure p e r i o d a l l t h r e e samples e x h i b i t e d very s i m i l a r t e n s i l e strengths. Figure 4 shows s i m i l a r oven aging data on g l a s s - and m i n e r a l f i l l e d polyphenylene s u l f i d e a t temperatures o f 232C, 260°C and 274°C. Again d u r i n g the f i r s t 6-7,000 hours o f exposure, the samples exposed a t the h i g h e r temperatures r e t a i n higher t e n s i l e s t r e n g t h s . Again t h i s i s presumably due t o c r o s s l i n k i n g d u r i n g exposure. Underwriters L a b o r a t o r i e s has a u t h o r i z e d temperature i n d i c e s of 170OC f o r the 40% g l a s s - f i l l e d PPS and 200°C f o r the g l a s s and m i n e r a l - f i l l e d r e s i n . The g l a s s - and m i n e r a l - f i l l e d c o l o r compounds have a p r o v i s i o n a l UL Temperature Index o f 200OC. When polyphenylene s u l f i d e i s heated i n a i r a t approximately 815°C, the major components o f thermal degradation a r e : hydrogen, methane, carbon monoxide, carbon d i o x i d e and carbonyl s u l f i d e . In a d d i t i o n , minor amounts o f s u l f u r d i o x i d e and ethane o r ethylene are a l s o formed. The creep behavior o f 40% g l a s s - f i l l e d polyphenylene s u l f i d e 1s summarized In F i g u r e 5 which p l o t s creep modulus a g a i n s t time f o r t h r e e sets o f experimental c o n d i t i o n s : 23°C/5,000 p s i , 66OC/5,000 p s i , and 121°C/5,000 p s i . T a b l e II compares the per cent l o s s i n apparent creep modulus a t 1,000 hours and a t 10,000 1


13.

HILL

Polyphenylene Sulfide


\V NITROGEN ATMOSPHERE

-

WEIGHT LOSS, %

— \ \

I

100 0

I

I

IL-

1

1

AIR ATMOSPHERE "

V-

1

I

100 200 300 400 500 600 700 800 900 1000 TEMPERATURE, °C

FIGURE 2 POLYPHENYLENE SULFIDE - THERMOGRAVIMETRIC ANALYSIS Figure 2. Polyphenylene sulfide-thermogravimetric analysis (DuPont 950 TGA instrument; heating rate, 15°C/min; atmosphere purge, 40 cc/min)

Figure 3.

Oven aging of 40% ghss-filled PPS in air



^274 C e

-


— 2 6 0 ° C

TENSILE STRENGTH, MPa

4 0

——

-

232«C

-

3 0

1 i I I 1 1 1 1 1 1000 2000 3000 4000 5000 6000 7000 8000 9000

EXPOSURE TIME IN HOURS Figure 4.

Oven aging of glass- and mineral-filled PPS in air

10* 66°C; APPLIED STRESS, 5000 PSI CREEP MODULUS, PSI 10

-

23°C; APPLIED STRESS, 5000 PSI

-

121°C; APPLIED STRESS, 5000 PSI 5

10"

1

I 10°

I ,„ ί 10 10 TIME, HRS 1

2

1

10

3

10

4

FIGURE 5 CREEP (APPARENT) MODULUS OF 40% GLASS FILLER PPS Figure 5.

Creep (apparent) modulus of 40% glass-filled PPS


13.

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Polyphenylene

189

Sulfide

hours f o r eatch o f these c o n d i t i o n s ustng the s p p s r e n t creep modulus a t one hour as a b a s i s . These data i n d i c a t e good creep resistance f o r a thermoplastic material with a glass transition o f 85°C f o r the base polymer. TABLE I I Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 16, 2016 | http://pubs.acs.org Publication Date: April 2, 1979 | doi: 10.1021/bk-1979-0095.ch013

LOSS IN APPARENT CREEP MODULUS FOR 40% GLASS FILLED PPS Test Condition Temp., QÇ S t r e s s , p s T 23 66 121

