18 Properties-to-Composition Relation of ABS
Downloaded by UNIV OF CALIFORNIA SAN DIEGO on December 19, 2016 | http://pubs.acs.org Publication Date: June 1, 1975 | doi: 10.1021/ba-1975-0142.ch018
Resins by Statistical Analysis MARIO CATONI, GIUSEPPE P I Z Z I G O N I , a n d I S I D O R O R O N Z O N I Montedison S . p . A . , Divisione Petrolchimica, F a b b r i c a d i Castellanza, Castellanza, Italy
A study of the principal ABS plastics on the market was made in order to determine the relations between some main physical-mechanical properties and composition specifications. The statistical methodology of multiple regression was used in the investigation. The mathematical models obtained for most of the tested properties were well explained by second order and linear polynomials. The expansion of mathematical models enabled us to calculate the best estimates expected for the physical properties whenever the ABS compositions were known. The plotting of these polynomials obviously represents a qualitative picture of the physical properties-composition relations in the wide experimental range of the variables.
S
ome general information is available about the relationships between the properties a n d the compositions of acrylonitrile-butadiene-styrene ( A B S ) resins (1-6). It usually presents a qualitative picture of the dependence on the A B S composition of only particular properties (7-15). A n early mathe matical approach was b y Dinpes and Schuster i n West Germany (16). In this work, data o n 48 commercial A B S polymers from five different producers were elaborated b y statistical methods (17) i n order to determine i n more detail the relationships between some physical properties and the composition of A B S resins. Because of data uniformity, A B S polymers con taining «-methylstyrene were not included i n this study. Experimental T h e physical properties of 4 8 commercial A B S samples from five different producers were related to the composition b y regression analysis. T h e follow i n g were chosen as independent variables. X i — P o l y b u t a d i e n e Content ( P B ) . X was measured b y I R spectropho tometry on hot-pressed film samples; it is expressed as w t % of the whole A B S (i.e. including all additives). T h e observed variation range was 7 - 2 8 % . X — A c r y l o n i t r i l e Content ( A N ) of the Free S A N C o p o l y m e r F r a c t i o n . X was determined from the nitrogen content of the acetone-soluble fractions; it is expressed as wt % of the whole A B S . T h e observed variation range was 13-25%. 1
2
2
192
Platzer; Copolymers, Polyblends, and Composites Advances in Chemistry; American Chemical Society: Washington, DC, 1975.
18.
CATONi
ET
193
Properties vs. Composition
AL.
X — G r a f t e d S A N Copolymer Content ( S A N I ) . X was determined by gravimetric analysis of the acetone-insoluble fractions; it is expressed as wt % of the whole A B S . The observed variation range was 0 . 5 - 2 0 . 5 % . X — I n t r i n s i c Viscosity of the Free S A N F r a c t i o n [ r ç ] . X4 was measured in dimethylformamide at 2 5 ° C on the acetone-soluble fraction; it is expressed i n d l / g . T h e observed variation range was 0.45-1.10 d l / g . X — E x t r a c t a b l e Substances Content. X was determined by extraction in a cyclohexane-methanol mixture; it is expressed as wt % of the whole A B S . The observed variation range was 1 - 5 . 5 % . X — A s h Content. X was determined by burning a sample to ashes at 8 0 0 ° C ; it is expressed as wt % of the whole A B S . The observed variation range was 1.0-7.0%. The following physical properties were considered dependent variables. Y Y and Y — F l u i d i t y . These values were determined b y measuring the length of injection-molded spirals at 190°, 2 1 0 ° , and 2 3 0 ° C respectively; they are expressed i n cm. Y — T e n s i l e Strength. Y is the yield strength measured according to A S T M D 638; it is expressed in k g / c m . Y — I z o d Impact. Y was measured on notched samples according to A S T M D 256; it is expressed in k g cm/cm. Y — R o c k w e l l Hardness. Y was measured according to A S T M D 785; it is expressed in units of the R scale. Y — D e f l e c t i o n Temperature. Y was measured according to A S T M D 648 under a load of 18.5 k g / c m ; it is expressed i n °C. Other characteristics that were mainly structural (e.g., dimensions and structures of elastomer particles, and molecular weight distribution of the plastomers) and that also have considerable effect on the physical properties of the A B S polymers were not considered i n this study. 3
3
4
5
5
Downloaded by UNIV OF CALIFORNIA SAN DIEGO on December 19, 2016 | http://pubs.acs.org Publication Date: June 1, 1975 | doi: 10.1021/ba-1975-0142.ch018
6
1 ?
6
2 ?
3
4
4
2
5
5
6
e
7
7
2
Mathematical-Statistical Analysis The data on the commercial A B S polymers were elaborated according to the statistical methodology of multiple regression (17, 18, 19, 20, 21). The rela tion between a given A B S physical property ( Y ) and the composition variables ( X ) can take the form of the following quadratic polynomial equation (22, 23, 24): Κ Y = βο + Σ i= \
Κ 1 κ κ + Σ Σ β,-yXiX,· = Σ βϋΧ*< + ε i=\j=2 ι=\ α
