Document wDnbn4jRb0ayKOjO4OvQqekOo

FILLED POLYPROPYLENE. I DEVELOPMENT OF TALC-FILLED GRADES by N. E. Frailey Technical Progress Report WPR 8-66 Uniform Research Project Code No. 66229 This report is based on work from October 1965 to March 1966. Written and Reviewed: Approved: Participant: Reference: N. E. Frailey and D. K. Peterson M. E. Doyle G. W. Powers Laboratory Record Book No. CWLR 127 PLASTICS TECHNICAL CENTER WOODBURY, NEW JERSEY PRIVATE AND CONFIDENTIAL TECHNICAL PROGRESS REPORT DISTRIBUTION Head Office Tecnnical Information Services (19) Manager, Union Laboratories Industrial Chemicals Division Director, Houston Research & Development Laboratory Plastics and Resins Division Manager, Woodbury Plant Manager, Polystyrene Operations, Wallingford Synthetic Rubber Technical Center Manager, Research and Development Research Director, Torrance Research Laboratory Shell Oil Company ' Manager, Manufacturing Research Dept, New York Research Director, Houston Research Director, Wood River Shell Development Company President, New York (2) Emeryville Research Center (l4) Director, Modesto Shell Pipe Line Corporation Manager, Technical Development Laboratory, Houston For Information: Shell Canada, Limited Manufacturing Department, Toronto, Ontario Export of this document is subject to license under the Export Control Act of 1949. SCC-4 ABS-q 43934 TABLE OF CONTENTS ABSTRACT INTRODUCTION EXPERIMENTAL RESULTS AND DISCUSSION CONCLUSIONS APPENDIX Page 1 2 3 k 6 T ABS-0439351 ABSTRACT Experimental filled polypropylene grades with properties to satisfy a range of requirements have been developed. These are based on kof, Mistron Vapor talc in propylene homopolymer and copolymer. Talc particle size has more effect on the physical properties of filled polypropylene than does particle shape. ABS-043936 INTRODUCTION 2 A filler is added to a polymer to improve certain mechan ical properties for a specific end-use. Generally, these properties are flexural modulus, heat distortion temperature, and creep resistance. Most fillers are capable of significantly improving these properties; in almost every case, however, there is a con current sacrifice in impact strength, end-use oxidative stability, water absorption, and color in the blend. Perhaps of equal importance, incorporation of the filler into the polymer must be readily accomplished (preferably in conventional equipment) for a filled grade to be economically attractive. Thus, the ideal filler must impart an unusual balance of properties to the filled system. At the present time, the market for filled polypropylene is growing rapidly, and is expected to increase from approximately 7 MM lb in 1965 to an estimated 15-20 MM lb per year by 1967. Automobile manufacturers are employing filled polypropylene for air ducts, fan and radiator shrouds, and electrical components; while the appliance industry is'using it for various washing machine, dishwasher, and garbage disposal parts. At present Shell Polypropylene WM-650, which contains 32.1$ asbestos, 6.4$ zinc oxide, and 3-6$ carbon black in propylene homopolymer, is our only semi-commercial grade of filled polypropylene.