5,000 5,000 5,000

Loss i n Apparent Creep Modulus, % 1,000 Hours' 10,000 Hours 7.8 20.7 22.6

a

8.9 24.7 29.8

a - P e r c e n t l o s s between one hour and I n d i c a t e d time. S i m i l a r l y , F i g u r e 6 summarizes t h e creep b e h a v i o r o f g l a s s and m i n e r a l - f i l l e d polyphenylene s u l f i d e under t h r e e s e t s o f c o n d i t i o n s : 24°C/5,000 p s i f l e x u r a l l o a d , 66°C/5,000 p s i , and 121°C/3,000 p s i . T a b l e I I I compares t h e p e r c e n t l o s s i n apparent creep modulus a t 1,000 hours and a t 10,000 hours f o r each o f these c o n d i t i o n s using t h e apparent creep modulus a t one hour as a b a s i s . These data i n d i c a t e t h a t t h e creep r e s i s t a n c e o f t h e g l a s s - and m i n e r a l - f i l l e d polymer i s s i m i l a r t o t h a t o f t h e 40% glass-filled resin. TABLE I I I LOSS IN APPARENT CREEP MODULUS FOR GLASS- AND MINERAL-FILLED PPS Test Conditions Temp., °C S t r e s s , p s i 24 66 121

5,000 5,000 3,000

Loss i n Apparent Creep Modulus, % 1,000 Hours 10,000 Hours 8.2 20.0 16.0

a

11.6 25.6 21.4

a - P e r c e n t l o s s between one hour and i n d i c a t e d time. E l e c t r i c a l Behavior The e l e c t r i c a l p r o p e r t i e s o f t h e three polyphenylene s u l f i d e compounds a r e given i n T a b l e IV. The 40% g l a s s - f i l l e d PPS i s t h e best i n s u l a t o r as i n d i c a t e d by t h e d i e l e c t r i c c o n s t a n t o f 3.8. The two compounds which c o n t a i n g l a s s - and m i n e r a l - f i l l e r s p r o v i d e the b e s t a r c r e s i s t a n c e and t r a c k i n g Index. A l l t h r e e m a t e r i a l s p r o v i d e a good balance o f e l e c t r i c a l p r o p e r t i e s .


! CREEP MODULUS, PSI

• =

1 11

I 24°C; APPLIED STRESS, 5000 PS

I

I

1

I

66 C; APPLIEI>STRESS, 5000 PSI e

I

121 C :; APPLIED STRESS, 5 000 PSI = e

llll 1 1 1 1



10"

1

10°

10 10 TIME, HRS. FIGURE 6 1

2

10

3

CREEP (APPARENT) MODULUS OF GLASS AND MINERAL FILLED PPS Figure 6.

Creep (apparent) modulus of glass- and mineral-filled PPS


10

4

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Polyphenylene

191

Sulfide

TABLE IV ELECTRICAL PROPERTIES OF POLYPHENYLENE SULFIDE COMPOUNDS


Glass and Glass and 40% Glass MineralMineral-filled Filled Filled Color (Black)

Property Dielectric strength, 1 kHz, volts/mil 350 Dielectric constant, 1 MHz 3.8 Dissipation factor, 1 MHz 0.0013 Volume resistivity, 2 min. Ohm-cm 4.5x1016 Arc resistance, sec. 35 Comparative tracking index, volts 180

340 4.6 0.016 2.0x1015 200

324 5.1 0.019 1.3x1015 200

235

235

T a b l e V i n d i c a t e s t h e good r e t e n t i o n o f e l e c t r i c a l propert i e s e x h i b i t e d by t h e 40% g l a s s - f i l l e d PPS a t temperatures up t o 147°C. In a d d i t i o n , exposure o f t e s t specimens t o 50 p e r cent r e l a t i v e humidity f o r 5 days d i d not cause any a p p r e c i a b l e change i n e i t h e r d i e l e c t r i c constant o r d i s s i p a t i o n f a c t o r . Thus, environmental f a c t o r s do not have much e f f e c t upon the e l e c t r i c a l behavior o f polyphenylene s u l f i d e r e s i n s . TABLE V ELECTRICAL PROPERTIES OF 40% GLASS-FILLED PPS AT ELEVATED TEMPERATURES' Property D i e l e c t r i c Constant 1 0 Hertz 1 0 Hertz 3

6

Dissipation Factor 103 Hertz 106 Hertz

Temperature 27C lOQQÇ 3.9 3.8 0.0010 0.0013

3.9 3.8 0.0016 0.0015

147°C 4.0 3.9 0.0065 0.0051

Flammability Behavior Polyphenylene s u l f i d e w i l l not burn when t e s t e d by any o f t h e common standard t e s t s used f o r p l a s t i c s , such as ASTM D635 and UL-94. However, when exposed i n a f i r e , i t w i l l continue t o burn u n t i l t h e e x t e r n a l l y a p p l i e d flame i s removed. I t burns w i t h a yellow-orange flame, producing gray smoke w i t h t r a c e s o f b l a c k . I t does not d r i p and the char i s b l a c k and g l o s s y . The UL i g n i t i o n temperature o f t h e 40% g l a s s - f i l l e d r e s i n i s 540°C.


