Table 7.

Regression coefficients in final reduced second-order polynomial models

	Particle size		PDI
	F-value	P-value	F-value	P-value
Linear effects
X1	60.79	<0.0001a	35.45	<0.0001a
X2	20.28	0.0004b	16.92	0.0009b
X3	192.07	<0.0001a	27.5	<0.0001a
X4	70.76	<0.0001a	24.78	0.0002a
Interaction effect
X1X2	0.003	0.9574	0.16	0.6993d
X1X3	5.8	0.0294c	16.71	0.0010b
X1X4	4.52	0.0504d	0.28	0.6041d
X2X3	1.37	0.2595d	71.11	<0.0001a
X2X4	11.27	0.0043b	48.53	<0.0001a
X3X4	106.01	<0.0001a	59.7	<0.0001a
Quadratic effect
X12	62.16	<0.0001a	8.69	0.01c
X22	12.62	0.0029a	8.52	0.0106c
X32	0.23	0.639d	5.66	0.031c
X42	0.058	0.8133d	0.001	0.9744d
Lack of fit	2.53	0.1592d	0.57	0.7885d

Notes:

^aP<0.0001;

^bP<0.01;

^cP<0.05;

^dP>0.05. X₁, X₂, X₃, and X₄ are the linear, quadratic, and interaction terms of the quadratic polynomial equation, respectively; X₁, temperature; X₂, addition rate; X₃, water content; X₄, mixing rate.

Abbreviation: PDI, polydispersity index.