^ This material has been sampled to the automotive industry for use in the applications mentioned above; however, approval has been limited by three major deficiencies impact strength, oxidative stability, and weld strength. Studies have, therefore, been conducted to overcome these deficiencies by making various modifications to the standard WM-65O formulation; the results are included in the present report. ABS-0439371 EXPERIMENTAL 3 Initially in our study, several formulations, described in Table 1, were prepared by the outside compounder-'-' whom the plant presently employs for WM-650 production. Based on these results, four grades of talc of varying particle size and shape (described in Table 2) were evaluated in propylene homopolymer and copolymer. The formulations, shown in Table 3> were prepared via extrusion compounding using a twin-screw Welding Engineers Incorporated (WEI) extruder. The polypropylene powder and fillers were blended in a Henschel mixer for two minutes prior to crammer feeding and extruding. These experimental samples and two com petitive grades of talc-filled polypropylene were injection molded into ASTM specimens and tested for selected physical properties. Double-gated tensile bars were also prepared from various samples and tested for tensile strength in the weld line area. The oven life of 110-mil plaques was measured at 150C on selected samples. lj The equipment train used by the compounder consists of a batch intensive mixer (Banbury-type) and a pelletizing extruder. ABS-04393^ h RESULTS AND DISCUSSION Substituting talc for asbestos in the WM-650 formulation results in an improved product (10A18), as shown in Table 1. The impact strength and oven stability of the talc-filled material are superior to that of WM-650, while the other physical properties are comparable. A comparison between the physical properties of this same experimental formulation prepared by the outside compounder and prepared by extrusion compounding further indicates that a talcfilled system can be prepared via extrusion compounding. The formulations discussed above contain carbon black and zinc oxide; both are expensive fillers compared to talc or asbestos. Therefore, samples with asbestos or talc substituted for zinc oxide and/or carbon black were evaluated. As shown by the data in Table 1, the non-black asbestos formulation has properties fully equivalent to the standard WM-650. Moreover, talc can be sub stituted for both the zinc oxide and carbon black (compare samples 3B32 and.3B33)>. Compared to WM-650, the homppolymer sample con taining talc has superior impact strength and oven stability without significant sacrifices in flexural modulus or heat distortion temperature. The weld strength is also marginally better than that of WM-650. Two experimental samples based upon the standard WM-650 formulation but with a copolymer substrate were also evaluated. The addition of either talc or asbestos to Shell Polypropylene V-526 (high impact tailblock copolymer) results in significant increases in flexural modulus and heat distortion temperature. However, the talc-filled system has significantly better oven stability. Based upon these results, four grades of talc of varying particle size and shape were evaluated in propylene homopolymer and copolymer to select the best grade of talc to be incorporated in these systems. As shown in Figures 1, 2, and 3> the talc particle size has more effect on the flexural modulus, impact strength, and yield elongation of the filled copolymer (V-526) than does the particle shape. The significant increase in notched Izod impact strength and the comparatively small reduction in yield elongation, illustrated, in Figures 2 and 3> obtained with the addition of Desertalc 57 is a result of orientation of the large particles in the ASTM test specimens. The impact strength of 60-mil compression-molded plaques prepared from the