192


Table VI summarizes the f l a m m a b i l i t y behavior o f the three f i l l e d PPS r e s i n s by a v a r i e t y o f f l a m m a b i l i t y t e s t s . TABLE VI


FLAMMABILITY OF FILLED PPS RESINS

Flammability T e s t

40% G l a s s Filled PPS

G l a s s and MineralF i l l e d PPS

G l a s s and MineralF i l l e d Colored

ASTM D635 Oxygen index UL-94

Non-burning 46.5 V-0

Non-burning 53 V-0

Non-burning 50 V-0

The smoke d e n s i t y t e s t developed by the National Bureau o f Standards employs a completely c l o s e d c a b i n e t , measuring 3 f e e t wide, 3 f e e t high and 2 f e e t deep, i n which a specimen 3 inches square i s supported i n a frame such t h a t a s u r f a c e area 2-9/16 inches souare i s exposed to heat under e i t h e r f l a m i n g o r nonf l a m i n g (smoldering) c o n d i t i o n s . The heat source i s a c i r c u l a r f o i l radiometer adjusted to g i v e a heat f l u x o f 2.5 watts per square centimeter a t the specimen s u r f a c e . The photometer path f o r measuring l i g h t a b s o r p t i o n i s v e r t i c a l , t o minimize measurement d i f f e r e n c e s due to smoke s t r a t i f i c a t i o n which c o u l d occur with a h o r i z o n t a l photometer path a t a f i x e d h e i g h t , and the f u l l 3-foot height o f the chamber i s used t o provide an o v e r a l l average f o r the e n t i r e chamber. Smoke measurements are expressed i n terms o f s p e c i f i c o p t i c a l d e n s i t y , which represents the o p t i c a l d e n s i t y measured over u n i t path length w i t h i n a chamber o f u n i t volume produced from a specimen o f u n i t s u r f a c e a r e a ; s i n c e t h i s value i s d i m e n s i o n l e s s , i t provides the advantage o f p r e s e n t i n g smoke d e n s i t y independent o f chamber volume, specimen s i z e or photometer path l e n g t h , provided a c o n s i s t e n t dimensional system i s used. The time t o reach a c r i t i c a l smoke d e n s i t y , a l s o c a l l e d the o b s c u r a t i o n time, i s a measure o f the time a v a i l a b l e before a t y p i c a l occupant i n a t y p i c a l room would f i n d h i s v i s i o n obscured by smoke s u f f i c i e n t l y to hinder escape. The value o f s p e c i f i c o p t i c a l d e n s i t y d e s c r i b i n g t h i s c r i t i c a l l e v e l i s 16, based on 16 per cent l i g h t transmittance under c e r t a i n s p e c i f i c c o n d i t i o n s o f room dimensions. R e s u l t s o f smoke d e n s i t y measurements on 40% g l a s s - f i l l e d polyphenylene s u l f i d e are given i n Table V I I . These data i n d i cate t h a t PPS burns with the generation o f a r e l a t i v e l y small q u a n t i t y o f smoke.


13.

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Sulfide

193

TABLE VII Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 16, 2016 | http://pubs.acs.org Publication Date: April 2, 1979 | doi: 10.1021/bk-1979-0095.ch013

SMOKE DENSITY OF RYTON PPS Max. Value o f S p e c i f i c Obscuration Time, O p t i c a l Density minutes Smoldering Flaming Smoldering Flaming

Ryton

40% G l a s s - f i l l e d PPS 232 125 m i l s t h i c k 25 171 23 60 m i l s t h i c k 75 393 Red oak (25 m i l s t h i c k ) a a - Included f o r comparison purposes.