Desertalc 57 filled systems was comparable to those of the other talc-filled systems, as shown in Table 3- No significant relationship was observed between talc particle size and the other measured physical properties. ABS--04 B939 5 The results of this study agree remarkably well with results reported in the literature by H. Alter. ^-) In his study, it was shown that-the mechanical properties of filled poly ethylene are linear functions of the reciprocal of the filler particle diameter (d) and are independent of the chemical compo sition of the filler. The explanation given is that the l/d function is an expression of the dependence on the surface-tovolume ratio of the filler. The filler is a diluent in polymer; so the modulus is inversely proportional to the filler volume. However, the polymer also adheres to the filler surface, forming s network and increasing the modulus in proportion to the number of attachments or to the filler surface area. The net result is the dependence on the diameter of the filler. The significant inde pendence of the nature of the filler suggests that the polymerfiller adhesion, per unit available, is the same for all of the fillers. This seems reasonable if the non-polar polymers wet the higher surface energy fillers. Figures k through 7 show the effect of talc (Mistron Vapor) addition on the flexural modulus, impact strength, and heat distortion temperature at 26k psi for Shell Polypropylene 55XX and V-526. In addition, an estimate of the effect' of talc content on each property of talc-filled Shell Polypropylene V-521 (mediumimpact tailblock copolymer) is also shown in these figures. Based upon economic considerations and improvements in physical properties, a loading of 4o$ Mistron Vapor talc appears to be optimum in filled homopolymer and copolymer for use in present applications. Moreover, these relationships will permit us to alter the balance of properties for future specific end-uses. Compared to the competitive grades of talc-filled polypro pylene, our experimental talc-filled systems have a superior balance of impact strength and flexural modulus. The other physical properties are comparable. This is shown in Table 4, which also shows an average of some of the physical property specifications employed by the various automobile manufacturers for such applications as fan shrouds. As shown by the data, kQff, talc in polypropylene meets all of the automotive specifications, while WM-650, our asbestos-filled system, fails to meet the impact specification. 1) "Filler Particle Size and Mechanical Properties of Polymers", H. Alter, Journal of Applied Polymer Science, Vol 9> PP 1525 1531 (1965). tf ABS- 043940 6 CONCLUSIONS Substituting talc for asbestos in Shell Polypropylene WM-650 results in improved impact strength and oxidative stability without significant sacrifices in other physical properties. Talc particle size has a more significant effect on the flexural modulus, impact strength, and heat distortion temperature of filled polypropylene, than does the particle shape. From the study, three experimental talc-filled systems (40$ talc in Shell Polypropylene 55XX, V-521, and V-526) have been developed. Samples of the lOjfc talc in homopolymer, designated TC8-1, have been submitted to the automotive industry for their evaluation. Initial results are favorable. Further studies are planned with different types of mineral fillers of varying particle size and with various surface active agents. ABS-04 3941 7 APPENDIX Page Table 1. SELECTED PROPERTIES OF FILLED POLYPROPYLENES 8 Table 2. DESCRIPTION OF TALCS 9 Table 3- PROPERTIES OF EXPERIMENTAL TALC-FILLED POLYPROPYLENE 10 Figure 1. INFLUENCE OF TALC CONTENT, SHAPE, AND PARTICLE SIZE ON FLEXURAL MODULUS OF FILLED SHELL POLYPROPYLENE V-526 11 Figure 2. INFLUENCE OF TALC CONTENT, SHAPE, AND PARTICLE SIZE ON NOTCHED IZOD IMPACT STRENGTH AT T3F OF FILLED SHELL POLYPROPYLENE V-526 12 Figure 3. INFLUENCE OF TALC CONTENT, SHAPE, AND PARTICLE SIZE ON YIELD ELONGATION AT 0.2 IN,/MIN OF FILLED SHELL POLYPROPYLENE V-526 13 Figure 4. INFLUENCE OF TALC CONTENT ON FLEXURAL MODULUS OF FILLED PROPYLENE POLYMERS 14 Figure 5. INFLUENCE OF TALC CONTENT ON NOTCHED IZOD IMPACT STRENGTH AT 73F OF FILLED PROPYLENE POLYMERS 15 Figure 6. INFLUENCE OF TALC CONTENT ON IMPACT STRENGTH OF FILLED SHELL POLYPROPYLENE 55XX 16 Figure J. INFLUENCE OF TALC CONTENT ON HEAT DISTORTION 17 TEMPERATURE AT 264 PSI OF FILLED PROPYLENE POLYMERS Table 4. SELECTED PROPERTIES OF FILLED POLYPROPYLENES 18 I ABS- 043942 T a b le 1 . SELECTED PROPERTIES OF FILLED POLYPROPYLENES I S ta b ility a t 150C 29 110 m il plaques, days O In NO P<CM O > CJ PL, OJ rHH 0C) 4) C CO P>>L U 4> rOH UN &! J' 8' as i H H ON Pt 41 CO -P Sj o Ac o c X 4J rH qj WE Hw4XP)Hi -CC4aPND) OHOH<5 ,Pdc0i <3 Pi 0) 43l -d g UPfti +c) OMJ w-Xp KUrt "a u ! Ii -paj C ccoo. pq ,, w,, <au ro h O 8 OJ O UN CO OJ co rH OJ o o un OJ -4 oo 8c ^4 -4 rH OJ o rH O O UN 1 -4 VO ON rH rH CM 1 in CM............................. mvo on o O O O o 8 on CO ON -d- H in i \o * rH 1 o it--n rH a -4 no On oH orH iCnO iHn VO on O O o O O -OOm4 1 NO 1 -d* l 0irHn0 l OJ OJ cm U 8o IO -4 O O IAIA OVHHCOH o6ood o o no UN UN OJ UN -4. co UN c-- UN CO ON H o IA rH -4 NO O ON h O h ionn rmH l CM....................... CONO CO O O O o o Q <*) 00 -d* OJ CO ON 00 in CO in t-- ON rH o i I UN l Io CO D0 H UN <M NO >> H r| CO P 43 H 3 4J -P wfXtpaUHo s a u> Pi 43 43 -P Pi C H <5 O r3Qc wX 4a) H a rH UoN oCO P>i no *2 d Ho in 1 I CmVJ v-4o NmO ON oH oo orH o iCnVJ o 1 o CinO i -iodnn. i VvOo i ON oH o iCnO irnH ooooo o C-- in !1 rH -4 NO o ON rH o H in in CO rH & iO roo O o o o ooC- 1 NoOnN^Or ^1 rH -oOCd-- 1 UN. O NO -4 1 CHCMM 1 O a CO -4 CO NO -4 O CVJ UN ON CO On rH OJ CO O 4* CD 8 CM Oin CO ;o to CQ 1 <c 1 oon a o ON OJ ** T0d) Jh sj 0) 0) 4) I oCJ-Ol <3 4) ca JP3i Pi V 4J >P-1 U rH P0UL r-i' P. op, 43-Eq-ji P -eP- J3 0) > PL JPei H4U-3> O 4) Pi (0 ft-* 01 --- ProHH X*. - NO H CM Pi 1 O -P 0) MM>43 <40) 43 H o' to CO S3 CO S co hXh Pi Pi XC4O>! UUNN r4H) UIN e> >> O a oPai -dP go H43 y C 1 c rH OJ ,OJ o 3|o -p O & p 43 73 0 >d rH >L 43 a60 _ _ o>p. S xi HO W - -P H 1 a H C fPfli dh ha X h O 2S eh >h - -- 9 Table 2. DESCRIPTION OF TALCS Description Chemical Composition^ SiOp, % MgO, $ CaO, # Fe203> % H20+ (Chem combined), $ Na20, $ co2, $ Particle Size, n Maximum Average Particle Shaped) Surface Area,3) in.12/3g Mistron Vapor Mistron Super Frost 62.51 59-15 30.59 27.96 0.22 5.17 0.99 4.73 0.26 3.83 ' 0.09 1.6l 0.44 . 2.29 6.0 1.0 p 19-5 6.0 0.8 AP 25.5 Mistron Frost 59-15 27.96 5-17 0.26 3.83 1.61 2.29 10.0 3-0 AP 16 1) Major components only. 2) P = Platy AP = Acicular Platy 3) Measured, by N2 Adsorption. Desertal 57 58.10 29.21 4.46 0.35 1.10 - 16.0 7.0 AP 5-7 ABS-043944 OJ 1 r 1 III PQ 0 0 rH CO 01 0 OJ IA O LTN OJ ON . . vo VO IA pH VO PT LA m H 0 ON rH 10 OJ OO PQ 0 1 0*11 ro NO -d* O rH LA O LTV P* OJ LA VO .. miAh- VO d CVI IACO ON rH T a b le 3. PROPERTIES OF EXPERIMENTAL TALC-FILLED POLYPROPYLENE 80 Ed O 1 O 1 1 1 -3 LO LO -3 I 1 NO On 1 H t?0 I t--3 ON rH EdON eo Io NO 1o -3 o