15.5 15.5 4.1

3.2 2.7 8.0

Chemical R e s i s t a n c e 5

Previous s t u d i e s comparing PPS t o o t h e r e n g i n e e r i n g thermop l a s t i c s e s t a b l i s h e d the r e l a t i v e s h o r t term (24-hour) chemical r e s i s t a n c e o f PPS moldings t o a wide v a r i e t y o f chemical e n v i r o n ments a t 93°C. A p o r t i o n o f these r e s u l t s a r e given i n Table VIII. More r e c e n t examinations have lengthened exposure time a t t h i s temperature t o 12 months f o r the 40% g l a s s - f i l l e d p o l y phenylene s u l f i d e (Table I X ) . Even under these severe c o n d i t i o n s under which most t h e r m o p l a s t i c r e s i n s would f a i l c a t a s t r o p h i c a l l y , the general chemical r e s i s t a n c e o f g l a s s - f i l l e d PPS was again manifested. R e s i s t a n c e t o phosphoric a c i d , water, a l c o h o l s , d i b u t y l e t h e r , butylamine, g a s o l i n e , c r e s y l d l p h e n y l phosphate, N-methyl p y r r o l i d o n e , and a i r was p a r t i c u l a r l y f a v o r a b l e . S l i g h t t o moderate a t t a c k was noted by s u l f u r i c a c i d , sodium hydroxide, sodium h y p o c h l o r i t e , methyl e t h y l ketone, c h l o r o f o r m , e t h y l a c e t a t e , dîoxane, a n i l i n e , t o l u e n e , b e n z o n t t r t l e , phenol and benzaldehyde. Severe a t t a c k r e s u l t e d upon exposure t o concent r a t e d h y d r o c h l o r i c a c i d , 10% n i t r i c a c i d , carbon t e t r a c h l o r i d e and nitrobenzene. T h i s chemical r e s i s t a n c e suggests t h e use o f PPS moldings i n many a p p l i c a t i o n s where harsh, c o r r o s i v e o r d i f f i c u l t t o handle chemical environments a r e encountered.



194

TABLE VIII Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 16, 2016 | http://pubs.acs.org Publication Date: April 2, 1979 | doi: 10.1021/bk-1979-0095.ch013

CHEMICAL RESISTANCE 93°C/24 hr

Chemical 37% 10% 30% 85%

HC1 HNO3 H2SO4 H3PO4

30% NaOH 28% H2O

NH4OH

FeCl 3 NaOCl Br? Butyl alcohol Phenol Butylamine Aniline 2-Butanone Benzaldehyde Chlorobenzene Chloroform Ethyl acetate Butyl phthalate p-Dioxane Butyl ether Gasoline Diesel fuel Toluene Benzonltrile Nitrobenzene

Per cent t e n s i l e r e t a i n e d Nylon Polycar Polysul- Modified ΡΡ0 6-6 bonate fone 0 0 0 0

89 85 66 13 44 8 87 0

90 85 87 98 73 57 89 90 96 100

80 87 76 88 100

0 100 100 100

7 0 100 100 100

48 94 0 0 0 0 0 0 0 0

46 0

61 99 100 0 0 0

100 100 100 100 100 100 100 100 100

92 100 0 0 0 0 0 0 0 0

63 0 100 100 100 0 0 0

100 100 100 100 100 100 100 100 100

87 84 0 0 0 0 0 0 0 0

19 0 0 0

PPS 100

96 100 100 100 100 100 100

84 64 100 100

50 96 100

84 100

87 100 100

88

36

100 100 100

0 0 0

100 100


98

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TABLE IX


LONG TERM CHEMICAL RESISTANCE OF 40% GLASS-FILLED PPS (Exposure Temperature, 93°C) 3

Chemical 37% 10% 30% 85%

HC1 HN0 H2SO4 H3PO4 3

30% NaOH Water Clorox n-Butyl alcohol Cyclohexanol Butylamine Methyl ethyl ketone Carbon tetrachloride Chloroform Ethyl acetate Butyl ether p_-D1oxane Gasoline Aniline Toluene BenzonitHle Nitrobenzene Phenol Benzaldehyde Cresyl diphenyl phosphate N-Methy1pyrroltdone A1r

Per cent Retention of Tensile strength after 24 Hr. 3 Mo. 6 Mo. 71 91 94 100 100

99 94 100 100

96 100 100

81 100 100

99 100 100 100 100 100 100

97 100 100

—

34 b 89 99 89 99 77 92 91 46 100

48 77 88 89 96 99 86 70 79 63 92 47 100

92 96

12

22

— 34 41 44 49 54 69 69 58 57 24 41 46 68 69 71 60 55 29 53 59 27 83 84 71

a - Compared t o unannealed, unexposed t e n s i l e bars, b - Specimens d i s i n t e g r a t e d .


Mo. 29 b 61 89 63 65 61 80 86 85 61 25 43 58 79 59 80 42 41 39 31 63 42 95 80 72

DURABILITY O F

196

MACROMOLECULAR

MATERIALS

A d d i t i o n a l Environmental R e s i s t a n c e Behavior The e f f e c t s o f neutron and gamma r a d i a t i o n on the mechanical behavior o f 40% g l a s s - f i l l e d polyphenylene s u l f i d e are summarized i n Table X. These data i n d i c a t e t h a t t h i s r e s i n i s q u i t e s t a b l e to environments i n v o l v i n g r a d i a t i o n . Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 16, 2016 | http://pubs.acs.org Publication Date: April 2, 1979 | doi: 10.1021/bk-1979-0095.ch013

TABLE X EFFECT OF RADIATION ON PHYSICAL PROPERTIES OF 40% GLASS-FILLED PPS Conditions Temperature Radiation Intensity Used p a r t i c l e detectors R a d i a t i o n dose 0 A. Gamma 5 χ 108 rad 1 χ 1 0 rad 5 χ 109 rad B. Neutron 5 χ 108 rad 1 χ 109 rad 9

In Reactor Core 350C

Mainly neutrons 108 rad C a l o r i m e t e r and activation detectors

In Water Pool 30C Mainly gamma 107 rad I o n i z a t i o n chamber

Modulus F l e x u r a l s t r e n g t h , MPa o f E l a s t i c i t y , MPa 198 13,091 205 208 196

12,470 12,670 12,540

200 199

13,160 12,950

The 40% g l a s s - f i l l e d PPS was aged i n an A t l a s Weather-Ometer f o r 10,000 hours. Changes i n t e n s i l e s t r e n g t h and e l o n g a t i o n were measured a t s p e c i f i c time i n t e r v a l s . T e s t s were performed on a c o n t r o l r e s i n with no UV i n h i b i t o r , one with 1% T i n u v i n 327 and one w i t h 1% UV 531. The r e s u l t s a r e shown i n Table XI. These data i n d i c a t e moderate s t a b i l i t y t o u l t r a v i o l e t r a d i a t i o n without s t a b i l i z e r s and improved s t a b i l i t y with s t a b i l i z e r s .


13.

197


HILL

TABLE XI


EFFECT OF WEATHER-OMETER EXPOSURE ON TENSILE PROPERTIES OF 40% GLASS-FILLED PPS

Hours Exposed

Resin + 1% Resin + 1% Resin Control T1nuv1n 327 UV 531 Tensile, Elong. Tensile, Elong. Tensile, Elong. MPa % MPa % MPa %_

0 115 1.10 2,000 105 1.20 6,000 106 1.38 8,000 98.9 1.23 10,000 72.7 0.60 % Tensile reduct1on37 45 Erosion, mils 13

113 1.20 109 1.30 104 1.23 97.8 1.15 103 0.95 9 21 11

115 1.35 103 1.15 100 1.15 93.7 1.05 88.5 1.00 23 26 11

Conclusions Three f i l l e d injection molding grades o f polyphenylene s u l fide were described: (1) 40% g l a s s - f i l l e d polymer, (2) a glassand m i n e r a l - f i l l e d polymer and (3) a glass- and m i n e r a l - f i l l e d color compound family. Polyphenylene sulfide i s a crystal!Izable polymer and optimum behavior i s realized i n well c r y s t a l l i z e d parts. These may be obtained by molding into a hot ( 1 2 0 - 1 3 0 ° C ) mold o r by annealing ( 2 0 0 ° C / 3 0 minutes) the molded part. The f i l l e d resin compositions are strong, s t i f f and hard, and mechani c a l properties are retained well a t temperatures up to about 200°C. Oven aging f o r 10,000 hours a t temperatures from 204OC t o 2720C indicate excellent retention o f t e n s i l e strength. The f i l l e d polymers are also resistant to creep. A variety o f elect r i c a l properties are available by appropriate choice o f r e s i n / f i l l e r composition and properties are retained a t temperatures up to about 150°C. The various f i l l e d resins do not burn when tested by commonly used t e s t s , but w i l l burn as long as an externally applied flame i s maintained. Smoke generation i s low. Chemical resistance o f the 40% g l a s s - f i l l e d PPS i s excellent i n tests a t 93°C f o r 1 year's exposure. References Phillips

1.

2. 3. 4. 5.

Edmonds, J. T., Jr. and Hill, H. W., Jr., U.S. 3, 354, 129 to Petroleum Company (November 21, 1967). Short, J. N. and Hill, H. Wayne, Jr., Chemtech 2 , 481 (1972). Brady, D. G., J. Appl. Poly. Sci. 20, 2541 (1976). Hill, H. Wayne, Jr. and Brady, D. G., Poly. Eng. andSci.16, 831 (1976). Brady, D. G . and Hill, H. W., Jr., Mod. Plast., 51, No. 5 , 60 (1974).

RECEIVED

December 8, 1978.


Durability of Macromolecular Materials - American Chemical Society

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