CO >s CO 0 co H CO CM t-- 0 CO NO ro CO rH l/N CO O CO opqn O 1 1 IO t-- co O ON LA O ro CO ON-3 CO rH CM CM pj- t- rH t-- rH 0pq0 1 <g o O ON O -3 IA O -=r -3 O . rH LTN -3 C\J CO rH CM CM pr CO rH VO 0 CO Ed 0 00 CO CO LTN co 1 1O 1 OJ CM -- CO LA CO -3 CNI CVI CM 00 H 0 rH cpqo 0 c- 1 1 r0o 1 0 CM O CO r CO -3 CO CM CM c-- cm' CM NO 00 H -3 O NO Ed co Q 1 1O 1 NO O CM H CM -3 CO CO -3 CM ON CO CM VO rH OO rH co 0 UA Ed 1 1 1 -3 1CO 0 OJ 0 ft VO ON -PN p* OJ OJ tCM* ON LA CO rH CVI rH 00 1pcqo rO t-- iQii m 0 co 0 t-- LA ft on ro oj CO . NO CO NO CM H Q p* 1pq 00 1O NO 10 1 1 p* O O vo CO . . VO CO ro p* Ol O NO CM* aCoO trH o O p* 1 -3Ed O 01 1 1 O IA O . LC.N rH LA LA 00 CO OJ co la ro OJ CM CO H rH 1 000 co ON 0 01 1 0 LTN O IA . . r--n CM CO CM VO rOo CO c-- ro CO LA ro OJ CM H rH W Pi 1 0 O1 1 1 NO -3- O O LA ON. VO. vo CO c-- CO vo CO roj- oj rH t-- rH I ,C0O CO LA >R LA >R cR c -CPO oto PC OJ c5 o\ rl o H -p po -mp TH3 <D 4) - P> eo C O rH C R >i >> Eh Pi CO U CO ft a) la in' +o> 0) H c H CVI O M rH C a) i* $ WH (40) +>I P <fa c &. -P co 4) . JC P0P0 S 4 520 +(30 rH ft Pi v OP O PO f4a) +W> P- Pr O . . <0 3 P PoL.'-' raoH,. >R P C NO O m ao (fa ao +> rH CM P p p p Ha) L1A -<P0 P> -P <n 01 CO CO OJ a) v O o oo w ) C0O H 1 -p CO rH c 0_) Eh O Ed in 3 Pi rH U3 N>Mr3 O1 a) r (fa O CO .+aCa>; cfto- H t-- (fa -P & O * "P (0 CO (0 -H to P. SI Ed id NO 5 tJ CM -P ~ -S ID P fa rH iS Q C 4) OP 3) O 4) P> g CO (0 dig 40 [V DO iro I'SJ* !0 rH CM fC F le x u ra l M odulus, p s i 12 5-0 Notched Izod Impact a t 73F, f t - lb / in . k.O 3-0 Typical___ -___ __ Unmodified V-526 2.0 Legend: Talc Particle Size, Particle Shape Max Avg - Mistron Vapor #- Mistron Super Frost - Mistron Frost O- Desertalc 57 Platy Acicular Platy Acicular Platy Acicular Platy 6.0 6.o 10.0 16.0 1.0 1 10 20 30 Talc Content, $ 1.0 0.8 3-0 7.0 ho 50 Figure 2. INFLUENCE OF TALC CONTENT, SHAPE, AND PARTICLE SIZE ON NOTCHED IZOD IMPACT STRENGTH AT 73F OF FILLED SHELL POLYPROPYLENE V-52ft ABS-0 k394t Y ie ld E longation a t 0.2 in ./m in , F le x u ra l Modulus, p s i ABS-043949 Notched Izod Im pact a t 73F, f t - lb / in . G O CJ -H >P oo COrH P CO PO p P c 2 --1 a Eh CO on on C\J -d O <--1 i--I cPo OJ 1 t-- t 1 CM 4.0 pCO OJ oCO H H . CM CO vocg*3 > &H <: VO on P LA vo ii i t-- t-- OJ o vo 1 a a|P. o 'd o Ph aoP,I rH H VO H OJ o C*h la Q VO 11 O Cr\ o > .d* on -d LA CM 00 CM t-- r- vt~o- urn- H OJ o on p" ON CM 8 on CM OoJ rH o a rH M CO H Eh M C*H Ph O 'ad) rH CO H rH oo O in O m O CM $W H C\J p LA H tH frn IT\ o P LA rH -d* t*- t-00 rP CM i p" rH 1 os O > n8 ll 8 ll 8 8 88 s o rH CO EH Ph CO Ph Qo E-i *d 0) O rH A iQ M rH oH 3 oCO 1 LTV oO LA oH <0 p Q on p O O LA LA LA LA cm on rH p CO 00 rH CM * LTV LA t-- On Ip CM on 8 rH JS 13 CJ P -d Eh P 3 rH Oa rQ rH CO O G Eh la oVO rH oi s CM c-- 3 -d- -4- O vo -d co on. on LA ON t-- OJ lO ovco Ip CM LA vo & 1 LTV on CM vooo o rH CJ CO J3 G &a G3 J3 G *O 13 *H CJ P OJ H G u ip O 3 (p P P po A CO (0 1 P OJ z G O 13 p ce o2 1 p G ip co P p ca . c rH Q e 4) s a *P z E-i H G O A a po CJ OJ JS pi p iH (0 d oM \ a> P> > a> C A (P b0 c 0 P $ CO H C G Oh d 1) 0) *d PG 0 i3 ip Oi aN p asH <M o 0 Ph O JZ CO Oo o H 4J s s Ph *rf rt G P G OJ N*. O 'NS>% H p Ph Ph G O & C d X 3- O rH *H a) A (0 0 CO CO P P Ph Ph CO O rQ G CO G O (0 H 13 CO CJ PG G3 CJ co ai CO (0 Po CO CO h -d* vo CO rH >> C p ID pat G i--i A ip ip p C UJ H U Ph vm 0) a> Q vo vo 3 R ir\ P tO *c3 c *d CM -P P> H CO P CO Ph (U 6 ip G CJ O G P Ph Ph CO P -P CJ rH C P rvrH. CC-J, CM rrH. rH *"C\ to CpOp 0 <D flj CO H 4! CO